E36 Differential Issues... pictures included

[Michael. 2312]

So I had my diff ratio changed from 3.15 to 4.27 by Neil Allport Motorsports. They charged me $460 to set the gears correctly for 5 hours labour which I was somewhat shocked at.

They replaced the front pinion seal only and reused the old bearings which they said were 'ok'

I had to however source the side output seals, for some reason they didn't do this.

All seemed well. I refitted the diff and ran the car, noticing straight away it had a faint whine at speed noticeable from after 60kph, a vibration seemed to occur at 120kph of which I felt was diff related. The whine would be most noticable on and off with light throttle.

I asked the Neil Allport guy I dealt with, Here is our brief conversation:

Me: " I seem to be getting a subtle diff whine which gets more noticeable as the speed increases...Not an alarming noise, but noticable, whether its LSD related or tired bearings?Could also be wheel bearings but I will need to investigate further I think!

Them: "With second hand running gear in the diff, it could have been noisy when you brought it? but it's def related to the gear inside the diff, not the way it's been built.. "

So that was about 2000kms ago and it's got no better if not worse.

I decided to remove my diff last night and put the stock one back in.

To my surprised the front pinion seal has been leaking, flicking oil all over the exhaust and surrounding areas... the bottom of the subframe was dripping with diff oil.

After removing it, I removed the oil which was now dark brown with metallic swirls throughout, and 500ml is gone, filled it to 1.7L and now its down to 1.2L

Heres some pictures of the oil and gear teeth. Originally this gear set was bought in good used condition, having centered wear marks on the drive and cost sides of the teeth.

Tell me what you experts think!

No transparency with about 200ml of oil under light..

Upon putting my old open diff back in it feels like a different car, quieter and much smoother, no vibrations.

[B.M.W Ltd 950]

Give me a call

[Ahmedsinc 414]

Would be very interested to hear the outcome of this. The oil you drained looked slightly worse than the fluid that was in my 3.73 after I completed the manual conversion. 170000km on what I assume was the factory oil, certainly no indication it had ever been changed

[allan 295]

If you haven't googled yet maybe this might help

https://www.google.co.nz/search?q=diff+tooth+contact+pattern&newwindow=1&hl=en-NZ&tbm=isch&tbo=u&source=univ&sa=X&ei=qM5gU_f6G4j6lAXNpIHgAQ&ved=0CDYQsAQ&biw=1426&bih=766.

Also would like to know the out come of this situation.

[euroriffic 603]

That's not good! Mate an I did the centre swap from open to lsd centre with no such issues like this and we are idiots hahaha

[Ahmedsinc 414]

That's not good! Mate an I did the centre swap from open to lsd centre with no such issues like this and we are idiots hahaha

Ditto, ratio change is a whole different story though. Have to get the preload and lash absolutely perfect otherwise it'll lunch itself sooner or later. Looking to swap a 3.46 gearset into my 3.73 to see if I like it better shortly (currently running 3.15 LSD but feel the torque loss is too significant), was chatting to an engineer mate of mine & he talked me through the process. Certainly nothing to take lightly, I had a headache by the time he finished explaining it

[thorburn 120]

Do you have a dti gauge?

[thorburn 120]

if your interested in seeing hat they should of been doing in those 5 hours read here http://ohiobimmers.com/forum/showthread.php?t=3624 you'll need to register sadly

[Ahmedsinc 414]

if your interested in seeing hat they should of been doing in those 5 hours read here http://ohiobimmers.com/forum/showthread.php?t=3624 you'll need to register sadly

Probably one of the most informative threads I've seen in ages. Unfortunately for me it scuttles my plan to use the 3.64 gearset in my E36. OP in the ohio thread discovered E39 pinion shafts are an inch shorter than E36 ones Gut instinct tells me it's not viable to mix and match pinions to crowns to create a different ratio. Boo!

[Beeker2 69]

Go see Kayne Barrie, he seems to be the goto expert on BMW diffs and gearbox's.

PS. Neil Allport has a good reputation over a long period of time, but typically in jappa 4wd rally or old school rally, as opposed to Euro.

Edited May 3, 2014 by Beeker2

[KBM 5]

This is all very interesting....

Kayne Barrie Here, this is my area of things, if you want my help by all means ring, my only comment on the above is, $460 is not much for that job to be done properly, as someone else has said, that it is critical to get the set up right or it will be noisy and wear prematurely .

If you had/have contacted me about this job, was I too expensive? just curious because I get a lot of referral for this and wondered what you consider to be a reasonable price for this (to be done once;)

[///MPROVD 131]

When I swapped my center I didnt replace anything just a 3.15 open swapped lsd it cost 150 for pitch the to be set has been working perfect