Diff ring gear bolts removed without using big vise?

[sapote]

I thought we had discussed this before, but I couldn't find the thread and so this new thread is created.

Looking at the pic, I think using a boxed wrench we could loosen the bolts while the diff still on the car, by pulling the handbrake hard to lock the drive shafts. Not everyone has a big vise bolted down on a sturdy work bench to hold the round carrier.

[sapote]

But this housing is slightly different, and the box wrench might not clear the wall:

[ZiMMie]

Pull it out from casing and use an impact wrench.

[sapote]

Pull it out from casing and use an impact wrench.

Then why the pros at Racing Diff used a big vise and a long breaker bar to loosen the bolts, then he used the power tool to get them out?

[ZiMMie]

why don't you ask the "pro"?

[sapote]

I believe impact wrench can weaken the bolts. It generated very high impulse torque, like hammering. If you don't reuse the bolts then impact tool is fine, but I won't use the tool if I want to reuse the bolts.

[ZiMMie]

Why would you go through all that to reuse the ring gear bolts?

they are cheap enough to replace.

[sapote]

Why would you go through all that to reuse the ring gear bolts?

they are cheap enough to replace.

Any reason not to reuse them? Don't like to trash good stuffs. Where do you get them new as I don't see them on RealOEM?

[Mspir3d]

As tight as some of those bolts were, I’d hate to loosen them in the car with a wrench. It took some serious torque to break a few of them loose. I bought a vise from the hardware store and installed it on a makeshift table. Then used my foot to keep it from moving when I broke them loose. I didn’t want to install the vise on my nice workbench but It’s been pretty handy several times since then.

[sapote]

Yes, these bolts were torqued to around 110 ft-lbs (based on Racing Diff video), but the hand brake -- drive shaft -- output flange -- side gear -- spiders -- carrier should be able to handle this easily as we all know the system is capable of burning the tires.

[sapote]

I was looking at the E46 M3 Torque Spec in the Tech Section but couldn't find the ring gear bolts torque spec. But I found this pic. interesting: in the back ground is a Porsche 901 dog-leg transaxle that I'm very familiar with -- I have a few spare and had converted one from 4 speed to 5-speeed, and changed a few gears to suite my FWY commuting. Is this from TIS or from a member here?

[paulclaude]

Rather than roughly clamping the LSD unit in a vice, i welded up a specific jig for this job so the bolts can be correctly removed and torqued. I wouldn't recommend an impact gun if re-using the bolts as mentioned.

[Arith2]

From what I could find the bolts are M14s and the torque is either 162 ftlbs or 177 ftlbs. I think non M bolts are different but I have not had a BMW diff apart yet to confirm. I'm still searching but this is somewhere to start.

[sapote]

Rather than roughly clamping the LSD unit in a vice, i welded up a specific jig for this job so the bolts can be correctly removed and torqued. I wouldn't recommend an impact gun if re-using the bolts as mentioned.

Excellent idea, but why not just have a plate with 3 holes: the big center hole to clear the side-gear boss, and two outer holes to clear the bolts? This plate alone is much stronger than having the 2 "prong" bolted to the plate working as the stoppers.

[paulclaude]

Excellent idea, but why not just have a plate with 3 holes: the big center hole to clear the side-gear boss, and two outer holes to clear the bolts? This plate alone is much stronger than having the 2 "prong" bolted to the plate working as the stoppers.

I'm sure that would work as well, however, a flat plate wouldn't have too much material in the center area if the carrier bearing is still in place so may be a little weak - with this design I can bolt down the bar assembly and the two location sockets and it holds everything solid with no issues removing or applying torque to the bolts