CSB replacement

[Varinn]

When I was doing my 5 speed swap in the summer I derped hard and didnt tighten the lock collar on the DS or preload the csb. I get vibrations through first, and on the highway. The driveshaft was butter smooth in my old e30 and the CSB was replaced during my swap so I figure it's just my own fuckup at fault, not worn ujoints. I'm doing a diff swap this weekend and I guess it's a good time to replace the center bearing while I've got access to a hoist for the day. I cant quite remember what needs to come apart to get at it though.

1: do I need to drop the exhaust? Or can I just loosen it off and sneak the heat shields out around it to get at the DS
2: how much force do I preload the new bearing with?

Edit: 1990 325i, 5spd and stock exhaust

[jlevie]

Lack of preload on the CSB or not tightening the collar nut isn't likely to cause the symptoms you describe. However they are a good match for binding u-joints in the drive shaft. Unless you see cracks in the rubber mount of the CSB, there is no need to replace it. If there are cracks, the cause will be binding u-joints in the drive shaft.

[red325ix]

I'm also trying to diagnose a similar issue but its proving a little difficult because I haven't had it on a lift yet. I'm getting a fairly pronounced vibration from underneath between about 45-60mph and I've ruled out rims, tires, and suspension. I think the PO had the driveshaft out and didn't reassemble it in proper balance.

I need to get it up on a lift and run it through the gears and see what I get I suppose.

[Varinn]

Shit, thanks for the input Jlevie. I'll look at it tomorrow but I'll worry about fixing it later, I'd rather just fix it right so I'll check the ujoints and plan for a repair later (even if it means a DS rebuild)

[bmwman91]

How does one pre-load the CSB exactly? Push it backward a little before bolting it in place so that it is pulling on the DS a little?

[jlevie]

You push the CSB forward to preload it.

[bmwman91]

Good to know, thanks. Sounds like I have another small project to take care of lol. If one does not do this, can you get varying degrees of DS-whip as a result? How far forward do you push it?