heavy vibration in shifter after changing guibo and shift linkage bushings

[docterelliott]

just replaced my guibo, centering sleeve, tranny mounts(added some caps), center support bearing, and shift linkage refresh kit. took it out for the first drive. hard vibration in the shifter in 1st. 2nd was worse and now it felt like the drive shaft was actually touching the shifter! I could feel and hear something vibrating and scraping against the shifter. the sound and feeling got worse during acceleration. then 2nd gear popped out. I have no idea what it could be. everything looked great as it went back together any ideas?

[bmwdirtracer]

When a center support bearing dies, it is because the u-joint in the driveshaft is bad, and replacing just the center support bearing won't fix that - you need a new driveshaft.

Worse than that is if you didn't MARK the two halves of the driveshaft, and return them to their EXACT orientation with one another, because the driveshaft is balanced AS A UNIT. If you've done this, the driveshaft MUST be rebalanced on a driveshaft balancing machine.

The vibration will also be worse, because you "added caps" to the trans mounts, which would reduce the isolation built into the rubber mounts. And, um, did you preload the center support 5mm forward?

[docterelliott]

Its not so much the vibration that is the issue...its that the shifter and or shifter rod is touching the guibo or some part of the driveshaft. Its only when i shift to second that it feels like its rubbing. Ive never read anything saying to replace the u-joint when replacing the csb. I pushed the drive shaft forward when i tightened the csb bracket per pelicans diy as well as marked the ds halves. I may have been one pline tooth off but that shouldnt cause the driveshaft to be so off aligned as to touch the shift linkage.

[bladerealm124]

Its not so much the vibration that is the issue...its that the shifter and or shifter rod is touching the guibo or some part of the driveshaft. Its only when i shift to second that it feels like its rubbing. Ive never read anything saying to replace the u-joint when replacing the csb. I pushed the drive shaft forward when i tightened the csb bracket per pelicans diy as well as marked the ds halves. I may have been one pline tooth off but that shouldnt cause the driveshaft to be so off aligned as to touch the shift linkage.

I had this exact same issue from a ripped csb. It was almost exclusive to second gear and then slowly transferred to other gears as the csb got worse. But second was always the worst. Felt like a horrible grinding coming up through the floor board and shifter that increased with rpms but was the worst between 1500-3000. Very loud as well. Not sure why you would have this issue since you say you just replaced yours but it sounds like symptoms of a blown csb

[docterelliott]

yes sounds exactly like that! hopefully thats all it is then. keep you posted. thanks!!

[bmwdirtracer]

I'm going to try this one more time, because removing driveshafts is no fun, if you don't fix the problem.

When the driveshaft is off, rotate the u-joint gently through both of its movements; left right, and up down. You will feel a notch in the movement, This is because the u-joint operates at a specific angle, all its life, and wears at that particular point, creating a sloppy, binding movement. This destroys the center support.

While I've known pro BMW techs to replace just the center support, I don't know any that do so more than once, because the customer's always pissed off a month or so later, when the vibration reappears. And shame on Pelican Parts for not stating this in their DIY.

If the guibo is touching your shift linkage, you've done something very wrong. Likely, the rear of the shifter carrier is not in the bushing.

[docterelliott]

figured out what it was....and I feel like a dummie. the shift connector rod that attaches the shifter to the transmission is slightly bent to account for the guibo...well I put that in upside down so the bend was facing down:/ oops. while I was under there I doubled checked the csb pre-load and its good. also tried to remount the UUC tranny mount caps on the top of the tranny mounts like Ive seen in all the pix of them but thanks to the alignment knotches, my mounts will only fit one way and those caps are only meant to fit one way with the mounts so on the bottom they stayed.

took the M3 for a test drive and all is well now! woohoo. I will pay attention to the vibrations to see if it comes back in a month or so. If it does I guess I'll know to replace the u-Joint. It would be very helpful if the companies we bought these parts from would warn us about these kind of repair "need-to-knows". anyways, thanks for all the help!!

[bmwdirtracer]

Forgot about that one; it's been quite a few years since I made that mistake - but rest assured, I've made that mistake...you won't repeat it ever again, neither will I.

Be aware that the u-joint is a "non-replaceable" item. Certainly, some people have "hacked" the replacement, and not rebalanced the unit, even one guy who used jb weld to rig the spacing. And I'll hope I'm not in or behind that car when it all comes loose..... Meanwhile, for my own car, or for any customer's or friends, I will insist on a rebuilt and rebalanced driveshaft from a good BMW driveshaft specialist. For whatever reason, there seem to be a disproportionate number of these places in Portland, Oregon, pretty close to you.