Ultimate Rear Diff Bushings DIY

[NORAGRETS]

I’m replacing the galvanized ones with grade 5 titanium

[Cleveralias]

Thanks very much for taking the time to document this job!

I just completed it on my car and wanted to add one thing for others planning to swap their bushings: I was able to get the 4 bushings out of the front mount without removing it from the car, saving the work of having to disconnect and support the driveshaft/trans. There’s enough room to manipulate and press those bushings while the mount is on the driveshaft.

Still a big job, but skipping that step makes it slightly less so.

[elsixto]

Hello, thank you for your contribution, I have a question. Does doing this completely eliminate the hum/vibration during hard acceleration especially uphill and in 3rd, 4th or 5th gear?

[MetzgerMeister]

Absolutely superb write-up and video Samf82m4

I'm going the cheaper route and only replacing the stock bushing with a purple Powerflex one. Any chance you could advise on the steps I need to take here? I'm not installing the dual bushing mount or doing the bushes on the front of the diff.

Cheers!

[BB123]

Thanks for the great writeup and video Samf82m4. I managed to successfully tackle this last weekend without needing to disconnect the driveshaft as shown in this video (referenced from the Powerflex site):

Some other pointers to share:
- This bearing press/pull tool worked great for both the rear and forward bushings: https://www.amazon.com/gp/product/B07BH22YCR (you'll want to make sure you have a couple 22mm wrenches)
- The 4x forward bushings are 49.5mm in diameter
- The rear bushing is 67.5mm in diameter as per theweebabySeamus: https://f80.bimmerpost.com/forums/sh...80&postcount=7
- In addition to the tools/sockets listed, you'll need an 18mm socket
- The strut mounting bolts seemed to be ~21ft lbs (I couldn't find a spec so I measured them)
- The caliper mounting bolts are 81ft lbs

ben

[MetzgerMeister]

Any truth to the rumour that if you're only doing the rear bush you can just lower the subframe on the bolts?

[Zernen]

My next project. Thanks for the write up.

[BB123]

Originally Posted by MetzgerMeister

Any truth to the rumour that if you're only doing the rear bush you can just lower the subframe on the bolts?

Hmm, maybe... the reason for dropping the subframe lower than the service bolts allow is to access the driver side front bracket bolt, but I'm not sure how easy it'd be to pull/cut-out the rear bush without getting the diff out of the way (which does require removing the front bracket).

Tbh, removing the caliper and strut bolts really isn't a big deal, you just need to make sure you have 2 jacks on hand (one for the subframe and one for the diff).

And while you're at it, may as well replace the front bushings too... Some posts were advising against having 2 different types of bushings so I played it safe and replaced them all – it really is just incremental work compared to everything you're doing to get access to the rear bush.

ben

[MetzgerMeister]

Originally Posted by BB123

Hmm, maybe... the reason for dropping the subframe lower than the service bolts allow is to access the driver side front bracket bolt, but I'm not sure how easy it'd be to pull/cut-out the rear bush without getting the diff out of the way (which does require removing the front bracket).

Tbh, removing the caliper and strut bolts really isn't a big deal, you just need to make sure you have 2 jacks on hand (one for the subframe and one for the diff).

And while you're at it, may as well replace the front bushings too... Some posts were advising against having 2 different types of bushings so I played it safe and replaced them all – it really is just incremental work compared to everything you're doing to get access to the rear bush.

ben

Some posts are indeed advising against 2 different types of bushings but isn't that exactly what BMW are doing by only replacing the 1 rear bushing and leaving the front ones?

The main reason I'm only doing the rear one is because I don't want to fork out the cash for the front ones given that in all cases they're in perfect shape.

I do have 2 low-entry jacks so all good on that front!