SMG to Manual Bellhousing Machining

[pawelgawel]

question for someone who knows for sure regarding the swap;

I recently acquired a modified BH and everything looks great except as you can see the smaller cylindrical bearings are missing that are held by a retainer. Which means I will need to swap them over from the SMG bh on my off the car. my questions is, will it work to swap out the bearings without issues (are they pressed in or free?), and second, is it a good idea to replace both the main bearings, the cylindrical shape and the ball bearings we see in the photo?

[Mystic3]

Unless you're radius the lips on the drill you will certainly drill oversized anywhere from 3 to as much as 10 to 12 thousands hole could be eggy if you see that picture where someone is holding that drill it does not look like it's even straight that's another issue by doing it by hand

[Ob917]

Shift lights will work fine as long as you do the delete properly and have the clutch sensor wired up to the DME

The same DME input that the cruise control uses?

[sapote]

The guy in the e46fanatics thread I linked in the OP stated that the drawing was incorrect and that you could drill completely through. My only confirmation is the Wheeler Dealers episode as it looks like he drills straight through. The e46fanatics guy is MIA and hasn't responded to any texts (he left his phone number in his post).

I'm most concerned about how the sleeves stay in place without the little lip shown in the drawing?

Old thread but just in case someone has the same question. Whoever says the step is not needed and just drill straight through the holes, then they don't use the sleeves. The reason to have the steel sleeves is to avoid the moving pins wear out the soft aluminum holes, then the pins can lock up. Without the step in the holes, the sleeves can move in and cause problem.

[George Hill]

The guy in the e46fanatics thread I linked in the OP stated that the drawing was incorrect and that you could drill completely through. I'm most concerned about how the sleeves stay in place without the little lip shown in the drawing?

Whoever says the step is not needed and just drill straight through the holes, then they don't use the sleeves. The reason to have the steel sleeves is to avoid the moving pins wear out the soft aluminum holes, then the pins can lock up. Without the step in the holes, the sleeves can move in and cause problem.

sapote I think you misunderstood s54wagon statement (or maybe I have). On the original drawing referenced above the bore for the bushing is not drilled through, but leaves a step at the bottom. This would allow you to install the bushing to the same depth on every unit. s54wagon asks if this step is necessary. I personally don't think it is. When I mill a BH I go all the way through and then set the depth by eye when installing the bushing. ZF5 transmissions don't have this step and they don't have any issues with the bushing "moving" once installed even when the pin starts to stick.

But to reference your statement about the bushing, this is something I am curious about. Obviously BMW/Getrag thought there was a reason for the bushing but is it or is it over engineered? Look at the lifter bore on any traditional V8 engine, those are generally not bushing and the lifter is getting a partial side load acted on it by the camshaft lobe and they don't have any issues. Yes on big cams they do occasionally wear a bore but its not a common issue that every engine has that I am aware of. The only other thought is that they ARE positively oiled and the detent pins in the BH are splash oiled, maybe that makes the difference? My first (2) SMG conversions 7-9yrs ago we did not install the bushings and in the time my friend and I owned those cars we didn't have any issues, but I have lost track of both cars now so who knows. With that said I always install the bushings now and definitely think it is the RIGHT way to do it.

[sapote]

Without the step at the bottom of the bore, Murphy law says the sleeve can move in by the spring loaded pin that might be dragging in the sleeve by stagnant sludge oil in there. People had to replace the sleeves and pins in old transmission that pins are become sticky.

[sapote]

But to reference your statement about the bushing, this is something I am curious about. Obviously BMW/Getrag thought there was a reason for the bushing but is it or is it over engineered? Look at the lifter bore on any traditional V8 engine, those are generally not bushing and the lifter is getting a partial side load acted on it by the camshaft lobe and they don't have any issues.

Hi George,
Valve lifters don't have the steel sleeve/bushing because there is pressurized oil bleeding around the lifter puck (the groove around the puck OD) for lubrication, the G420 detent pin has no such luxury of fresh oil supply. If the BH doesn't have the sleeves installed, then I think the steel pins will scratch the aluminum bore and the byproduct sludge will jam the pin. We know that even with the factory installed sleeves, some people had the issue of the detent pins jammed due to the created contaminants and wear, causing the pin to cock eye and lock up.

As about not having the step for the sleeve, I think it's risk to have the sleeve moving inside. I don't think you want to machine the bore too tight for the sleeve, because pressing hard on the sleeve to install can cause it to deform then the pin will jam. Also if it is too tight, then it will be very hard to remove the sleeve for service in the future. And if the sleeve is not tight in the bore, then the movement of the pin will eventually pushes the sleeve inside, then the pin will cock eye and lock up.

