DIY: Vanos hub + bolts

[Casa de Mesa]

Originally posed by SYT_Shadow on Jun 17, 2012 on M3Forums.

A couple comments:
I used this as a second reference to the Beisan Systems DIY instructions when doing a complete Vanos rebuild. This is particularly helpful because it had better pictures than the Beisan Systems DIY in certain key spots, and also explained things in plain English pretty well.

There are a couple of things in here that can be done differently than shown - like cutting the shroud for the fan (don't need to), removing the fan from the bottom (it can be removed from the top, hence you do not need to remove the oil cooler). Also for torque specs, use a manual or THIS PAGE or the Beisan Systems instructions. When I did this job 2 years ago, I had this DIY open locally on my laptop and the Beisan instructions. I did a full vanos overall, including new chain guide, refurbished solenoid, anti-rattle kit, etc. - pretty much everything in Beisan's S54 catalog. I used the Beisan instructions primarily, then use this DIY as a secondary reference. Like I said, these pictures are in some cases better than the Beisan instructions and the way that SYT_Shadow explains things is really good.

Overall this is a fantastic DIY. Kudos to SYT_Shadow - recreating this was a monster, so the original body of work is all-the-more-impressive. These DIYs have saved me countless Benjamins, so a very big thanks to anyone who puts themselves out there and creates a DIY like this.

Hope this helps others as much as it helped me.

-Casa
---------

Finally!! Here goes!

I apologize for taking so long to post this. I hope this is a useful DIY for those looking to change their OEM hub for Turbotoy's (or another OEM one), change their infamous intake bolts out for new ones or just check to see if their hub is still intact.

It is not hard to do this work, and now with these pics it should be a bit easier!

I am going to try to show every single step. I don't know about you guys but I get quite frustrated when steps are taken for granted. The first time I opened this up I spent more time screwing around with the fan than anything else.

Disclaimer: These instructions are what I did. In no way does this guarantee you similar results. Opening your engine and fooling around with the timing can damage the car, the engine and you.
If you plan on following these steps, read the DIY several times to become familiar with it before starting.

Note 1: Yes, I am aware that oil is leaking all over the place. It isn't the CPV, but it's somewhere towards the front-right of the engine. If you know what this could be please PM me, no need to clutter this DIY up

Note 2: I don't mention any part numbers in this DIY. I get all my parts through Mike Kent at thebmwpartstore and never have to look up PNs, so I don't know what they are.


EDIT: Due to popular demand I asked Mike for the PNs. Here they are, along with pricing at thebmwpartstore:
Item---PN---Total Price
12x interior vanos hub bolts---07129905536---8.16
1x timing tool---83300493749---117.19
1x extra lock pin---83300491086---28.03
1x vanos gasket---11367831938 ---9.92
1x valve cover gasket---11127832034---50.72
6x spark plug gasket---11127831271---39.24
2x rubber seal (bolts)---11121437395---1.56
13x rubber seal (bolts)---11127830972---10.92
2x copper ring for banjo bolt ---07119963129---0.44


EDIT Note 3: I don't post the torque values because I didn't use a torque wrench and don't have access to the TIS or the Bentley manual. Even if I did, I don't trust an uncalibrated torque wrench with my engine parts, I would prefer using blue loctite if a bolt is keeping me up at night.
As a general guideline, bolts marked 8.8 are weaklings and will break or strip with any hint of 'tight', so be careful with them. They're usually threaded into aluminum or iron and that will not take much pressure before stripping. All the exterior Vanos bolts are 8.8, and you'll notice that after dismounting it several times you'll need to replace them. I replaced them all.
The interior vanos bolts are 10.9, which are strong bolts. These typically thread into steel and can be tightened properly. The torque ratings for the one you'll find inside the vanos are 10-14 lbft.

EDIT Note 4: Some people are asking for the PN of the extra pin I have for the timing tool. TDC Pin: 83300491086. Note you can use a long screw driver if it fits in the hole of the timing tool and is long enough to fit into the cam while inserted in the timing tool.

