Rear Differential Cover.

[Suprgnat]

So I sent an email to Jim at Performance Gearing asking about the finned differential cover and spacer and whether I could buy it from him as a stand-alone option. I explained to him that I've already committed to purchasing from someone else (been talking to Dan at Diffsonline for over a month). Jim at PERFORMANCE GEARING http://performancegearing.com/ confirmed that the E60 finned diff cover P/N 33117516280 is the correct part number and generously gave me consent to share this information with the 1addicts community:

"Paul,

No, just an option for the complete rebuild.

That's the correct rear cover part number, you will need a longer rear mount bolt:

33 17 6 760 336

and a 15-16mm thick spacer , ID =14mm, OD= approx 32mm

or 3 of these:

33 17 6 779 816 (5mm thick aluminum spacers)"

[chris82]

Originally Posted by Suprgnat

So I sent an email to Jim at Performance Gearing asking about the finned differential cover and spacer and whether I could buy it from him as a stand-alone option. I explained to him that I've already committed to purchasing from someone else (been talking to Dan at Diffsonline for over a month). Jim at PERFORMANCE GEARING http://performancegearing.com/ confirmed that the E60 finned diff cover P/N 33117516280 is the correct part number and generously gave me consent to share this information with the 1addicts community:

"Paul,

No, just an option for the complete rebuild.

That's the correct rear cover part number, you will need a longer rear mount bolt:

33 17 6 760 336

and a 15-16mm thick spacer , ID =14mm, OD= approx 32mm

or 3 of these:

33 17 6 779 816 (5mm thick aluminum spacers)"

Awesome, thanks for sharing!

[Suprgnat]

Getting closer. Dan's saying the REM polishing has a two week lead time.

[Suprgnat]

So, reviewing innumerable posts it was obvious I'll need to machine the cover to clear the stock/BMWP exhaust. The Quaife/Birds cover is clearly a modified OEM BMW part and it looks to be machined on the last two fins about even to the thickness of the cover proper which is about 45mm. I've decided, after spending too much time under my car following getting back from a 16 hour delta-t, to machine as follows in the attached picture:

[Suprgnat]

Cover is ready, just waiting for the diff onto which to slap it.

[Bimmer-Bob]

Nice work!

Strange that you're cover needed machining - mine seems to be intact. I am, however, running the MagnaFlow cat-back - so maybe the dimensions are different enough from stock?

Anyway, glad you got it figured out. You're gonna love you're LSD!

[MightyMouseTech]

Now if somebody would only sell a damn cover with a drain bolt.

[Bimmer-Bob]

Originally Posted by MightyMouseTech

Now if somebody would only sell a damn cover with a drain bolt.

I think it's simple enough to extract the fluid from the fill plug with a pump. I had my diff fluid changed after break-in for 0.5 hours of labor. I mean, maybe they took the whole cover off in that time, not sure.

[MightyMouseTech]

Originally Posted by Bimmer-Bob

I think it's simple enough to extract the fluid from the fill plug with a pump. I had my diff fluid changed after break-in for 0.5 hours of labor. I mean, maybe they took the whole cover off in that time, not sure.

Except you can get out a lot more fluid with an actual drain.

And just to taunt us, was doing the diff fluids on my E90 XI, BMW can manage to put a drain plug on the front diff. Bastards.

[Bimmer-Bob]

Originally Posted by MightyMouseTech

Except you can get out a lot more fluid with an actual drain.

And just to taunt us, was doing the diff fluids on my E90 XI, BMW can manage to put a drain plug on the front diff. Bastards.

True. But wouldn't the drain plug have to be on the diff itself, and not on this cover (see image below)?

[MightyMouseTech]

Damn, wonder if we can use the 545 case?

[Bimmer-Bob]

Originally Posted by MightyMouseTech

Damn, wonder if we can use the 545 case?

Wish I had asked Jim about that when he was building my diff. I seem to recall someone saying that he built a diff for them with fill and drain plugs. At the time I placed my order, I just asked for the finned cover, thinking it had both plugs.

[Suprgnat]

Originally Posted by Bimmer-Bob

Nice work!

Strange that you're cover needed machining - mine seems to be intact. I am, however, running the MagnaFlow cat-back - so maybe the dimensions are different enough from stock?

Anyway, glad you got it figured out. You're gonna love you're LSD!

I noticed that the cover that TheSt|g got from Quaife had those fins machined off and I saw a couple of posts in E90post were those fins were either machined down or cut completely off. When I got back from my business trip the cover was waiting for me and I immediately climbed underneath my car and started taking measurements. Sure enough, there was no way those fins would have fit without interference.

I'd say you got lucky you have the MagnaFlow as if you had stock I think you'd have been in for a surprise.

I can't wait for the new diff! Dan said there was about a two week backlog on the REM polishing (which was a week ago), so I'm thinking I'm still 3 weeks out including shipping.

As an aside, I wish I had climbed under the car to check out the diff earlier. It turns out RealOEM has erroneous information and showed the 188 case as having the large 50mm nut like the 215 cases instead of the bolted flange. (The drive shaft illustration does show the 4 bolts correctly) Know anyone who needs a new 26117567770 nut and a couple of thin 50mm wrenches?

[houtan]

what did you use to shave off the fins?

[Suprgnat]

Originally Posted by houtan

what did you use to shave off the fins?

One of the machinists at work

[houtan]

Daym. I was hoping you were going to say dremel. Haha.

[Suprgnat]

Originally Posted by houtan

Daym. I was hoping you were going to say dremel. Haha.

Patience and a hacksaw/die grinder/dremel may work. IIRC a guy on E90post did it that way.

[Suprgnat]

This is my differential. There are many like it, but this one is mine.
My differential is my best friend. It is my life. I must master it as I must master my life. (Apologies to the USMC)

[asbrr]

Tasty, very tasty indeed.

Remind me, what kind of diff did you end up with? Can't remember with all the talk of the cover

[Suprgnat]

Originally Posted by asbrr

Tasty, very tasty indeed.

Remind me, what kind of diff did you end up with? Can't remember with all the talk of the cover

Diffsonline 3.64 3-clutch with 35/60 ramps and REM polished ring, pinion and bearings. Hopefully I'll get to install it tonight after work.

[Suprgnat]

In and done. OMG, OMG, OMG. I've only had a chance to do a shake down drive, but this is the single most transformative thing I've done to my car. Mad props to Dan at Diffsonline. Fantastic product, totally silent, IMHO perfect final drive ratio (3.64, still good to hit the 155MPH speed limiter in 6th given the opportunity) and the 35/60 ramps are totally smooth and predictable. Moderate lock on decel is sublime. Second photo shows clearance to the stock exhaust.

[Suhb]

How much did this run you? I want to redo my entire rear subframe (diff, bushings and bar) but I'm afraid I've got to fill the piggy bank a little more before I can.