1995 BMW 840ci needs help

[Yellowjacket]

A quick background: My differential started making a rumbling/howling sound and I know the differential will need replacing this year. The discounted price at Tischer for the part is $1800.

I got some excellent feedback on the forum for places to build the part. Dan at www.diffonline.com quoted $995 if open and $1295 if limited slip which is a significant saving from retail cost. My challenge now is my trusty mechanic does not have space to park a diff-less car for 2 weeks during rebuilt. I do not have a garage or driveway. I am reaching out to see if anyone in the club who may have the space and ability to help me with this project. I can pay $250 for the trouble of storage and help, my elbow grease and slight mechanical knowledge. Thanks. Moses, Cheverly, MD

[kimokk]

Moses,

You should bring your car to the next DIY session. You just missed one today.

[Yellowjacket]

The car will not be drivable with the differential.removed.

[kimokk]

The car will not be drivable with the differential.removed.

Have it towed to the next session then.

[Yellowjacket]

@kkimokk: You are misunderstanding the situation. The car is drivable currently. Thanks for your input, but I am discussing this issue with experienced techs on this forum.

[gkrea1]

I've replaced the differential in my E32 which, mechanically, is very similar to your E31. Instead of rebuilding it, I just bought a used one. It cost about $300 for a 3.91 limited slip unit. I cleaned and installed it in one day. Depending on how you use your car (you're not tracking it, I assume) this may be the best route for you. I volunteer at most of the DIY days and could help out.

I bought my car with 124k on it. It is possible a previous owner neglected to chage the diff oil at the proper interval. Is this a possibility with your car? I ask because it seems that worn out differentials are rare with our generation BMWs.

[rrsperry]

If downtime is a big deal, just buy a rebuilt diff from Dan and pay the refundable core charge. He'll ship you a rebuilt diff built to your specs and you just send him the old one when you install it. He refunds the core charge. Presto, limited downtime.

[Yellowjacket]

Thanks for the recommendations. Metric and Diff Online do not have one in stock. I wish I could do a swap. My local mechanic can handle it for a reasonable price. The other models may have similar innards but the case is different. BTW Dan's price is really good ($1k for an open).

[rrsperry]

If it were me, I'd have him rebuild it with a 40% lsd... But that's just me.

[Yellowjacket]

If it were me, I'd have him rebuild it with a 40% lsd... But that's just me.

You beat me to my own thoughts. If I can work out the logistics of parking my car and removing the diff, I will get LSD for ~$350 more.

[pseto]

thought i'd share this from the National website for all 8 series owners:

http://bmwcca.org/forum/showthread.php?t=6979

[kimokk]

@kkimokk: You are misunderstanding the situation. The car is drivable currently. Thanks for your input, but I am discussing this issue with experienced techs on this forum.

If your car is still drivable then I guess you should be able to buy a rebuilt one and swap it out at one of the DIY events? Or am I missing something?

[Ahmed303]

You may want to check with the guys of this group.

DC Metro E31 Special Interest Group