EDIT Note 5: Some brave individuals unlock timing and then decide to do a valve adjustment while they're at it. BAD IDEA! You can do them together but sequentially, not in parallel.
Option 1: valve adjustment. Afterwards do vanos work but start it with your engine in the same position as these pics!!!
Option 2: vanos work. Afterwards do the valve adjustment

EDIT Note 6: There's no need to lock the top's timing as seen here. You can lock only the bottom, do your vanos work and then come back and lock the top before setting it back up.
Needless to say, do not rotate the engine or the cams freely unless you know exactly what you're doing.

EDIT Note 7: Some of you are trying to remove the exhaust hub and not able to because you can't access the hub's splined shaft. In order to solve this, I set my timing wrong to replicate the issue and have detailed instructions in post #3

EDIT Note 8: As of 7/8/13 my TT V3 hub has 30k miles on it. I dismounted and took some pics. You can find the thread if you look for threads started by me. It looks just like the day I got it! Very impressive

LIFTING THE CAR
Yes, I'm even going to go over this

You'll want to jack the front up using the center front mounting point. My car is not lowered and I still have issues getting to it without lifting the front wheels using 2x4 planks of wood.






Here we see the center jacking point


And it's up!


REMOVING INTAKE
This is held on through 3 clips. Use a screwdriver to remove them completely.
Once they're gone, take out the front intake piece and then the small elbow which is joins the large piece to the actual airbox.


REMOVING PLASTIC UNDERBODY TRAY
As soon as you get under the car you'll notice a black plastic tray which goes right under the engine. We want to remove this. I bought new bolts as the old ones were severely damaged.

In this first pic we see the center jacking point again




REMOVING FAN SHROUD + FAN + OIL COOLER
You'll notice the fan shroud gets in your way constantly. After removing it here I will not reinstall it, it takes way too long to mount/dismount this thing every time I open the Vanos up.
It's held on by 4 torx screws, two in the top, two in the bottom.

The shroud and the fan need to be removed at the same time. You'll notice they interfere in each others ways and are quite annoying. The oil cooler also manages to get in the way, but unlike the other two it's quite simple to remove.

To make our lives more interesting, BMW engineers decided to put a part of the shroud (a small part on the right) in between a cooling tube. This means it can't be removed and just stays there annoying you as you try to remove the fan shroud. I suggest you cut a portion out to be able to install/uninstall at will.

One


Two


Three


Four


The oil cooler is also held on by four bolts, two per side





Hold the oil cooler onto the car with a cord so it doesn't bend too much



Now the shroud will be loose but it still won't come out as the fan is blocking it.


There's a special tool to remove this but I prefer the following method. Get a 1 1/4 open ended wrench.


Place it on the fan nut


Hammering time! We want to move the wrench clockwise. The pulleys make it hard to move in that direction, so by hammering it we'll get it loose. It usually takes several whacks and I suggest you first look at the path where you'll be hammering to avoid breaking stuff.


Success! However the fan is still stuck because of the shroud.




We disconnect the wiring harness from the fan shroud


And now we jiggle the shroud and fan around until we can take it out. The fan comes out through the top


And the shroud through the bottom



Now there's just that little piece of shroud that's held on by the cooling pipes


I used a hacksaw. If you do it like I did it you'll still be able to reinstall and use it. There's a push-pin on there to fasten it to the shroud, you don't want to saw it off.


REMOVING STRUT BAR
There are many designs out there, but we have to remove the center portion to have access to the engine cover.


REMOVING CABIN FILTER
Whenever I remove this part I wonder why it's so damn heavy... must be two pounds of plastic right there!

Pop the top off by twisting those three clips. Remove the cover.
Underneath you'll see the cabin air filter which you may want to replace.


Once you remove the filter there are 4 torx screws which allow for removal.


You will also notice some cables are piggy backing on the cabin air filter structure. Remove them before removing the whole tray.



REMOVING ENGINE COVER
Quite straight forward. Be careful not to lose any bolts


There's a pipe on the top of the engine which has to be disconnected before removing the engine cover.


And it's off!

REMOVING COILS
This black strip which holds some cables is bolted onto the valve cover using the bolts that were on the engine cover, so it's loose once you get to it. All the coils are connected to it, so unplug coils one by one




To remove a coil I find the easiest way it to put one finger inside the plug which is now disconnected, then raise the tab. Wiggle the finger that's in the plug side to side while pulling out with the tab.


