Thread: Vibration on acceleration - Uni joints ahm no!

Howdy
Well the 1996 Defender 130 TDi 300 is still going strong and just had new tyres and rego all good!

nope a vibration on Monday under acceleration on way to work called for some investigation and found the rear Uni Joint on front prop shaft was cactus.

Does minimise if not accelerating or if you depress the clutch.
was making a scrape, scrape noise Tuesday when slowly reversing out the driveway / up hill.

Some new uni joints fitted last night and on way to work today the vibration seems worse?

So some questions.
I marked the orientation of one end and put it back together same as it came out. the other end I forgot so a 50% chance it went back together same as it came off and 50% it went 180 degrees out. would this cause vibration? I would not have thought so? The slide never came apart as it was in good condition.

It was late when it went back in but it is just 8 bolts so that too should not cause vibration or issues?

I should have checked the output flange on the Txfr case as I hear the bearing can fail there? If it had can it be done with Txfr case in the car?

any other ideas.

Thanks

james

Originally Posted by zwitter

...
The slide was well greased following recent rego but will give it a little more.

....

The only reason I asked about the grease situation on the sliding joint was that many decades ago, I had a similar issue on my RRC.
I was under the car giving it a bit of a service, greased the sliding joint(front shaft) and it started vibrating. Took me a while to track down where the vibration came from, not reaslising that after I greased the sliding joint it started to vibrate.
Anyhow, long story short, I eventually removed the front shaft and test drove it without the vibes .. so front prop it was. I changed the unis, refitted(marked to be sure I fitted it the original way) .. vibration remained.
Removed again, pulled apart, old grease completely cleaned out, joint seated, and there is was found to have half worn splines.
At that point, I didn't fit it again, took it to a balancing place got them to fix it up, and balance it .. I drove around for the few days or week in rear wheel drive mode .. and when the front prop was fixed I fitted it, vibes totally gone.

I remember the vibration would come and go, come at certain speeds, then go, and come back at other speeds again.
I changed many other parts before getting to the front prop shaft too tho.

So I only queried the greased sliding joint to see if something had changed in that area.

Did you mark the transfer case and diff flanges and prop flanges relative to each other too?
I was taught that when removing props you always fitted them back to their mount points in the driveline the same way as well as rebuilding the prop itself the same orientation that it came apart.
That is, make a mark on the TC flange and the propshaft flange whilst they're still connected, so that those two flanges are connected the same way .. and same for diff end too.

Did you check the T/C and diff flanges for wear, slack or play?