[George Hill]

Hi George,
Valve lifters don't have the steel sleeve/bushing because there is pressurized oil bleeding around the lifter buck (the groove around the buck OD) for lubrication, the G420 detent pin has no such luxury of fresh oil supply. If the BH doesn't have the sleeves installed, then I think the steel pins will scratch the aluminum bore and the byproduct sludge will jam the pin. We know that even with the factory installed sleeves, some people had the issue of the detent pins jammed due to the created contaminants and wear, causing the pin to cock eye and lock up.

As about not having the step for the sleeve, I think it's risk to have the sleeve moving inside. I don't think you want to machine the bore too tight for the sleeve, because pressing hard on the sleeve to install can cause it to deform then the pin will jam. Also if it is too tight, then it will be very hard to remove the sleeve for service in the future. And if the sleeve is not tight in the bore, then the movement of the pin will eventually pushes the sleeve inside, then the pin will cock eye and lock up.

As stated above you very well might be right on the oil galley to the lifters.

As for the ZF5 pins, I really don't know how they lock up. Yes they do, I've repaired lots of transmissions even under BMW warranty, but its not because the pins themselves get cock eyed in the bore. When they pin is sticking you can't just wiggle it around and it gets loose you have to physically pull it out. To me that would mean something like the bushing has swollen and decreased the internal diameter, but IDK to be frank.

Have you every assembled/machine an SMG bell housing with the bushings? If not then I can tell you 100% there are a number of inaccuracies with your second statement at least in my experience.

As about not having the step for the sleeve, I think it's risk to have the sleeve moving inside.

You have to physically hammer the bushing into the bore. If it moves once it is in there its because either something catastrophic has happened OR the bore is the wrong size from the get go.

I don't think you want to machine the bore too tight for the sleeve, because pressing hard on the sleeve to install can cause it to deform then the pin will jam.

If the bore is to tight the pin will stick right off the bat. I drill the hole 0.5mm undersize and then I come back and ream it to size of 18mm. I do this manually on the mill, if you go to deep the reamer will hit the metal "stops" pressed into the BH so I watch and make sure I don't hit them. The distance from the end of the bore to the "stop" is not very far on one and if I go to quickly the reamer will pass through but won't fully be to size. The causes the bushing to deform at the bottom and tighten up the diameter which then presents itself as the pin sticking in the last little bit of travel. This sticking is not enough to keep the pin from moving but enough that it won't "fall" through its full range of travel. Whether you can feel this bit of resistance in the shifter IDK as I have always fixed the bore on the rare occasion this has happened.

Also if it is too tight, then it will be very hard to remove the sleeve for service in the future.

As noted above I have had to remove some bushings when I missed on the install, the bore being to tight in those cases made no difference in removal. The size difference from the pin moving freely to the bushing being to loose can't be much more than a 1mm or so (less than 0.5mm will cause the pin to stick). Besides without the step in the bottom of the bore removing the bushings with the BH off is extremely easy. You hammer the bushing in as far as it'll go and then you can collapse the bushing from the internal BH side and remove out the bore.

And if the sleeve is not tight in the bore, then the movement of the pin will eventually pushes the sleeve inside, then the pin will cock eye and lock up.

Again, I thoroughly do NOT believe the pin can ever jam in the bore in a way that would cause the bushing to "push the sleeve inside" if anything it would get loose and kind of rattle around, but again I don't think that could happen on something that you didn't 100% KNOW was faulty on installation from the get go. I've almost picked up ZF5 transmissions by a stuck pin (trying to get them out) and the bushing didn't move a mm. Also note that IF the bushing got loose it could never fully enter the transmission. The bushing CAN enter the transmission on a ZF5, a coworker messed up a bushing removal and knocked it into the case... he ended up warrantying the transmission.

[sapote]

As for the ZF5 pins, I really don't know how they lock up. Yes they do, I've repaired lots of transmissions even under BMW warranty, but its not because the pins themselves get cock eyed in the bore. When they pin is sticking you can't just wiggle it around and it gets loose you have to physically pull it out. To me that would mean something like the bushing has swollen and decreased the internal diameter, but IDK to be frank.

Interesting problem. No way that the old steel sleeve has swollen and its diameter become smaller. I have 2 theories:
1. I think the gap between the pin and the sleeve is filled with contaminant paste -- mixture of oil and metal powder (from pin and sleeve rubbing). Instead of replace the old sleeve (fold it inward then pull out), do you think if one just cleans the sleeve bore and the pin really good, lube with oil, install and they will work like new again? I saw videos that people made a mess on the aluminum bore when trying to fold the old sleeve inward in order to remove it. If it were me, I would try to clean the sleeve bore and polish it, instead of remove and replace it.
2. When the shifter is moved for the 5/6 or R gates, the ball bearing rolls over the detent pin ramp angle to press the pin out. The ramp angle is like 45*, so half of the afford is to push the pin against the sleeve, and this roughed up the pin/sleeve surface causing more friction. Imagine if the spring is not pushing back at the center of the pin, but offset to the ramp side of the pin -- this creates the worst case scenario that the combination of the ramp force and the spring force cause the pin to want to rotate (cock eye) and lock up on the rough surface.

