Change Subframe Bushings while Swapping Diff?

[LSB4Me]

Hey Everyone:

It is finally time for my 3.91 swap and looking to tackle any “while I’m in there” items.

While the diff is coming out, does it make sense to swap my subframe bushings for CMP Solids?

TIA.

[EthanolTurbo]

Hey Everyone:

It is finally time for my 3.91 swap and looking to tackle any “while I’m in there” items.

While the diff is coming out, does it make sense to swap my subframe bushings for CMP Solids?

TIA.

Yes. And maybe do a Vincebar or other additional reinforcement while you're in there.

[oceansize]

Hey Everyone:

It is finally time for my 3.91 swap and looking to tackle any “while I’m in there” items.

While the diff is coming out, does it make sense to swap my subframe bushings for CMP Solids?

TIA.

If you're lowered then yes. If you're not lowered don't use the CMPs.

[George Hill]

Hey Everyone:

It is finally time for my 3.91 swap and looking to tackle any “while I’m in there” items.

While the diff is coming out, does it make sense to swap my subframe bushings for CMP Solids?

TIA.

If you are just swapping the diff, then no I would not say it makes sense to do it "while you are in there." BUT if you are going to lower the rear subframe then yes.

I would say it makes more sense to replace the upper and lower control arm inner bushings if you have the diff out.

[LSB4Me]

Yes. And maybe do a Vincebar or other additional reinforcement while you're in there.

Thanks, I'll look at Vincebarring.

If you're lowered then yes. If you're not lowered don't use the CMPs.

Definitely lowered (Ohlins), so CMP seems like the move.

If you are just swapping the diff, then no I would not say it makes sense to do it "while you are in there." BUT if you are going to lower the rear subframe then yes.

I would say it makes more sense to replace the upper and lower control arm inner bushings if you have the diff out.

Appreciate it, George. It doesn't sound like there's a big duplication of efforts (read: labor crossover) between subframe bushings and diff swap, so I might hold off unless you/others say otherwise. My fear was that the diff had to come out to get at the subframe bushings. In which case, it would be best to do them during the 3.91 swap.

I do believe my rear control arm bushings have been done already, so I'm in the clear there.

[George Hill]

Appreciate it, George. It doesn't sound like there's a big duplication of efforts (read: labor crossover) between subframe bushings and diff swap, so I might hold off unless you/others say otherwise. My fear was that the diff had to come out to get at the subframe bushings. In which case, it would be best to do them during the 3.91 swap.

I do believe my rear control arm bushings have been done already, so I'm in the clear there.

*To clarify I WOULD replace the front diff bushing in the subframe.
*The subframe bushings to chassis are not affected in anyway by the diff being installed (or not).
*You CAN get the inner control arm bolts out with the diff in the car but its a terrible experience and the repair instructions say the diff should be out. I would highly consider these if you don't know for sure they've been done. IF you are going to replace them then measure the cars ride height before disassembly. After replacing both bushings/arms and without the diff, coil springs and shock installed jack up the hub to simulate the ride height and torque the inner bolts.

[bigjae46]

If you are just swapping the diff, then no I would not say it makes sense to do it "while you are in there." BUT if you are going to lower the rear subframe then yes.

I would say it makes more sense to replace the upper and lower control arm inner bushings if you have the diff out.

The lower control arm bolts are so infuriating. It’s literally just a couple of mm’s from being able to get it out. 😡

Isn’t there a tool that allows on car replacement of the subframe bushings?

[old///MFanatic]

I would agree with subframe bushings are not a “while you’re in there” thing.
If anything I would replace the front differential bushing and rear diff cover/bushings “while in there”. And for these bushings I feel the factory ones are plenty good. Depending on your use it’s not always an upgrade to go firmer or poly here. Even if they do sound like it’s sportier-sexier.
Also, if you’re doing the diff install yourself. I can’t say how often the mistake is made with cross stripping that front diff bolt. So clean it and pay extra attention during install.

[heinzboehmer]

Also, if you’re doing the diff install yourself. I can’t say how often the mistake is made with cross stripping that front diff bolt. So clean it and pay extra attention during install.

100% this. Clean both the bolt and the threads in the diff and follow the install sequence from TIS:

[LSB4Me]

100% this. Clean both the bolt and the threads in the diff and follow the install sequence from TIS:

Thanks, guys. I’m putting on a new diff cover and installing a new front bushing, though the shop is doing the work + install. Stock rubber in both places. I was planning to flag the fragility of the front bushing, but will pass on the TIS for good measure. Appreciate that.

And, to round out the thread, it sounds like subframe bushings don’t make sense at the same time, so I won’t bother. My bushings were changed when the subframe was reinforced. Stock rubber there as well.