As soon as you take a coil out put something inside the hole it goes in. Leaving it empty is just begging for something to fall inside. On my 330Ci I did the same job and one of the valve cover bolt/washer/rubber assemblies fell in there and removing it was a nightmare!

REMOVING VALVE COVER
It's attached with a bunch of bolts. The three that are in the front are different than the rest, and the one that's in the middle is different than the other two (it's larger).
If you haven't changed your valve cover in a long time the rubber cushions that are attached to the bolts/washers will be all worn. Replace them.



If after removing a bolt it detaches from the rubber cushion, remove it with nose pliers are reattach it to the bolt/washer assembly


There we go, all the bolts/washers/cushions together


We continue. On the left side of the engine there are two bolts.


One is for the oil return line. There are two crush washers here. The inner one has a tendency to go bye bye, so buy a few spares before starting. They should both be replaced anyway. I also replaced the hollow bolt.

The other is a ground.


Now, remove the valve cover. Easy does it. If your valve cover gasket hasn't been replaced in a long time it will be brittle. Replace it before reinstalling.




After removing the valve cover, it's a good idea to cover the engine up with something. You do not want critters, leaves or other junk getting in there.


We also disconnect the wiring loom at the top. It's attached with two bolts.


Now we can see the Vanos exhaust hub. Mine looks different because I have turbotoy's. This modified hub doesn't let you see if the tabs are broken without dismounting the rest of the Vanos, but more importantly, it locks the tabs inside the Vanos and doesn't let them fall into the timing chain and blow a hole through your block.
This is how you perform the 'wiggle test' to see if your intake bolts are broken. I'll take you through the replacement steps later on.




SETTING ENGINE AT TOP DEAD CENTER, POWER STROKE CYL #1
Please read the FAQ in post #3 to better understand what we're doing here.
Some people get confused in this part. Basically, what you want is for the OIT marking on the flywheel to be aligned with a hole there. Additionally, you want the first cylinder's intake and exhaust cams to be 'facing each other'. Let's see some pics

You can rotate the engine several ways. One is with a big 32mm socket like this:


I prefer reinstalling the fan and then using the big wrench to turn the engine.


Reinstalled!


TIMING THE BOTTOM
Now let's see that OIT marking the flywheel has:

From the top:


From the bottom



We'll use a 1/4 inch extension to see when it's aligned properly. After this point no more playing with the bottom


TIMING THE TOP
I use the BMW timing tool. Seriously, for $130 I don't know why you wouldn't have it. It's perfectly possible to time the top using a screwdriver, but I prefer this. When you buy it you'll notice it only comes with one push pin. I bought a second one separately as it allows me to lock both intake and exhaust.
You see, the cams each have a hole in them that passes through their body. You want these hole to be 'straight up' following the engine's slight angle in the engine bay.
Here you can see the holes in the cams

Those holes go through the cams as mentioned before. If something is FUBAR in your engine it would be possible for those holes to be pointing upwards but the first cylinder's lobes not to be looking at each other. This is a big nono. You want the holes pointing upwards and the first cylinder's lobes to be facing each other.

It's extremely likely that your exhaust camshaft isn't aligned upwards. You'll notice the cams have some shallow hexagons which allow you to use a wrench to turn them and get them timed properly. You'll need a thin profile 24mm wrench. Normal ones will not fit! [If you need one, PM me]
This is useful is the push pins of the timing tool can aaaaaalmost go in the holes. If there's a big difference don't go nuts trying to force the cam to move. Once we take the Vanos hubs out it'll be very easy to move them so you can time in then. [Additional information in TIMING TOP PART 2] [Timing FAQ added to Post#3]


Timed! Remember it only has to be timed before starting it, so if you weren't able to get both pins in don't worry, we'll get another chance once the vanos is fully dismounted as then the cams float and can be moved easily.


REMOVING VANOS + VALVE BODY
Start with the oil line. It also has 2 crush washers. Like the other banjo bolt, I replaced both washers and the bolt.



