Its not my tires

[saxguy09]

I never said this shaft was any better...

[jlevie]

yes, so claims the company, the 1st shaft I had to send back because of a balance issue, would DS balance be speed specific? vibration is only between 60-80 mph

If you had to send one drive shaft back because of a balance issue, what makes you think that this one is any better?

The only rebuilt drive shaft that I'll use is one from Driveline Services. It is either that or a new OEM unit.

[saxguy09]

OK, had another look at the engine mounts. the passenger side mount is pushed out quite a bit, the rubber isnt broken just weak. Maybe this may cause a small misalignment? who knows. lol

[saxguy09]

I preloaded it....such thing as "over pre-loading"?

[KVF]

If the vibration truly goes away at 80+ I'd think it's not a DS balance issue... Does it go away or does it merely lessen?

The bolts on the guibo do not have to line up with the arrows, but should all be uniform. As you indicated, just make sure the arrows on the guibo point toward the respective flange.

While I have never heard anyone else discuss it, the Bentley seems to place a good deal of emphasis in properly pre-loading the CSB. Failing to do so will apparently lead to excessive vibration over 35mph.

[saxguy09]

yes, so claims the company, the 1st shaft I had to send back because of a balance issue, would DS balance be speed specific? vibration is only between 60-80 mph

[KVF]

Was the shaft actually balanced when it was rebuilt?

[saxguy09]

yes. its on the money, went by both paint dabs and u-joints. I did order new motor mounts because i am freshening everything up so maybe it might help if the old ones are worn

[jlevie]

Its a rebuilt shaft and all other parts are new. The wheels are borbet h's but i didnt have this vibration previously.

Have you double checked to be sure the drive shaft is assembled with the paint marks matched up?

[saxguy09]

Also I found it strange to get rid of the 40mph vibration by orienting the flex disc bolts all in the same direction, maybe i will put the bolts on according to the arrows and see what happens..

[saxguy09]

Its a rebuilt shaft and all other parts are new. The wheels are borbet h's but i didnt have this vibration previously.

[jlevie]

It doesn't matter which way the bolts are oriented. But it does matter that the drive shaft halves be correctly assembled in the orientation that the drive shaft was balanced (matched paint marks).

When you say "second new driveshaft, csb, and flex disc" are you talking about salvage yard parts or a new or rebuilt drive shaft? In the former case the vibration could be from a bad drive shaft, but that isn't likely in the latter case.

Are the wheels stock or made specifically for an E30? Use of wheels that have no hubcentric ring or wheels whose hubcentric ring isn't a close sliding fit on the hub can result in wheels that can't be balanced off the car.

[saxguy09]

Ok so shortly after installing my second new driveshaft, csb, and flex disc, i noticed a small wobble at around 40 mph. Had a friend check it out and he told me that the bolts in the flex disc should all go in toward the transmission. After flipping the bolts around, I now have a massage-like vibration at 60-70mph. I had my tires balanced changed wheels all that jazz, vibration is still there. Do the flex disc bolts need to go in with the direction of the arrows that also point toward the flanges?