Outer Limits 4x4 Board

I have some issues with a vibration somewhere in the driveline whilst under load, i need to replace the driver side engine mount, but am concerned that this is not the problem, because there is a clunk coming from down there upon take-off as well. Has anyone had similar issues?

sounds like a uni to me
replace universal joints per pair per driveshaft

Could be worth trying to grease them if they haven't been done for a while.

Have you done any modifications to the suspension in the last few months, been wheeling hard or dissasembled anything related to the driveline recently?

The Uni's in the rear are 20 months old, every 6 months they get grease, but i'll try more. I put another transfer and new clutch in 9 months ago but don't think that has any problems. I had some issue's with the tailshaft bolts getting loose, but fixed it, maybe that put stress on the uni's? The front drive shaft is pretty worn, but i don't think that the vibration comes from the front.

More grease will just fling out at rotational speeds - at top speed it will be rotating at faster than engine revs - and the uni bearings don't rotate much if you haven't lifted the car much to create excessive unit angles. Perhaps the slip join is getting a bit loose/worn. Have the two halves of the driveshaft been separated, and perhaps not re-aligned correctly?

Did a shop replace the unis?

The shaft should have the unis in phase at each end - rough diagram:

Thanks Area54,
I think you hit the problem one the head, i checked the driveshaft, and it was alligned incorrectly. I've re-alligned it and the situation seems to have improved. I'll see how it goes over the next week. A shop did the uni's but i did the tranfers case and and was the last to have the driveshaft off. There's a bit of movement in one of the uni's which has probably resulted from the misallignment for a trip to Adelaide and back (coast road with camper). All seems go though! Thanks heaps

IIRC the Feroza manual says there are paint marks from the factory to show where they should all align- maybe the Rocky is similar and if you clean all the flanges up you might find something??

Wouldn't hurt to make sure you have plenty of lok-tite on the bolts too. They come undone very easliy after ther have been undone once.

Which isnt fun to have happen at speed, about 110km. The whole car shakes like shit.