Five bolts hold the solenoid and vanos valve body assembly. Be careful when removing them as the valve body/solenoid will fall right out and will also leak oil right onto the belts.

Unplug the solenoid connector before finishing the bolts


Ready to remove!


The vanos valve body and solenoid are now out. This part you see if the vanos pressure plate. These things leak eventually through the seals.
My seals look all nice and fat because I got Beisan System's seal upgrade kit which should last forever. My solenoid has also been modified by Beisan.


REMOVING VANOS 'CAPS'
You'll want to remove these to be able to press the internal cylinders in/out for reinstallation. Oil will come out. If the engine was on recently it'll be high pressure oil.



Once the three bolts are off you can tap it with a rubber hammer to take them out. The intake/exhaust caps are identical and they can only be mounted one way, so don't worry about that.


Off!


REMOVING VANOS CONTINUED
Three bolts under the Vanos, in the area that used to be covered by the solenoid and valve body


There are two bolts, one on each side of the vanos. Remove them partially



My valve gasket was installed with RTV so I had to remove it. Be careful not to scratch the surfaces.


There are two bolts which hold the plastic chain guide. Remove them



Remember how I said to not remove the two exterior Vanos bolts completely? They'll be used to support the vanos as you pry it away from the engine. Once you've broken the seal (this is a gasket which should be replaced), it'll look like this. Another (better) option is to replace those short bolts by the long ones that held the solenoid on. This way you can slide the vanos in/out without putting undue stress on other components.
Before doing this you should plug up any holes you see where the chain goes into the engine. If you don't, something can fall inside and you'll be faced with removing the oil pan. I did that (I'll post a DIY) and let me tell you, you do NOT want that to happen.


Peak inside and you'll see what is preventing Vanos removal: tiny little shafts on both the intake and exhaust vanos that have little bolts in them. One bolt is 7mm, the other is 10mm. Remove them. These are reverse threaded!


Unscrew one a few times, then go to the other to unscrew. The idea is to remove them together.



Once both are removed, you can remove those two exterior bolts you left in place to slide the vanos in/out. Now you can fully remove the Vanos


My Vanos! Here you want to put your fingers in the holes of the pump and see if it turns properly. At times the pump fails and you'll notice immediately if you try to turn it.


Here are my intake/exhaust hubs. Do you notice anything wrong?


Both tabs are sheared off! And of course, they're now sitting in my oil pan!
[After this event the hub design was modified and I'm now running v3.0 that's twice as strong as this one and is better built to withstand fatigue failure]



Anyway, behind the Vanos you'll notice a gasket. This should be replaced before reinstalling


REMOVING EXHAUST HUB
If you haven't stuffed the holes that lead into the engine with towels yet, stop and do it.

There are 6 exhaust bolts.


Once the bolts are removed you can take the exhaust hub out.


There's a washer-type ring behind the hub. Take it out. You'll notice the 6 white torx head bolts underneath it. These are the updated versions which I've already changed.

The back of the hub has a second washer-type ring. Notice the wear marks so you'll reinstall correctly


You can remove the splined shaft if you wish.

REMOVING INTAKE HUB
This is the same as the exhaust hub.




You see those white bolts with the torx heads? These are the ones that break often and I've already replaced mine with the updated models.
There are a few doubts about whether these are better than the old ones, but I haven't had any issues with them.


The splined shaft and washer can be removed



TIMING THE TOP, PART 2
If you weren't able to time the top before you can now. The cams are floating and can be moved at will at this point. [Additional Timing Info in Post#3]

Notice the first cylinder's cams are facing each other.


Use the 22mm wrench to move each cam


There we go!

[Casa de Mesa]

PUTTING IT ALL BACK TOGETHER


REINSTALLING INTAKE HUB
Before starting, grab the correct splined shaft. The intake and exhaust ones look identical but they're not. The difference lies in the length of the bolt that is used to attach itself to the vanos body. Here is how they go (left one goes into the exhaust hub, right into the intake hub)

Screw two bolts back on at 180 degrees from each other. I used new bolts. Just screw them on lightly.
These bolts screw onto a center part which turns easily.
So, screw two bolts on but not so tight that it can't rotate anymore. It should allow around 30 degrees of movement in each direction if you're doing it properly.



