What went wrong with rear diff bushing install? Pic attached

[mapster37]

That picture looks like they trimmed/cut material from the bushing to install (aka hack)
Look for a different shop to continue work on your vehicle.

[M3SQRD]

Originally Posted by janseny7

That’s why I didn’t fight him too much about messing up the poly bushing. I couldn’t say with 100% certainty that both updated OEM poly bushings would fit.

Based on Track/s’s pictures in the other thread, it appears the oem left and oem right bushings are different colors. Are the two bushings the same or different colors?
https://f80.bimmerpost.com/forums/sh...69&postcount=2

[theweebabySeamus]

Older and/or original bushing darkens over time and a new one is the color of the one on the right.

[M3SQRD]

Originally Posted by theweebabySeamus

Older and/or original bushing darkens over time and a new one is the color of the one on the right.

I haven’t swapped diff bushings yet so I did not know. Thanks!

[hC1001]

damn, that bushing is hacked up... What the heck happened...

[spidy512]

Oh man.

That is aweful. They clearly didn't use the proper tool. Or any tool.

(edit: as others have pointed out) Here is a link to an aftermarket updated bushing tool that is similar to the OEM tool I think.

https://www.mlperformance.co/product...3-m4-mw90541-t

It basically tapers down, squishing the bushing properly into the subframe (special lube is def needed). Properly installed, the bushing is crushed into the subframe compressing/stiffening the foam up just enough to be stiff and quiet at the same time. Its kinda of a cool design.

I debated these bushings vs poly and ended up going with poly and a duall bushing plate. It was hands down one of the best mods I did to the car. The upgraded bushing is a good upgrade, but I loved the poly and plate. The car is *so* much more planted.

FWIW, the poly bushing install is easier, so maybe that is a good idea for this shop to use to get the car out of there...

good luck!

josh

[Track/S]

Originally Posted by hC1001

Maybe they didnt lube it for installation?

Correct way to install is to lube the diff carrier bushing hole and bushing with circolight. Its a temporary lube that is slippery when wet but dries and becomes no longer slippery. Its suppose to be pressed in from the rear towards the front. The bushing orientation is correct in the pic. The flatter side with part#s are suppose to be seen from rear of car.

I can only speculate the bushing got damaged during pressing in because there was no lube used. It looks like pieces of the sides got caught and ripped off and is stuck between the bushing and diff hole wall causing the left side to roll back.

Originally Posted by hC1001

I also wanted to add that the BMW instructions also say the poly bushings shouldnt be used on your car. They only recommend the rubber one on all cars before 7/2016. Anything after will need to check what rear subframe is installed on the car. So BMW used different subframes over the years and they specifically mention compatibility issues with specific subframes. I know a lot of ppl have installed the poly ones on earlier cars without issues but no one ever mentions BMW instructions on the compatibility of the subframes. Im guessing it might have to do with the carbon fiber driveshaft switch to steel. Maybe the poly bushing caused more NVH, i dunno. I went with powerflex so i cant comment if its fine to use the poly one on earlier F8X cars.

This is from the TIS:

Note:
For vehicles up to 07/18, the rubber mount with the BMW part number 7 852 495 is to be installed in connection with the rear axle support 2 284 640. Only the rubber mount with BMW part number 7 852 495 may be used for vehicles up to 07/16.

For vehicles from 07/2018, the polyurethane rubber mount with the BMW part number 8 094 690 is to be installed in connection with the rear axle support with the BMW part number 8 097 478. The polyurethane rubber mount with BMW part number 8 094 690 is used as a replacement from 07/16.

Before removing and installing the rubber mount, check which variant is or will be installed!

In this thread is the answer to the OP's question


https://f80.bimmerpost.com/forums/sh....php?t=2101512


The latest f80 used a metal driveshaft with a poly bushing, and I have not seen a difference between a subframe with a rubber bushing vs a poly bushing, poly can be installed in both and same with rubber












Poly bushings on subframe with rubber one

[Track/S]

Originally Posted by theweebabySeamus

Older and/or original bushing darkens over time and a new one is the color of the one on the right.

Originally Posted by M3SQRD

I haven’t swapped diff bushings yet so I did not know. Thanks!

No, it does not turn black over time, the black poly has part number 8094690 and was replaced with yellow with PN 9503009

[janseny7]

Just wanted to say thanks everyone for their help. Gave this Beamer Indy shop a chance but won’t be going back. They are good people, no malice or were trying to trick me.

They just didn’t know how to properly do a poly bushing. I couldn’t fight them too much on it because technically it wasn’t the original part and I wasn’t 100% certain that upgraded bushing would fit. Even though I’ve read posts that the poly bushing retro fits.