Rear end clunk SI B33 04 09/08

E86montego · Post by **E86montego** » Fri Oct 21, 2016 4:22 pm

Hi all,

Everybody is (I presume) very bored of this topic by now. However I post for two reasons:

1) Because this service bulletin is very hard to find now, I've posted it below for anyone who needs it.

2) I'd like to get mine done, but not happy to pay £350 through BMW. Are there any decent BMW specialists/ indys around the West Midlands who have done this to anybody elses car?

Really would appreciate the help on this, thank you in advance!

GuidoK · Post by **GuidoK** » Fri Oct 21, 2016 6:27 pm

Do you have this clunk?
This repair is not without risk as the diff input flange has to come off.
If the nut of the flange is not screwed back in exactly the same position or overtightened, the crimp bus inside can alter the pretention on the pinion shaft bearings.
Normally you completely disassemble the diff and feel with your hand if the pretention on those bearings is good. You cant do that on the car.

Fox889 · Post by **Fox889** » Fri Oct 21, 2016 6:33 pm

Just had mine done, you don't need an Indie just a good garage with a lift/hoist.
Worst problem was the exhaust, apart from that very straight forward.
If you look at my thread from a couple of weeks ago, there's a piece on there how to do it, very simple.
The flange literally fell off, as there's no grease on the splines it's purely metal to metal.
Whole job from start to finish should be between 4 & 6 hours [bearing in mind this was the first time he'd done this + those pesky exhaust nuts!].

Have fun, btw, it's cured the clunk!!!!!

GuidoK · Post by **GuidoK** » Fri Oct 21, 2016 9:13 pm

^ so what kind of grease did you use? the bmw grease or generic high pressure grease?
And did you apply it only on the flange mating surface or also on the splines?

Fox889 · Post by **Fox889** » Sat Oct 22, 2016 8:32 am

Believe it or not, Loctite 648
If you search on here for Diff Input Flange Greasing M54 Engine (3.0) - Z4-forum.com
Below is the BMW service bulletin as well.
It doesn't have to be loctite, heavy duty grease will do but Loctite 648 [eBay item number:161859342163] is apparently made for this type of job where metal meets metal, it's only happened because the original BMW grease has washed away over time causing the splines to go metal to metal, hence your click or clunk.

SI B33 04 08
Rear Axle
August 2009
Technical Service
This Service Information bulletin supersedes SI B33 04 09 dated October 2008.
[NEW] designates changes to this revision
The differential input flange mating surface with the input drive pinion is insufficiently greased.
E82 and E88 (1 Series), all models
E85 and E86 (Z4), all models
E60 and E61 (5 Series), all models
E63 and E64 (6 Series), all models
E65 and E66 (7 Series), all models
E90, E91, E92 and E93 (3 Series), all models
The customer complains that a single cracking or clicking noise can be heard from the rear of the vehicle while engaging a drive gear, releasing the clutch, during load reversal (shifting from reverse to drive, etc.), or when accelerating from a stationary position.
This is not a failure of the differential assembly. Do not replace the complete differential.
Remove the differential drive flange in accordance with Repair Instruction RA 33 11 021. Apply lubricant [NEW] P/N 83 23 0 443 864 on the input flange mating surface (1), as described in the illustration.
Before complete reassembly. replace the input flange seal and collar nut retaining plate as described in RA 33 01 021. Refer to the EPC for correct part numbers, based on model.
/ message sig

GuidoK · Post by **GuidoK** » Sat Oct 22, 2016 12:57 pm

you think you can still get your flange off? The loctite does 30N/mm² according to their specs.
If I calculate that if the shaft (the splined section) would be 2cm in diamter, 2,5cm long and the splines would multiply the area by 1,5; you'd need 7tonnes (7000kg) of pulling power to get it off. (I dont know the exact dimension of the splined axle by heart, but it needs quite a force to get it off again)