LSD vent?

[JFENG]

How Important is it to have a vent on your LSD?

E24's had of them E9's did not.

 

[OCCoupe]

The e9 has a vent at the top of the differential. I believe the vent helped with overfilling. At high speeds too much oil could equate to frothing and then less viscosity.

#7 on Realoem

http://www.realoem.com/bmw/enUS/showparts?id=7031-EUR-09-1973-E9-BMW-30CSi&diagId=33_0915

 

[JFENG]

Is that why the e24 diff had the external reservoir? To catch and return the excess fluid when it got really hot?

I have a side loader out of an early e24 (maybe I should call it an e12 based six series) with a missing external reservoir and plumbing. I was hoping to cheap out and not buy these parts from the dealer.

 

[OCCoupe]

It's my understanding that the canister was used on the e12 m535i and the early e12 chassis m635. Both used the 3.07 side-loader differential and the canister that you are missing. The canister was there to catch any vapor that might occur at higher speeds. I don't think the canister is really all that necessary especially at the speeds we drive in the US compared to Germany's Autobahn.

I hope someone chimes in; but I think you will be ok using the vent cap that is normally used on these differentials and a drain plug where the return line would go.

 

[JFENG]

Guys
Ok. I can jusy cap and plug or put a nipple in the $18 cap and a line to a small catch can. Either way saves me $1xx.

Thanks guys.

 

[deQuincey]

for informative purposes only...

 

[JFENG]

Beautiful, and worthy of envy!

I believe all of these are still available via the dealer (?).
But, if I don't need them then I will put the money toward something else like a short shift kit.
John