At this point you can either screw the rest on lightly so it still rotates or not put in additional screws. If you don't, you'll put in the rest once the first two are tightened.


Now, rotate the intake hub all the way clockwise. Like I said before, you should be able to rotate left and right. Move it all the way clockwise until it stops moving.
Rest the spline against the hub. You'll see it doesn't go in. SLIGHTLY turn the hub counterclockwise until the first tooth engages and you can start sliding the splined shaft in.
[Additional Information in Post#3]


To understand this in a different way, you want the splined shaft to be able to go all the way in and out without falling off the intake/exhaust hub.
Here you see me testing the innermost portion of the splined shaft


Once we're confident we have full range of movement, we'll rotate the hub until we reach this position. You should barely be able to see the teeth in the splined shaft.


Tighten the bolts in a star pattern.


REINSTALLING EXHAUST HUB
Follow the same procedure as the intake hub. If you have a modified hub like mine you won't be able to tell when the 'teeth are poking out' which we used earlier. In this case, set it so that the outside portion of the splined shaft is a bit further inside than the outside of the hub. This will guarantee it doesn't smash into the oil pump.
When finished it will look like this:


This is what my Crome-allow 4340 hub looks like

REINSTALLING VANOS
Now we'll use the new gasket. Also apply some RTV to it.


You can use the RTV to stick the gasket onto the engine so it doesn't flop around and annoy you.


Next is threading the little bolts of the splined shaft and the vanos assembly. These are reverse threaded!


We'll use those long bolts to hold the Vanos while we bolt up the inner shafts


This is why you have to remove the 'caps': you can push the cylinders that mate up with the splined shafts in with your fingers


Line them up


And bolt them up






Now switch the long bolts we were using to slide in/out for the proper ones and screw the bottom 3 bolts on



The vanos should now be attached to the engine


The top bolts which hold the chain guide on


The new banjo bolt with new crush washers


Reinstall the caps


Reinstall the vanos valve body/solenoid along with the sealing plate


Looking good!


Don't forget the plug that powers the solenoid



REINSTALLING THE VALVE COVER
My old cover and a brand new one! I'll try to keep you from making the same mistake I made...


Notice the engine is perfectly timed. At this point, remove the timing tool


Put the cover on the engine

Put some RTV sealant in the areas you think it could leak


Now, BEFORE doing anything else, screw in the banjo bolt that goes on the left of the engine.
The first time I did this I first bolted the valve cover on and then spent a few hours trying to get the banjo bolt to fit. In the end I figured it just needed some love from an open ended wrench and the result was I stripped the threads inside the valve cover (the bolt was just fine thank you) and instead of using a helicoil to repair it I bought a brand new one, which is the one you see.
So, once the valve cover is in place and not bolted on, try to thread the banjo bolt in with your fingers. Don't forget the two washers! Thread it in all the way. You can tighten fully once the valve cover's bolts are on


I took a few pictures of the evil hole of death


Does it screw in with your fingers? If so, go ahead and tighten it a bit. You can finish tightening once the cover is screwed on


If it doesn't screw in with your fingers, try installing a few bolts on the engine cover and try again. Do not think about forcing this bolt in! Any metal shavings will be in the oil system and can screw things up. In my engine this bolt wants to be screwed on before bolting up the valve cover but yours may feel differently.

Continuing with the valve cover install. Remember, you are not bolting up the Golden Gate Bridge. The fact that the bolts have rubber cushions attached indicates we should screw it on gently







The front ones are different. The middle front one is the fat one, the other two are the same.


Don't forget to reattach the ground


Now, remove what you used to plug up the coil holes and install the coils. I also used brand new coils as mine were old, but this isn't necessary.
When you put a coil in, push down on it hard to make sure it goes in all the way. A loose coil means a misfire sooner or later.
So, we reattach all the coils and then put the cable holder on.





What's left:
- Attach engine cover
- Plug oil pipe into top of engine cover
- Reinstall cabin air filter assembly
- Hook up cable bridge to the cabin air filter assembly
- Reinstall sway bar

And we're good to go!

I hope this was useful.


