M10/E12 conrod bolt troubles

[Keith_MN]

just break the angle into 2 more manageable chunks rather than a single angle

I felt like this was a big reason why I liked the Stahlwille gauge. If I needed to, I could reliably hold my mark and reposition for the rest of the angle.

[karter16]

just break the angle into 2 more manageable chunks rather than a single angle

Strictly speaking the "angle" part of torquing a TTY bolt is supposed to be done in a single continuous motion. In fact if memory serves me correctly I believe that is called out in the TIS procedure.


Edit: memory does serve me correctly:

[digger]

Strictly speaking the "angle" part of torquing a TTY bolt is supposed to be done in a single continuous motion. In fact if memory serves me correctly I believe that is called out in the TIS procedure.


Edit: memory does serve me correctly:

it makes insignificant difference with an angle method (no matter what the TIS says) it is not the same as tensioning to a torque value where you want to make sure don't creep up to the last bit of the torque value. So if you are having issues following that is what i would do. if 60 degrees is the biggest jump you can comfortable to then end with that amount. If we were talking about a manned mission to mars then sure be pedantic

[bigjae46]

it makes insignificant difference with an angle method (no matter what the TIS says) it is not the same as tensioning to a torque value where you want to make sure don't creep up to the last bit of the torque value. So if you are having issues following that is what i would do. if 60 degrees is the biggest jump you can comfortable to then end with that amount. If we were talking about a manned mission to mars then sure be pedantic

If all these people keep swapping S54s into bullshit cars then yes, we will be talking about something like a manned mission to mars lol

I kid...no one get offended.

[George Hill]

I think its more so because asking some random tech to divide 105* into (2) swings is asking for trouble. Additionally there is some spring in the tooling and it just increases the chance of an improper torque if done in multiple swings. I do 2x swings often, never been a problem yet.

[bigjae46]

I think its more so because asking some random tech to divide 105* into (2) swings is asking for trouble. Additionally there is some spring in the tooling and it just increases the chance of an improper torque if done in multiple swings. I do 2x swings often, never been a problem yet.

I bet BMW's TIS in asia says torque to 105 degrees, can use multiple pulls adding up to 105 degrees. lolololol

[D-O]

How many people are actually verifying their digital torque wrench is accurate (I bought a used SnapOn TechAngle for this exact reason) and it is off as much as 11* vs my analog....

An entirely valid point. I purchased both of mine brand new specifically for this job and trusted that the manufacturing QC would be sufficient. I considered purchasing them used and getting them calibrated, but they hold their value well enough that new was not too much more than used and calibrated.

I have heard that they will remain very accurate as long as they are not abused (over torqued, dropped, etc). Can anyone confirm this?

In any case, what is a good rule of thumb for how frequently they should be calibrated?

D-O

[digger]

I think its more so because asking some random tech to divide 105* into (2) swings is asking for trouble. Additionally there is some spring in the tooling and it just increases the chance of an improper torque if done in multiple swings. I do 2x swings often, never been a problem yet.

yes, one must still be sensible and pragmatic about it. If the design is that micro sensitive to procedure then you really shouldn't be installing them in situ in the first place.

[1000hp]

I think its more so because asking some random tech to divide 105* into (2) swings is asking for trouble. Additionally there is some spring in the tooling and it just increases the chance of an improper torque if done in multiple swings. I do 2x swings often, never been a problem yet.

Not much faith in the working class, eh? I think we should give professional technicians the benefit of the doubt on their ability to break 105 into two pieces. Sheesh.

Also, friendly reminder that your friend the digital angle torque wrench will keep track of the angle over as many pulls as you're inclined to make. And it doesn't require two separate human beings.
There should be minimal spring in the tooling as long as you aren't using worn out sockets, multiple adapters, or an undersized extension (e.g., 6" 3/8 extension when pulling a big angle like this one) .

[George Hill]

yes, one must still be sensible and pragmatic about it. If the design is that micro sensitive to procedure then you really shouldn't be installing them in situ in the first place.

I really wonder how sensitive the torque actually is, that would be a cool science project but IDK how you would quantify it.

Not much faith in the working class, eh? I think we should give professional technicians the benefit of the doubt on their ability to break 105 into two pieces. Sheesh.

You don't know me, and that's totally fine, but I was a dealer tech during the rod bearing recall days. I've done a lot, 75, maybe 100+ back then. The recall SIB/instructions (as posted above) were written 12/2004 which, 21 years ago we didn't have digital angle torque wrenches so those guys (me included) were doing them with an analog gauge as noted in the SIB which is made by Stahlwille. Even to this day I still use it. But when you are doing this work for time and you make that swing as far as you can go and think it says 70* and now you need to go 35* to hit your 105*. Then you think did it actually say 70* or did it say 60* and now I've only gone 95*. Or you are trying to make the full swing but only get 90*, its real hard to just do 15* Or you just did a set of the early bolts which go to 70* and you are doing that in 2 pulls 35* each, but your are on auto pilot on your late bolts and just did 35* and 55*. It happens, I've done it and had to throw some bolts away because I could remember if I got the right angle.

And I can 100% tell you that there were plenty of guys that went through the shop that had no business doing this repair, lol. And yes, I absolutely think some of them messed up the angle torque. Which is why I am curious to how much it can be "off" and still stay together. I personally do not recall a single M3 that came back with a blown engine after the recall was done, not even a suspicion of one.

Also, friendly reminder that your friend the digital angle torque wrench will keep track of the angle over as many pulls as you're inclined to make. And it doesn't require two separate human beings. There should be minimal spring in the tooling as long as you aren't using worn out sockets, multiple adapters, or an undersized extension (e.g., 6" 3/8 extension when pulling a big angle like this one) .