I have this question and hopefully you can help with the data: The factory hole has a step, and the plastic seal cap blocks the other end, then why the hole was machined so tight than one needs to hammer on the sleeve (installer rod) to press it into the hole? Why not machine the hole a little larger so the sleeve can be installed easier but with no obvious backlash or clearance. This would make sleeve removal an easy task.

Pic below shows the installed sleeves have no step, as we can see the sleeve bottom is protruding into the BH. If it is a tight fit, then it is better to install the sleeve this deep as it has less chance for the pin to cock eye and lock up.
Last is the sleeve orientation. Do people align the sleeve seam line to a particular position or just random? I would align the sleeve seam line to the same side as the pin ramp face. This leaves the sleeve smooth bearing surface for the pin to slide against when the ball bearing riding on the pin ramp, less chance of lock up on a rougher surface. Maybe the sleeve seam line should be 90* away form the pin ramp face is the best choice.

[George Hill]

sapote can you provide any instance of someone having a bushing move in the bore?

I thought you were worried about the sleeve getting loose in the bore? Why would you then suggest to make the bore bigger? If you tear up the bore removing the bushing either in a way that there is permanent damage then A. you shouldn't be working on it or B. you shouldn't be working on it. Yes you can get them out without damaging the bore. And yes, sometimes the bore gets a nick in it which is nothing a file to the high spots won't fix. You are way over thinking this and creating solutions for problems that don't exist.

As far as bushing depth, you are suggesting to install the bushing as pictured. Again this is a solution looking for a problem. The issue I SEE with that idea is that when the pin is pressed in there will be part of the bushing that is not in contact with any part of the pin (because of its chamfer). Also keep in mind the pin is longer than the bushing so the further out of the bore you push the bushing the closer the pin is to being unsupported on the other end. BUT AGAIN, these are not issues with the design, follow what BMWs lead and everything is fine.

[sapote]

sapote can you provide any instance of someone having a bushing move in the bore?

Hi George,
I have not see a case of the sleeve moved into the tranny, but the pic that I reposted maybe an example: both sleeves have moved in but they were stopped going further whenever the roller pushing the detent pin in. Obviously we will not see the sleeve completely fell inside the tranny as the pin stopper blocks it off, and the ball bearing roller will push it back, when shifting gear. Also majority of tranny have the step in the bore, and so it’s hard to find a case for this.

I thought you were worried about the sleeve getting loose in the bore? Why would you then suggest to make the bore bigger?

My question is why the sleeve is pressed in too tight in the bore that requires to fold it inward in order to remove it – I’m just curious? Isn’t it better not to have the sleeve too tight in the bore as there is a step and the sealing cap at two ends to prevent it from moving?
We know it is a fact that the pin can seize inside the sleeve for some reasons. You have repaired many cases like this, but I bet all or most of them are factory sleeves with the step in the bore. Imagine if the pin seized in the sleeve, and there is no step in the bore, then what can happen? I think the compressed spring will push the sleeve in.

If you tear up the bore removing the bushing either in a way that there is permanent damage then A. you shouldn't be working on it or B. you shouldn't be working on it. Yes you can get them out without damaging the bore. And yes, sometimes the bore gets a nick in it which is nothing a file to the high spots won't fix. You are way over thinking this and creating solutions for problems that don't exist.

How do you remove the sleeve without damaging the bore? All video I have seen people used an awl to fold the sleeve inward and the process caused scores on the aluminum bore. Here are some examples:
From FCP, starts at 12:30, he hammer in the awl between the sleeve and the bore wall to fold the sleeve in. Imagine the scratches on the bore.
https://www.google.com/search?q=bmw+...idSDALWoO_LQ

Another one from a Pro who is much better than the FCP guy above. Look at 9:29, the damage on the bore:
https://www.google.com/search?q=bmw+...id:ITBP-_a9sZY

As far as bushing depth, you are suggesting to install the bushing as pictured. Again this is a solution looking for a problem. The issue I SEE with that idea is that when the pin is pressed in there will be part of the bushing that is not in contact with any part of the pin (because of its chamfer). Also keep in mind the pin is longer than the bushing so the further out of the bore you push the bushing the closer the pin is to being unsupported on the other end. BUT AGAIN, these are not issues with the design, follow what BMWs lead and everything is fine.

