Premature CSB Failure

[dinanm3atl]

Was driving the M52/ZF E30 around today. Took off from a light with moderate gas and get the old CSB rumble under my seat. That is odd. Low mile driveshaft and brand new CSB and Guibo were installed when the motor went in. This sucks.

Now I know the reasons for this failing earlier. Have I missed anything? Driveshaft out of balance or u-joints seized. Does the CSB have a short lifespan when installed backwards(as seems to be correct for my setup?).

Any other ideas? Thought?

M52
ZF
Late 328i/M3 Driveshaft w/ E30 CSB Backwards

I am going to drop all the exhaust. Make sure it isn't loose(I doubt it). Guess drop it out and get a fresh installed along with balance and confirm driveshaft is true. Is running it backwards also necessary? I don't think a few thousand miles is normal for a 24V car to need a CSB.

After 4K in 1st and anywhere else... no CSB rumble...

[sharky]

Did you preload it when installing it? I installed mine the correct way (not backwards) and preloaded it and have had no problems.

[dinanm3atl]

Yah.

E30 CSB on an E36 drive with a ZF trans? If it doesn't have to be backwards I don't want to put it backwards.

[jeffw]

i didn't preload mine when i put it on (i forgot lol) and didn't have a problem with it. If the u joints aren't seized and the driveshaft is balanced check your guibo. feels similar but you may have the guibo on wrong or it may be trashed

[dinanm3atl]

Guibo was replaced brand new. I made this post before full diagnosis so I can get a feel for the problem on a 24V car. It just suddenly started. It wasn't sort of there and then really bad. I am leaning on and hoping it somehow loosened up. 1st gear is the onyl gear it happens. Between 2-4K. After that... nothing. Smooth like normal.

I'll report back.

[jeffw]

well if its smooth after 1st then i am guessing something is loose just like youre thinking. just start in second lol

[cabin]

I am running S50/ZF. When I first installed the DS, I put the CSB on backwards, and it gave a slight angle to the DS. I now have it on the correct way and the DS is much straighter than before. Not sure if it was like this in your case, but it would be sure to have caused premature failure if I had left it like that on mine. Good luck getting the issue solved, be sure to report back.

[JGood]

Definitely check the guibo nuts and bolts. Did you reuse them, or are they new?

[dinanm3atl]

They were 100% fresh on the Guibo. All new hardware.

Tuesday I am dropping down exhaust and heat shields. This car was 100% apart at one point. Nothing is stock or was not removed. My diff loosened up and was giving me noise. Tightened up all the bolts. Same deal on my RTABs and the bushings making noise.

I wouldn't doubt the guibo, CSB or something else has loosened up a bit.

[etxxz]

if its a low frequency thing i would look at the u-joints like something is binded. The csb is bearing my experience with not preloading is chattering when you lift. normally a bad csb loose and/or bad balance drivehsaft vibrates at any speed with frequency increasing/relative with speed. What are your transmission mount and does the car vibrate in idle/low rpm? (can be at standstill for this question)

[dinanm3atl]

Trans mounts are UUC + Cups brand new.
Guibo is brand new with new hardware.
CSB is brand new. Nuts re-used.
DS was used. Low miles I was told.

As said I will check everything other on Tuesday it looks like.

[lifeiskaos]

Edited, new info found

FWIW, I believe that the CSB needs to be installed forwards, just as stock. Here is a picture of my setup.



That CSB is offset towards the passenger's side. If it were installed backwards, the driveshaft would be angled even more than you see there.

[etxxz]

the reason i asked aobut the tranny mounts was because i've had terrible vibration on poly mounts. stock rubber ones do it for me.

[lifeiskaos]

the reason i asked aobut the tranny mounts was because i've had terrible vibration on poly mounts. stock rubber ones do it for me.

+1. I use stock rubber with AKG transmission mount cups and it's more than solid for DD or even track use IMO, and WAY more comfortable

[JGood]

FWIW, I believe that the CSB needs to be backwards. I assume that because the engine is rotated 15 degrees compared to an m20, it slightly moves the centerline of the crank. Here is a picture of my setup, with a backwards CSB:



That CSB is offset towards the passenger's side. If it were installed forwards, the driveshaft would be angled even more than you see there.

You are the first person I've come across other then myself who has the driveshaft angle like that. FYI, that CSB is installed correctly, in the same orientation as stock.