Damn Vibration

[vandan]

I have recently put in a Tom Wood multiple double cardan front shaft in my 02 WJ. Also, brand new motor, chrome moly axels with uni joints and an ARB locker (all in the front Dana 30).
I have now got this terrible vibration that starts at about 90kph and only while under acceleration. I have pulled out the front drive shaft and vibration dissappears. Had the shaft balanced and some pin replaced by driveline services at acacia ridge.
Re fitted the shaft and vibration just as bad as before.

Any Ideas? This is driving me friggen nuts.

[vandan]

I just inspected my brand new chrome moly axle uni joints and there is slight movement in both uni's in both directions. Apparently I can get bigger circlips for the caps does this sound like a fix?

[sssadamsss]

Im not too familiar with WJs suspension setup. but with double cardon drive shafts, the uni thats at the opposite end to the CV joint needs to be at 0 degrees. as in the pinion needs to be pointing directly up along the shaft.
do you have adjustable control arms?
In a TJ you would correct this problem with adjustable arms.

[vandan]

It's a "multiple" double cardan so it has a double cardan at both ends. But I do have adjustable long arms so I might try to take a bit of that angle out anyway.

[sssadamsss]

Hmmmmm. Ive had something similar where i found a loose jam nut. Maybe run though and check all the control arms atc.

[turbomart]

Should post this in GC section as Im sure another member had issues with double double carden shaft.It seems they are very particular about the angles.I reckon both double cardens need to be on same angle, ie need to rotate diff pinion down.

[vandan]

I just adjusted the long arm to it's limit to get as little pinion angle as possible (still not straight). This has made quite a big reduction in vibration however, the vibration now comes in about 10kph earlier (about 80kpm) and then gradually fades to only a little cyclic vibration by about 95-100kph.