Rear Driveshaft help

[Drewskiii]

hey new to r3v and need some help. I need to replace my rear driveshaft but have a few questions first. 1) I know there is no difference in driveshafts between auto and manny tranny, but is there a difference in lengths of the rear driveshafts between an ix coupe and an ix 4dr? (I have a 4 door) 2) If its not rusted to crap would it be smart to snag one off of an ix in a salvage/junk yard? or would it be smarter to find one on the interwebs (probably rebuilt)?


Thanks in advanced for your help

Drew

[nando]

all E30s are the same length (2 door, 4 door, touring, M3, convertable, etc)

good luck finding a used one. a rebuilt one is going to be around $500.

[Drewskiii]

hahahaha well then. I guess I'll start my search.

Thanks Nando

[z122643]

I just replaced my rear driveshaft. I got a rebuilt one for ~$600. The driveshaft is collapsable and can be extended or shortened to the right length. It is the same driveshaft for manual and auto.

So the bad news.
-If you get a salvage driveshaft you need to (without question!) take it to a shop to get it rebalanced. Otherwise it will vibrate like crazy. Also trying to match the position of the driveshaft on the salvage car to your car does not work. You need to get it rebalanced.
-The collar that lets you extend and collapse the driveshaft is a rust magnet. Only on CA, AZ and NV iX's have I seen rear driveshafts that could be re-used. On others, the collar is rust welded and will not move, and more than likely you will strip out the collar nut trying to get it off.

[nando]

there is no issue with matching a shaft to a different car. The shaft itself is balanced - there's a misconception that it was balanced on the car. however, if you accidentally pull the rear slip yoke from the rear of the shaft (the part that collapses) and put it together in a different position from what it was balanced, it would cause a problem.

how do you think that buying a new, balanced shaft and putting it in your car is any different from a used shaft (that was also balanced) and putting it in the same car?

also - WA/OR cars shouldn't have problems with rust on that collar nut. :)

[z122643]

I tried two salvage driveshafts in good condition. I was told that there would be no issue matching them. Instead the first one vibrated above 30mph and installation was not to blame. When I install the second one I also had vibrations but not nearly that bad.

I finally installed a rebuilt driveshaft and I have no vibrations. I had the second driveshaft rebalanced and was installed in a friends iX, no problems.

I do agree that there shouldn't need to be any balancing and it should work. Experience has shown otherwise. Now it is completely possible that the BMW gods just don't like me and the salvage driveshafts were bad. Though the cars I pulled them from were not crashed cars.

As a note to Drew, be careful not to pull the spines out (do not overextend the shaft)

[Drewskiii]

updaaaate



Alright probably not the smartest thing to do but my dad just cut that guy off after we got the driveshaft off of the car, otherwise I wouldn't be able to get it back on. I hope that won't cause any problems. I didn't really have any say in it hah, I was all for just getting another rear driveshaft but now I don't need one I guess.

Thanks for all the help by the way guys!

[z122643]

Did he cut it where the arrow is? If so, you need another shaft.

Nando what do you think?

[nando]

I tried two salvage driveshafts in good condition. I was told that there would be no issue matching them. Instead the first one vibrated above 30mph and installation was not to blame. When I install the second one I also had vibrations but not nearly that bad.

I finally installed a rebuilt driveshaft and I have no vibrations. I had the second driveshaft rebalanced and was installed in a friends iX, no problems.

I do agree that there shouldn't need to be any balancing and it should work. Experience has shown otherwise. Now it is completely possible that the BMW gods just don't like me and the salvage driveshafts were bad. Though the cars I pulled them from were not crashed cars.

As a note to Drew, be careful not to pull the spines out (do not overextend the shaft)

I'd bet the shafts were either bad or somebody had taken out the slip yoke and clocked it in the wrong position. they were out of balance before you ever got them in your car.

[nando]

I don't know why you'd cut that off. it's a dust shield for the splined section? I don't know if it will work without it but it will definitely be more prone to getting dirt/rust on the splines.

there's no problem pulling the splined section out of the shaft. You just have to be sure you put it back together with the same orientation. there should be a marking where the two peices line up.


wait - did you guys leave the slip yoke attatched to the car, and put a new DS on top of that? You can't do that, the slip yoke and shaft are a matched, balanced set. You've gauranteed a massive vibration. you need the slip yoke that came with your new shaft, and it has to be aligned in the same position it was originally balanced.

[Drewskiii]

I don't know why you'd cut that off. it's a dust shield for the splined section? I don't know if it will work without it but it will definitely be more prone to getting dirt/rust on the splines.

there's no problem pulling the splined section out of the shaft. You just have to be sure you put it back together with the same orientation. there should be a marking where the two peices line up.


wait - did you guys leave the slip yoke attatched to the car, and put a new DS on top of that? You can't do that, the slip yoke and shaft are a matched, balanced set. You've gauranteed a massive vibration. you need the slip yoke that came with your new shaft, and it has to be aligned in the same position it was originally balanced.

Yeah I know it's a dust cover but I also have read that it helps keep the nut snug and where it is supposed to be. So I don't know how long or if this is going to last. I'm going to try and pick up another one just in case my dad's "fix" ends up not working.