Vibration on acceleration after LSD swap

[Firefight]

Hey guys just got around to getting rid of my auto 4.10 open diff in my touring and installed a 3.64lsd from a junk yard 735i

When I did the 5 speed swap I could use the rear drive shaft because it was to wide for my stock diff.
I held on to the rear half until I was able to get an lsd to put in there.

Today I started the swap. The car hasn't had any vibrations, all new components when I did the trans swap.

When it came time to swap rear drive shafts, I had a "great" idea and to save time I would just pull the snap ring and only swap the rear CV on the shaft. So I tore each apart and when I side the 5spd cv on the auto rear half the splines where about 3mm to short so the snap ring grove wasn't showing. Shit. So alright I will put it back on the correct shaft and as I pulled it off I dropped it 3 balls fell out, in the street and a bunch of dirt and little rocks got all in the inside of the cv.

So I tore it all down and cleaned the how thing out, slid it back in the shaft and reinstalled the bearing, then Packed grease, but the joint was really stiff and bearly moved.
finally got it all together and take it for a spin and I find that it shakes horribly on acceleration.
I drove it around and found that in neutral going down a big long hill, no vibration, if I'm under 2000rpm driving easy, can't really feel the vibration

My taught, I ruined the rear Cv when it fell apart or one of the u joints is blown.

My fear the new diff is garbage

Tomorrow I will crawl under it and double check everything is good and right but I would like some insight.
Thanks guys


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[Firefight]

I also looking back didn't preload the CSB, but I don't think that would cause this?


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[MehMan]

So I tore it all down and cleaned the how thing out, slid it back in the shaft and reinstalled the bearing, then Packed grease, but the joint was really stiff and bearly moved.

It's binding because you didn't put it back together correctly. It should move freely and smoothly. You probably offset the inner and outer cage.

[Firefight]

It's binding because you didn't put it back together correctly. It should move freely and smoothly. You probably offset the inner and outer cage.

Could that cause vibration

[moroza]

Yes. Also, an improperly preloaded CSB could cause that vibration, but if the CV is binding that's the main problem.

[Firefight]

Yes. Also, an improperly preloaded CSB could cause that vibration, but if the CV is binding that's the main problem.

Well I just went out and bought another rear half from the yard since the Cv alone is over $200 new. I'll be tossing that in and properly preload the CSB. Wish me luck, hope it's that and not somthing wrong with the diff.

Also side note I drove the touring to get the drive shaft and was on the free way, I don't think it's the diff because at 80mph no vibrations I could feel and I haven't heard a peep from the diff.

[moroza]

It's uncommon for diffs to vibrate unless they're missing pieces of gear or have *really* bad bearings, long before which you'll hear them howling and grinding.

[nonturbodan]

Definitely a driveshaft problem. No preload on the CSB would do it. Thats why you need to do it. If you don't preload it you will have issues.

[Firefight]

Cool thanks guys! I'm finally able to crawl under it tomorrow, gonna replace the csb and guibo as well as the rear shaft since I already bought it. Fingers crossed


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