Lwb eating uni's

[mrRocky]

Hi all, replaced my uni's and a new jackshaft to boot about 6-8000k's ago
and again my jackshaft uni and rear t-shaft uni are buggered, I have since replaced the t-case mounts with h/duty ones which have limited vibrations a bit, but i still get a horrible vibration through the driveline at 70kmhr because of the uni's which are of to be replaced again tomoro.
I have only been through water once since having them replaced.
The only other contributing factors i can think of are
*maybe the 3/4 elliptical
*Exess backlash in t-case to j-shaft flange (no bearing movement)
*Welded rear putting too much strain on uni

Got me stumped ???

[nicbeer]

what lift is in it?

yes welded rear does put more stress on it.

i have same issue in mine but also spring wrap in mine was hurting it also

[alien]

i'd say its excessive rear flex causing it... you're flexing it under power and chewing them out. I've feared this with my front shaft but all is ok so far - however i do feel it binding when im fully flexed now and then.

weird that it occurs at 70km/hr though... could just be a frequency thing causing the already worn joint to vibrate?

Are the shafts balanced and pinion angle correct?

[mrRocky]

ok apparently the shaft was rooted and the pinion angle was way off
I only have 3" of suspension lift so it all seems a bit odd to me as ive had swb's with more lift and less probs.
Had some shims put in the rear to correct pinion angle slightly, i can still detect a slight vibration so i reckon that fixing all these things have just masked the underlying issue or maybe im just too fussy ???
Time will tell i guess

[bazooked]

go to verriers, he can check all ur driveline angles and while ur at it get ur shafts balanced properly, also get rid of the stiff mounts and replace them with normal suzuki ones, but drill them right out and put a bolt thru them, ur hd ones will cause vibes aswell.