bad vibrations

[bad_religion_au]

you may or may not remember i had a few bad vibrations. well i fixed them, by replacing gearbox and transfer case, driveshaft was ballanced and new uni's installed, and a new 3rd member... 10 000 k's later, vibrations are rearing their ugly head again. accelerating above 30 km's an hour, the vibration is there, maintain speed, back off, or go under this speed, smooth as silk

but, corner above 30km/H accelerating, and it's smooth

 

[66fj40x2]

Could this post from another thread have anything to with it?

good god, i don't ever want kids, my brother just turned 18 (legal driving age in australia)... the first day he went out on his own, i was worse than mum and dad... they played on that too, he was 2 minutes late home from work, mum came in with "jeez you'd think he'd be home by now" and laughed her ass off as i grabbed my keys and wallet, busted a perfect 180 on the lawn in the 40, and chirped them in second as i raced out to make sure he wasn't in a smash... after all, i taught him almost everything he knows... and i know what he's like, same as i was... who really knows why 18 year olds think it's a good idea to do donuts in diesel 45 series cruisers?

Sounds more like the driveline being out of alignment but I'm no expert. If the your fixes worked the first time start there, but do them one at a time til get it corrected. That would at least tell you exactly what the issue is and maybe how to fix it. Just my 2 cents.

 

[bad_religion_au]

last time i did do them one at a time. the driveshaft did nothing (but was cheapest place to start) the diff fixed the vibe, then the gearbox blew itself to pieces.

the vibe started well after the fast takeoff.

 

[Pin_Head]

Vibration that changes with acceleration / deceleration may e due to wear and slop in the slip yoke splines of the driveshaft.

The other suspects are:
Angle mismatch at the U joints.
DS ends out of phase.
U joint angle out of range limit.
U joint wear/improper installation.
Los of preload / slop in TC output / diff pinion.
Bent, dinged out of balance drive shaft.

 

[bad_religion_au]

or loose driveshaft bolts DOH

 

[IDave]

Are that what U found?

 

[Pin_Head]

or loose driveshaft bolts DOH

I think that would qualify as improper installation.

 

[trainrech]

What kind of shape are the pinion bearings in?

 

[bad_religion_au]

yeah that's what i found.

it's driven 10 000 k's since it was last removed... i used locktite and everything, and checked it every day for the first 1 000k's... then every week since then, they were tight a week before the vibration started... doh