SYT_Shadow

[Casa de Mesa]

If you can't access the splined shaft's bolt on the exhaust side, here are the instructions

You'll notice that when you try to separate the vanos unit from the engine in order to reach the splined shafts and disconnect the pistons which transmit the movement from the vanos to the splined shafts, you can't separate the vanos enough.
It's jammed in place because the exhaust is out of time.
No worries, it can be fixed!
Your engine will look like this:


Make sure you put shop towels inside the timing chain's hole. This is not funny, you do not want to see the other DIY of dropping an oil pan. People drop the 7mm wrench in there along with bolts, etc.
I like using a nabber grabber for this


Here we see that the bottom of the engine is locked with the BMW crank pin. Highly recommended! This is part of the kit I send out for Vanos work.
We will have to remove it in order to do the next steps.


See? No space!




Visually it is hard to tell if you're not going to be able to pull out the vanos. As you see, my exhaust hole isn't facing 'up' all the way but it isn't way out of whack either


Ok! Time for the good stuff
-Remove the crank pin
-Rotate the crank two times using the fan clutch, fan or the 36mm socket that fits in the crank. If you rotate the bottom two times you will see the alignment pins on the cams again but this time the first cylinder's lobes will be facing opposite each other
-Remove the three external hub bolts from the hub
-Rotate the crank twice again. Now you should be in the same position you started!
-Lock the bottom with the crank pin when the first cylinder's lobes are facing each other
-Remove the remaining three bolts on the exhaust hub
-Rotate the cam in the direction necessary for the hole to look 'up' using a 24mm thin wrench or other tool. As you do this you will see the spline comes 'out' to say hello and you can finally separate the vanos from the engine!

Before:


After:


Success!!



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If you've dropped a tab in your oil pan, here's the DIY:

http://www.m3forum.net/m3forum/showthread.php?t=414678

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Timing FAQ

Question #0:
What's up with this OIT and 'lobes facing each other'? I don't understand why OIT doesn't guaranteee the 'bottom end' being timed.
My exhaust tabs were broken and the engine was off time! The lobes aren't facing each other!

Answer: [this is for people who are just opening the engine up and haven't loosened the hubs or inserted the timing tool yet]
So many people are running into issues here that I thought it was important to clarify this ASAP.
This is especially the case if your engine doesn't have the front cylinder's cam lobes 'facing each other' like in my pictures.

If your exhaust hub is off, meaning it doesn't face cylinder #1's intake cam lobe, go rotating your engine with the 32mm wrench.
You'll see how the intake and exhaust cams are locked together with the bottom of the engine and rotate as you rotate the bottom.
Your exhaust hub is off, so you can safely ignore it. Focus on the intake hub, which has no issues. As you go rotating, at one point the intake cam's lobes on Cyl1 will be around 10-11 o clock. This will coincide when the engine bottom is at OIT or very close to OIT.
This is what 'timed' means.
At this point, you rotate the engine a little to get a pin in the bottom locking it into OIT. You don't move the bottom any more until you're finished reassembling!
Now, for the top, Once the bottom is locked on OIT AND the lobes of Cyl1 intake are facing around 10-11, you can dismount the intake hub. When you dismount a hub you remove the link between the bottom and top of the engine! When you dismount or unscrew the intake hub you can move it freely with a 24mm wrench.
Work on the intake hub (replacing bolts for example). When you're done, reinstall the intake hub following the instructions. Now you need the timing tool for the intake hub.

Notice I haven't mentioned the exhaust hub yet.
Now that you know for sure the intake one is finished, go ahead and dismount the exhaust hub, replace it or the bolts and before reinstalling, move it with the 24mm wrench so that it 'faces' the 1st cylinder's intake hub. Then you can use the timing tool before bolting it up to time the exhaust hub.

Question #0:
I get lost with a zillion pictures. Can you describe the whole process in a single paragraph?

Answer:

So, with the engine off, you install the pin on the crank/harmonic dampener at OIT only very slightly rotating the engine so it fits, then go to the top, verify both cams are more or less looking at each other in their first cylinder's lobes and the holes for the pins are more or less top-to-bottom, then remove the vanos hub bolts, do your work, then rotate the cams slightly so the timing pins and bridge fit, lock the bridge, then reinstall the hubs, then do the spline insertion method as described in the DIY, then tighten the hubs, then remove the bridge and pins and the crank pin.