Best case scenario I agree with you, but the real world that isn't always that situation.

[Slideways]

I really wonder how sensitive the torque actually is, that would be a cool science project but IDK how you would quantify it.




You don't know me, and that's totally fine, but I was a dealer tech during the rod bearing recall days. I've done a lot, 75, maybe 100+ back then. The recall SIB/instructions (as posted above) were written 12/2004 which, 21 years ago we didn't have digital angle torque wrenches so those guys (me included) were doing them with an analog gauge as noted in the SIB which is made by Stahlwille. Even to this day I still use it. But when you are doing this work for time and you make that swing as far as you can go and think it says 70* and now you need to go 35* to hit your 105*. Then you think did it actually say 70* or did it say 60* and now I've only gone 95*. Or you are trying to make the full swing but only get 90*, its real hard to just do 15* Or you just did a set of the early bolts which go to 70* and you are doing that in 2 pulls 35* each, but your are on auto pilot on your late bolts and just did 35* and 55*. It happens, I've done it and had to throw some bolts away because I could remember if I got the right angle.

And I can 100% tell you that there were plenty of guys that went through the shop that had no business doing this repair, lol. And yes, I absolutely think some of them messed up the angle torque. Which is why I am curious to how much it can be "off" and still stay together. I personally do not recall a single M3 that came back with a blown engine after the recall was done, not even a suspicion of one.




Best case scenario I agree with you, but the real world that isn't always that situation.

I know someone on this forum that did it by eyeballing 105*. The car has done many miles and track days since.

I'd still follow the instructions to a T, and buy or borrow a digital wrench or angle gauge.

[digger]

I really wonder how sensitive the torque actually is, that would be a cool science project but IDK how you would quantify it.

You don't know me, and that's totally fine, but I was a dealer tech during the rod bearing recall days. I've done a lot, 75, maybe 100+ back then. The recall SIB/instructions (as posted above) were written 12/2004 which, 21 years ago we didn't have digital angle torque wrenches so those guys (me included) were doing them with an analog gauge as noted in the SIB which is made by Stahlwille. Even to this day I still use it. But when you are doing this work for time and you make that swing as far as you can go and think it says 70* and now you need to go 35* to hit your 105*. Then you think did it actually say 70* or did it say 60* and now I've only gone 95*. Or you are trying to make the full swing but only get 90*, its real hard to just do 15* Or you just did a set of the early bolts which go to 70* and you are doing that in 2 pulls 35* each, but your are on auto pilot on your late bolts and just did 35* and 55*. It happens, I've done it and had to throw some bolts away because I could remember if I got the right angle.

And I can 100% tell you that there were plenty of guys that went through the shop that had no business doing this repair, lol. And yes, I absolutely think some of them messed up the angle torque. Which is why I am curious to how much it can be "off" and still stay together. I personally do not recall a single M3 that came back with a blown engine after the recall was done, not even a suspicion of one.

Best case scenario I agree with you, but the real world that isn't always that situation.

There is how sensitive is the preload to the torque method, not that hard to bench test using a stretch gauge with ARP bolts. Structural standards i have used specify a large tolerance for example 1/2 turn +1/12,-0

Then more importantly there is how sensitive is the joint design to the preload you would need to do the sums using VDI 2230

[bigjae46]

Not much faith in the working class, eh? I think we should give professional technicians the benefit of the doubt on their ability to break 105 into two pieces. Sheesh.

There are excellent techs out there. I use a master tech in Houston that I'd go as far to say is probably the best one in Houston. I pay $125/hr for side job work...and it is worth it.

For that one top notch master tech, there are 5 village idiots and couple of shortcutters. I've seen some really stupid shit. The worst ones are the fast lane or oil change techs. They were porters/lot valets yesterday...changing the spark plugs on your car tomorrow. I've only seen one turn out to be a good tech. The others were generally lazy, dumb, or dishonest.

We should absolutely be skeptical of the quality of work being done in the automotive industry. Dealerships pay bottom dollar...they get bottom quality work. I would always tell techs...oh you start at $25 per flag hour? My mechanic in the oil/gas industry who worked on much simpler pumps, valves, gearboxes...started at $40/hr plus overtime plus travel. And that job is far simpler, although more consequential, than being an auto tech.

If you can make it as an industrial mechanic or I&E...you'd be a retard to work in automotive flagging hours.

[1000hp]

But when you are doing this work for time and you make that swing as far as you can go and think it says 70* and now you need to go 35* to hit your 105*. Then you think did it actually say 70* or did it say 60* and now I've only gone 95*. Or you are trying to make the full swing but only get 90*, its real hard to just do 15* Or you just did a set of the early bolts which go to 70* and you are doing that in 2 pulls 35* each, but your are on auto pilot on your late bolts and just did 35* and 55*. It happens, I've done it and had to throw some bolts away because I could remember if I got the right angle.

That's why I use a ratchet with the analog gauge. You might be off by a few degrees when you ratchet it, but you won't lose track and be off by 20 degrees.

For this job, though...laying on my back and trying to keep the socket nice and straight on an etorx bolt in a critical application, upside down, I'm not playing with the analog gauge at all.

[George Hill]

...not that hard to bench test using a stretch gauge with ARP bolts...

Great idea, next time I do a set I'll test the old ones. BMW says you can stretch them up to 5x times so a used set should give us 1-2 tests per bolt and maybe depending on what I find I'll get some new bolts and test too.