Replacement Driveshaft for my CS

[E9erCS]

I'm being offered a remanufacturered driveshaft for approximately one-half the cost of a new one from BMW. My old one has been removed, tested, and is out of balance, causing undue wear on the center support bearing as well as a noticeable vibration in the driveline.

Dare I risk a rebuilt one? Anyone have any experience in this realm?

Many thanks!

 

[x_atlas0]

I have had a good experience with my rebuilt one so far. I had it rebuilt when I switched over to a 5 speed.

 

[jmackro]

I guess it depends a little on a) WHY your current driveshaft has become imbalanced, and b) what the shop means by "rebuilt".

My first approach would be to simply have the old shaft balanced. All larger metropolitan areas have shops that work on driveshafts (I assume that heavy trucks are their primary market). If you old shaft has simply thrown off some of its balancing weights, these guys can figure out how to replace them.

Now, maybe when you wrote "rebuilt" you meant what I describe above. Or, perhaps there is a supplier in your area that has CS driveshafts on the shelf, already rebalanced, with new U joints installed, repainted, etc. That approach could be just as good as a factory replacement, though repairing your existing part is generally less expensive.

Unless your old one is really bent, rusted, or otherwise destroyed, buying a new factory replacement doesn't seem necessary.

 

[Bill Riblett]

BMW driveshafts have "U" joints which cannot be lubricated and which are not easily replaced. When the "U" joints get bad (grease goes away, rust, etc.) the joint no longer moves freely and the binding causes vibration. Replacement requires removing the old u-joint and precisely locating the new one which is staked in place.

There is something of an aftermarket industry which does this and they are usually pretty good. I did have to have a replacement in my 86 635 replaced under warranty after a couple of years, but mostly they seem to work pretty well.

Most local places are more used to American one-piece driveshafts and apparently don't always have the equipment to balance 2-piece driveshafts like BMWs have.

 

[bengal taiga]

Replacement driveshaft

At the risk of beating a dead driveshaft, any rebuild is only as good as the rebuilder and materials used. As with sparkplugs, fan clutches, oil alternators and even whole cars, all driveshafts are not manufactured equally well. If you can examine the finished part and it looks well re-manufactured, and the part comes from someone reputable or with a history of good products/service/opinions - you have done your best.

Although it happens infrequently, even newly manufactured parts don't always live up to their promises.