Question #1:

Quote:

at what point of assembly or disassembly is the timing tool used? do you lock the cams in place, timed, after removing the cams connection to the pistons, and then leave it that way until you put it back together? is it a timing "lock" tool? is it used to check the timing after bolting it all back together? if you bolt it all back up and the timing is off, meaning the pins wont go in, what do you do?

Answer:
In this DIY you can see I locked them while dismanteling and left them like that for the rest of the time. So, as soon as I had access I put the locking pins in and I removed them before closing that area up.

However, this is not necessary. You can choose to time it when you're putting the engine back together. There is no reason why you can't move the cams around during the DIY if you time it before turning it on.

Maybe you should look at the DIY as you can see when I put the bridge in and when I took it out as well as the logic for timing the bottom and the top.

Remember that the timing of the top is only dependent on the timing of the bottom when the vanos is still on the car. That's the part that makes X degrees of movement of the bottom translate into X degrees on the top.
Once the Vanos is dismounted you can move the cams around freely, so after working on the vanos you need to time it again before closing it up.

If you bolt it back up and the pins don't go in then you weren't following this DIY (lol) as I have it in there the whole time. But suppose that were to happen: you'd have to loosen the exhaust and intake hubs (well, technically only the one whose timing is off) and then you'd be able to rotate the cams easily as the bottom and top of the engine become desingaged.

The only part connecting the bottom and top of the engine is the chain which you can see in the front of the engine. That chain connects to the vanos, whcih is why once the vanos is dismounted you can move each camshaft independently and freely.



Question #2:

Quote:

It does seem that 'locking' them in place before allowing the cams to move freely is the best idea. That way when you bolt everything back up from the vanos, it is all where it started and the engine is timed the way it was when it was shut down. What about reassembly make this difficult? When inserting the splined shafts, they want to rotate the gear and in turn the cams, correct? Is it possible to have the cams 'locked' in a position that will not allow the splined shaft to be reinstalled correctly and you must loosen the cam to install it? What you do then? It seems like you could end up installing the splined shaft, making sure it has full range of movement, if it doesn't removing it.. timing the cam shaft and reinstalling until it is in the correct place.

Answer:
When you first open your engine you may not be able to time both cams. The intake one yes, but the exhaust one is always a bit off.

To be clear, nothing about reassembly makes it difficult to keep the timing tool locked in there, which is why I leave it in the whole time.

When you insert the splined shafts you will have the timing tool inserted, so you'll move the shaft to match the timing, not the other way around. The spline can enter in many different ways and the point is to get it in in a position where a tiny movement of the hub allows insertion.

Let me explain this a bit more:
The splined shafts join the camshafts to the vanos hubs. The vanos hub is joined to the timing chain by those 6 bolts you see which bolt on to a floating disc inside the timing gear that's driven by the timing chain.
This floating disc is between the two gears which are driven by the two timing chains. It floats because it's only connected to the hubs and then through friction with the two gears once it's tightened. You can see it clearly in the pics

Now, with everything dismounted you:
-lock (or have it locked from before like I do) the cams into the proper place
-Then you thread the 6 bolts that attach the hub to the floating disc. You'll notice that floating disc moves and will continue moving until you tighten those bolts, which you will do later
-Now you should have the hub on but because of the floating disc you can rotate around 30 degrees in each direction. This is good, it allows you to set the timing wherever you want
-you move the hub all the way clockwise and try inserting the spline, which will lock the hubs to the cams. It doesn't enter
-you move the hub counterclockwise just a tiny bit, juuuust enough for the spline to be able to engage the hub. Additional explanation: the splined shaft has one side with helical teeth and another with straight teeth. The straight teeth go into the cam and the helical ones go into the hub. The number of teeth are different, so by changing where the spline engages the cam you can get a 'better' fit. A better fit is one where a smaller amount of movement in the counterclockwise direction is necessary to engage the hub to the spline.
-push the spline in. As the gears are helical you will see the hub moves when you push the spline in/out. It's able to move because of the floating disc it's connected to which we haven't tightened
-push the spline in until you can barely see the little teeth. You basically want the 'head' of the spline out of the way of the vanos assembly you're going to put in so it doesn't whack the oil pump
-Now, you tighten the 6 bolts. Gently at first and in a star pattern so the floating disc is completely parallel to the two gears it's inside of
-when you tighten these bolts you will have finished timing the top

