///M E86/5 rear diff bush replacement

Jembo · Post by **Jembo** » Mon Jun 05, 2023 2:47 pm

I am gobsmacked having had these replaced today.

Made a real noticeable difference to the way it drives, especially under load.

IMO almost on the same level as fitting RTAB’s & RTAL’s

Despite the £200 plus VAT having them fitted, was worth every penny

TheDan · Post by **TheDan** » Mon Jun 05, 2023 3:00 pm

Ooooh interesting, I want to get mine done soon. Was this the rearmost bush on the differential? Or did you get all 3 replaced? £200 + VAT is actually not bad for this job, where did you get it done?

Jembo · Post by **Jembo** » Mon Jun 05, 2023 3:06 pm

ETA, details of this plus bushes

rocket70 · Post by **rocket70** » Mon Jun 05, 2023 7:05 pm

What were the symptoms as to why you got them changed?

inkey$ · Post by **inkey$** » Mon Jun 05, 2023 7:28 pm

Sounds like a result, Jem.

beanie · Post by **beanie** » Mon Jun 05, 2023 8:22 pm

I’d be curious to know if you get any diff whine from them. Forum ‘wisdom’ suggests anything other than an OE rubber bush will give you varying degrees of whine as speeds increase but a real world opinion on this platform would be great.

I assume it’s these you had fitted?

https://www.ecstuning.com/b-ecs-parts/c ... 47ecs03kt/

Car looks great btw, such a good colour Sepang

Jembo · Post by **Jembo** » Tue Jun 06, 2023 7:43 am

rocket70 wrote: ↑Mon Jun 05, 2023 7:05 pm What were the symptoms as to why you got them changed?

Intermittent transmission shake

Jembo · Post by **Jembo** » Tue Jun 06, 2023 7:52 am

beanie wrote: ↑Mon Jun 05, 2023 8:22 pm I’d be curious to know if you get any diff whine from them. Forum ‘wisdom’ suggests anything other than an OE rubber bush will give you varying degrees of whine as speeds increase but a real world opinion on this platform would be great.

I assume it’s these you had fitted?

https://www.ecstuning.com/b-ecs-parts/c ... 47ecs03kt/

Car looks great btw, such a good colour Sepang

:

Car has always whined like a touring car, thought this was an undocumented feature of every ///M

Bush invoice pic is above in thread if helps.

Spriteracer · Post by **Spriteracer** » Tue Jun 06, 2023 9:31 am

On the whining point... When I got my car (non M E86) the subframe and diff bushes were shot and my indy suggested using poly all round. I'm not sure if it is the bushes but I've had some whine ever since. Thought it was the diff, although only done 75K at that point and changed it for the E85 auto version of the same ratio. It still whines, so I'm assuming it is the poly bushes passing through much more harshness and noise from the diff into the shell. I now have all the parts to change back to oem and a full set of new bearings for the original diff. Work and racing rather got in the way but planning to change back to fully oem later this summer in the hope it will restore peace and tranquillity to the back end!

beanie · Post by **beanie** » Tue Jun 06, 2023 9:44 am

Jembo wrote: ↑Tue Jun 06, 2023 7:52 am Car has always whined like a touring car, thought this was an undocumented feature of every ///M

Bush invoice pic is above in thread if helps.

Mine doesn’t make any noise at all, well, not in terms of diff whine. Of course, now I’ve said that I’m sure things will change

Our Z3 sounds like a touring car but that’s done 220,000km

Jembo · Post by **Jembo** » Tue Jun 06, 2023 10:11 am

beanie wrote: ↑Tue Jun 06, 2023 9:44 am
Jembo wrote: ↑Tue Jun 06, 2023 7:52 am Car has always whined like a touring car, thought this was an undocumented feature of every ///M

Bush invoice pic is above in thread if helps.
Mine doesn’t make any noise at all, well, not in terms of diff whine. Of course, now I’ve said that I’m sure things will change Our Z3 sounds like a touring car but that’s done 220,000km

You need a Gruppe induction kit then

If you’re ever down South, be good to compare.

Wassup · Post by **Wassup** » Tue Jun 06, 2023 5:10 pm

The ECS tuning rear differential bush kit is fantastic from what I hear too. I've had a set fitted to my rebuilt differential, just got to get it fitted to the car in the coming weeks.

: IMG_20230120_135646.jpg (189.43 KiB) Viewed 417 times

There's also a customs and handling fee to be mindful of when ordering from the States, goes without saying but not shown in the sales invoice above.

Jembo · Post by **Jembo** » Tue Jun 06, 2023 5:31 pm

Wassup wrote: ↑Tue Jun 06, 2023 5:10 pm There's also a customs and handling fee to be mindful of when ordering from the States, goes without saying but not shown in the sales invoice above.

I’m still waiting for the present from HMRC.

Not wishing to tempt fate, these arrived back in February 23 & I still haven’t received anything … so don’t tell anyone.

beanie · Post by **beanie** » Wed Jun 07, 2023 10:05 am

Jembo wrote: ↑Tue Jun 06, 2023 10:11 am
You need a Gruppe induction kit then

If you’re ever down South, be good to compare.

I think I’ll pass on the Gruppe

: 1ECA6CF0-4ADF-4EA1-B100-0802DD58CD67.jpeg (193.41 KiB) Viewed 380 times

Jembo · Post by **Jembo** » Wed Jun 07, 2023 10:30 am

Z4-forum.com

Z4-forum.com