These are not issues with the design, but we do see the pin seized inside the sleeve, don’t we? And we all like to know why the pin seized in the sleeve, and what can we do to avoid that. I’m not suggest to have the sleeve protruding too far beyond the BH wall, but if people choose to have no step in the bore, then why not press the sleeve in so it is about 2mm (or where the roller sweep through) beyond the BH inner wall to support the pin better? Why I think it is better? When the bearing roller rides on the pin chamfer, it pushes the pin in against the spring, and it also push the pin against the sleeve wall by the same spring force (45* force vector), and this force is max at the BH inner wall whereas the pin force on the sleeve is minimum near the sealing cap. The further the sleeve end away from the pin chamfer, the more cantilever force on the pin without support, and this places a larger force on the sleeve end. Therefore, to minimize the wear on the sleeve and pin, the sleeve should be located at the force vector opposite of the pin chamfer, not at the other end near the sealing cap.
The wear on the sleeve at opposite of the pin chamfer is the main reason why the pin locked up (due to rough bearing surface) and the shifter cannot push it in to select the gears.

[George Hill]

I have not see a case of the sleeve moved into the tranny, but the pic that I reposted maybe an example: both sleeves have moved in but they were stopped going further whenever the roller pushing the detent pin in.

Those bushings did not move to that location on their own, that is 100% how they were installed.

ZF5 transmissions don't have this step and they don't have any issues with the bushing "moving" once installed even when the pin starts to stick.

As I said in my first post the ZF5 does NOT have the step and the bushings do NOT "fall into" the transmission on their own even though they 100% can go inside the trans unlike the 420g BH.

My question is why the sleeve is pressed in too tight in the bore that requires to fold it inward in order to remove it – I’m just curious? Isn’t it better not to have the sleeve too tight in the bore as there is a step and the sealing cap at two ends to prevent it from moving?

The cap does not but up against the bushing, the spring force pushes the cap outwards and is held in place with the circlip, it does not contact the bushing.

We know it is a fact that the pin can seize inside the sleeve for some reasons. You have repaired many cases like this, but I bet all or most of them are factory sleeves with the step in the bore. Imagine if the pin seized in the sleeve, and there is no step in the bore, then what can happen? I think the compressed spring will push the sleeve in.

Has there ever been a documented case of a pin sticking in a 420g BH (6 or 8 cylinder)? I have not seen that, the issue that you are talking about is a ZF5 problem. As stated above they do not have a step in the bore and the bushings do not follow out when they stick.

How do you remove the sleeve without damaging the bore? All video I have seen people used an awl to fold the sleeve inward and the process caused scores on the aluminum bore. Here are some examples:
From FCP, starts at 12:30, he hammer in the awl between the sleeve and the bore wall to fold the sleeve in. Imagine the scratches on the bore.
https://www.google.com/search?q=bmw+...idSDALWoO_LQ

Another one from a Pro who is much better than the FCP guy above. Look at 9:29, the damage on the bore:
https://www.google.com/search?q=bmw+...id:ITBP-_a9sZY

I didn't watch those videos, but I've seen some shops use a slide hammer with a similar setup as to pull a pilot bearing. But yes you can do it with a an awl as you stated, sometimes the bore gets nicked, if so you just file the high spot down. It makes no difference in the operation.

These are not issues with the design, but we do see the pin seized inside the sleeve, don’t we?

No we don't /thread.

[sapote]

Those bushings did not move to that location on their own, that is 100% how they were installed.

Oh, so you worked on this box? These sleeves slightly protrude out which I theorized that this help to reduce the cantilever force from the pin on the sleeve to help reduce the wear, but you objected to having the sleeves installed too deep compared to the factory. I'm sure with the step in the bore, the factory installed sleeves are at least 2mm not deep as the ones in the pic.

[sapote]

Has there ever been a documented case of a pin sticking in a 420g BH (6 or 8 cylinder)? I have not seen that, the issue that you are talking about is a ZF5 problem

Have not seen on the 420G yet, but this 250G with the similar (or same) pins locked up. Don't know why the ZF5 have much more problem with the pins.

https://www.youtube.com/watch?v=oDnoNxf_h2U

[George Hill]

Oh, so you worked on this box? These sleeves slightly protrude out which I theorized that this help to reduce the cantilever force from the pin on the sleeve to help reduce the wear, but you objected to having the sleeves installed too deep compared to the factory. I'm sure with the step in the bore, the factory installed sleeves are at least 2mm not deep as the ones in the pic.

I did not work on that box, but I can tell you with near 100% certainty that what you continue to propose is not AN ACTUAL ISSUE in practice. If the bore is actually 18mm you will not have an issue with the pin sticking or the bushing getting loose. The pins sticking are NOT and issue with the 420g. Maybe the issue with ZF5s was the material of the original bushing, I don't know and frankly it doesn't matter in this situation. You are continuing to create a narrative that this is a problem. This is not beneficial to members who maybe aren't as knowledgeable and don't fully understand how the system works. And once again I feel like you are trolling me and I am falling for it. Again. LOL.