Summing up:
You set the timing yourself when you tighten those bolts. You could put those bolts on in any position of the cams, so it's possible to 'time' the engine the other way around and ensure it's destruction. You have the timing tool to make sure the cams are in the right position when you force a specific timing by tightening those bolts.

This DIY can be done many different ways. This is, to my understanding, the easiest. If you understand what is happening then you can move things around to suit you. During this DIY I moved the bottom and moved the top separately and then had to time them together, but it's not smart to get into that and I left it out.



Question #3:
Explanation of inserting splined shafts by SMG333

Answer (by SMG333):

I know this will be added to the DIY but I wanted to share my experience with the spindles for others to know.

The process for setting the spindles is to turn the hub all the way right and back it off just a bit until the first tooth enters the hub.

**I did this but still did not have full range of motion with the spindle going in and out of the hub.

When speaking to Danny, he explained that there is one tooth around the spindle that will fit almost perfectly into the hub without moving the hub counterclockwise, only the slightest movement and it will slide right in.

My first attempt to put the spindle in (before second guessing myself and calling him) coincidentally did just that (eased right in)and had full range of motion.
My second attempt when i had to move the hub further counterclockwise to the first tooth did NOT have full range of motion in and out of the hub.

**These spindles have a sweet spot! Just a few spins of the part in and out off the hub and anyone will see that there is one tooth, or position that the spindles should be re installed. This "sweet-spot" tooth will allow for full range of motion and should keep anyone from further problems performing this job. It is an obvious difference than the other teeth, you will not need to back the hub up much at all with the correct spindle position.

As the OP told me on the phone. . Be sure to crank the motor BY HAND before turning the key. If you have a problem with timing you will feel the valve stop you from cranking by hand. This check SHOULD be done so nobody ruins their motor in this process.







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About TT hubs

[Disclaimer: I'm in no way affiliated to TT, Beisan, Dr Vanos or anyone else]

If you want to follow the history of this very important development for the S54 I suggest you start HERE

There have been three versions of this hub.
The idea behind them is simple enough, they use a stock hub with a soldered-on ring with tabs built out of a much stronger material. That ring also avoids the tabs falling into the engine should they ever fail, which is the real problem behind all these broken hubs: the tab getting caught in the timing chain will likely destroy your engine.
V1 used a 4130 chrome alloy for the tab area. I was a beta tester for this part and mine failed with 15000 miles. My original hub was intact before sending it to Turbotoy to get modified.
Given the intelligent design, the broken tabs didn't fall into a running engine.
The broken hub was sent to get SEM microscopies, and some pretty serious material and fatigue testing was done on it to determine what broke it. With this in mind, hubs V2 and V3 were designed.
V2 used a 4340 chrome alloy design. I removed mine after 10k to put a V3 on, but there are no reported failures of the V2 hub and mine is currently in another forum member's car, still working fine. Additionally, this hub uses fatter tabs which reduce slop and increase strength.
V3 goes a step further and uses a 300m steel which is extremely resistant to fatigue failure and also quite expensive. It's heat treated for further strength gains.
Mine has around 23000 on it, no issues.
Update 7/8/13: I now have 30k on it. I've opened a new thread about this. It looks perfect!

Everyone is free to do what they want, but as an engineer with a minor in materials science who was involved in the design of V2 and V3, I think this is the way to go to eliminate the dreaded vanos issues. And even supposing something were to go terribly wrong one day, the tabs would be safe from falling into the engine.

[TexaZ3]

Very nice. How many miles on this engine?

[Casa de Mesa]

Very nice. How many miles on this engine?

I do not know. The original writeup was not done by me, but by SYT_Shadow.

Judging by the coloration of the metals in the head, valve cover, etc. I'd guess somewhere between 80k-120k. But that is a complete guess.