M10/E12 conrod bolt troubles

[Keith_MN]

Rod bearing job, using new OEM M10 bolts. Got cylinder 1 done and had some trouble with the E12 heads deforming more than expected on the final 105* sweep. On cylinder 6 now, torque sequence #2 and I'm pretty sure sequence #3 is not going to be successful. The heads are too fucked already. I'm using a 1/2" breaker bar with an analog angle gauge. I have two E12 sockets of different brands, both are (or were) new, both look to be in good shape still. Car is on jackstands, doing this on my back. Subframe not removed but dropped and out of the way.

Didn't see much on a quick search so just wondering. Am I doing something wrong? Others had this issue? At this rate I'm considering switching to ARP. At a minimum I'll need to replace the two in cylinder #6.

[jayjaya29]

Even on a lift I have mangled a number of M10 bolts. I buy extras. I've found that cleaning the head of the bolt and the inside of the socket with brake clean so they are dry helps.

[karter16]

When I did this on jack stands many years ago I found it simply wasn't a 1 person job - here's an excerpt from my journal of how we did this:

" We then moved on to doing the rod bearings... To begin with it was actually an absolute mission. It just isn't possible for a single person to manage 105 degrees of angle torque when lying under the car (in our experience anyway). We burned through a couple of spare bolts practicing, and trying different approaches, but we just couldn't make it work. 70 degrees would have been fine, so I can understand how this would have worked for the older E46's, but we just couldn't reliably pull 105 degrees in a single stroke.

After some trial and error, and a fair amount of frustration on my part we came up with an approach that worked.

It takes 3 people, but it's a reliable approach. Basically the tool is as follows:
Bit -> Angle gauge -> 12 in extension -> long breaker bar -> breaker bar extension (pipe).

Person #1: Holds the bit, gauge, extension assembly in the right place, cradling the angle between the extension and the breaker bar against their shoulder. They're responsible for maintaining the tool on axis as person #3 rotates the assembly.

Person #2: Their sole job is to locate the gauge and call out progress to Person #3.

Person #3: Rotates the tool through 105 degrees.

Person #1 & #2 are underneath the car. Person #3 is near the front left wheel well.

It's important before each pull that you check that you have 105 degrees of motion available to you. We found that if we got it wrong we would collide with the front left jack stand.

This approach made the tightening procedure fairly straightforward and reproducible."

[Keith_MN]

Thanks all, making me feel better.

Was definitely thinking it would be easier with two people to ensure the correct engagement to the bolt and leverage on the breaker.

Figures I just ordered from FCP on Fri. Will get a few spares ordered and move on to other tasks in the interim.

[Slideways]

The head of the wrench needs to have hand pressure applied to it to keep the socket from slipping while swinging the wrench 105 degrees. Best to avoid extensions if possible. With a good E12 torx socket (Craftsman worked well), it should not deform the head of the bolt.

[Cubieman]

Even on a lift with a 1/2" techangle it can be difficult, I have done 6 or 7 E6x M cars and one E46 M3 solo, I forget what the angle comes out to be in ft lbs, but it felt like a lot.

I remember wanting someone to hold the tool tight to the bolt even with the advantage of a lift, on jacks stands I would definitely want some help.

[George Hill]

Just did a set yesterday, its roughly 88N-m +/-

Doing them on your back I would pull the subframe. I've done maybe 100+ with the subframe still in place and when I was younger that was no big deal. Getting older its harder to swing the ratchet and hold pressure on the head of the ratchet and maneuver around the subframe.

I have found that if you can muscle it that a shorter ratchet helps as you have less leverage trying to move the head of the ratchet off center. It also makes it easier to swing if you have the suspension in place as there is less interference being shorter.

[Keith_MN]

Appreciate the advice!

My E12 sockets are 3/8ths which likely isn't helping. Have a 1/2" on the way. Quality tbd, but worth a shot to get rid of the 3/8ths adapter.

[George Hill]

***Additionally I have a Snap-On socket that is waaaay tighter fitting than my Silver Eagle (Matco budget line). I use the SE on my ratchet to break everything loose and have the SO on my torque wrench. Both 3/8" I've generally preferred some extension so a 1/2-3/8 adapter isn't an issue.

Now that we are talking about it I wonder if my SO socket is getting tired. Its the same one thats been in use since at least 2008. It's probably taken loose thousands of bolts and I'm wondering if it has some wear now. I might buy a new SO and Matco and see if I can find a better fit. ***I assume the SE is just a looser socket because of its price point.

[bigjae46]

Remove the subframe. Makes life easier and you are more likely to do higher quality work.

I used an analog angle gauge once. A 1/2" digital torque wrench is much easier.

[samthejam]

I used an angle gauge that George Hill recommended. He has done so many of these, and his recommendation definitely showed it. This tool was fantastic. I've used other lesser angle gauges but this one is the real deal, made this already stressful job less stressful.
https://www.amazon.com/dp/B003QHFTIM?ref_=ppx_hzsearch_conn_dt_b_fed_asin_ti tle_7&th=1

Used a half inch breaker bar and this guy. I just bought extra bolts and if anything at all went weird in the process. I went and grabbed new bolts and redid both sides. I bough about 6 extras iirc.


I don't trust the electronic torque wrenches unless it's a very high dollar one and I am familiar with it. I have seen cases where the angle reading didn't calculate right and no bueno.

[D-O]

I used both 3/8" and 1/2" techangles depending on which rod and what the clearance was like. I still needed 4 extra bolts to get it done properly.

I can't imagine doing it without removing the subframe.

[1000hp]

As harped-on in the other thread, highly recommend ditching the analog angle gauge and spending the money on a quality digital angle torque wrench.

That eliminates an akward tool between you and the bolts. The second I started to round one of my M11 bolts I stopped and sought out the right tool.

I believe the ISTA instructions were written before there was a commonly available digital angle wrench. I don't see a logical reason to use the old school tool, (other than the high cost of the new tool).

[cobra]

I did mine with subframe off and didn't have any issues. It was definitely a workout but totally doable with regular tools.

I used an analog dial gauge because there is no question it's accurate.

[George Hill]

I don't see a logical reason to use the old school tool, (other than the high cost of the new tool).

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....