Z4 Differential Cover Install (Not DIY)

I just replaced my the differential cover with a cover from a Z4 while I installed a Quaife LSD. This is not a DIY for the procedure. However, I did want to point out two items that are required for a proper install that I didn't know about when I ordered my cover.

The Z4 cover is a direct bolt on for non-M3 E46 differentials. However, you need to purchase two additional items: 1)Loctite 5970 Gasket Maker, and 2)one 60mm diff bolt (M10X60-8.8-ZNS up to 9/03 build or M10X60-10.9ZNS3 from 9/03)

You won't find diff gaskets any more; BMW uses the loctite in lieu of a gasket. The loctite is difficult to find outside of BMW dealerships, but it is out there. BMW charges about $45 a tube. Off the shelf products will not resist gear oil the way the loctite product does; the diff will leak after awhile.

Although you can reuse the bolts from your old diff, the Z4 cover requires one bolt that is longer than the others.

what are the advantages of the z4 diff cover?

Originally Posted by kaotek323i

what are the advantages of the z4 diff cover?

Also ... Can you write a short review on the lsd ? did you feel any improvement?

Thanks for sharing

Just so you know, the run of the mill loctite silicone sealant will work for the diff. For example, the ultra-black will be suffice. For any of you old timers, Permatex Aviation form-a-gasket is excellent (Indian Head Shellac works too) is a cheap alternative.

FYI: Red loctite all of the diff cover bolts if you track your car and run solid bushings. This is a great way to reduce your maintenance time between events (I use a bunch of red loctite on my cars).

Originally Posted by lkstaack

I just replaced my the differential cover with a cover from a Z4 while I installed a Quaife LSD. This is not a DIY for the procedure. However, I did want to point out two items that are required for a proper install that I didn't know about when I ordered my cover.

The Z4 cover is a direct bolt on for non-M3 E46 differentials. However, you need to purchase two additional items: 1)Loctite 5970 Gasket Maker, and 2)one 60mm diff bolt (M10X60-8.8-ZNS up to 9/03 build or M10X60-10.9ZNS3 from 9/03)

Thread resurrection here, but I've just purchased a LSD an awaiting it arrival. I plan on installing the Z4 finned diff cover, my car is a pre 03 model so i will be buying the M10x60-8.8-ZNS version of the long bolt. However for the remaining 7 bolts will i need my E46 bolts or the equivalent Z4 bolts for models up to 09/2003?

For those interested and wondering why install the z4 cover, the fins help keep the diff oil cooler and thus better protection for the diff itself. E46's didnt have diff fins.

i used autozone permatex. 5 months later and zero leaks. i also used a oem gasket that i was able to find from a member on here so i used both

i have non lsd 3.46 with finned diff cover. it look awesome under there

Looks like this stuff could be safely used as an alternative to the pricey loctite 5970 stuff:

http://www.permatex.com/products/pro...t-maker-detail

Permatex part number 81182

Also the BMW part number for the longer bolt is 07119905148

Originally Posted by kaotek323i

what are the advantages of the z4 diff cover?

It finned so it keep oil cooler

Originally Posted by kaotek323i

what are the advantages of the z4 diff cover?

The E46 Motorsports Finned cover is avail as a BMW Motorsports part; slightly different casting than the Z4 unit. Same effect also and avail brand new from BMW

The Higher capacity of oil compared to standard cover is nice for thermal stress as well; the cover is also heavier and stiffer/stronger (more metal)






BMW Motorsports cover (NEW):



Z4 finned cover (used)



Casting difference at bolt mounting: the required length of bolts are different!

BMW Motorsports cover

Z4 finned cover