vibration

[shad]

iei have a 95 defender 110 with a vibration that seems to come into it at between 80-100 ks have recently had gearbox redone.when i press clutch in it goes away any ideas appreciated.ie sitting on 85 with vibration happening then putting foot on clutch it cruise beautyifully with no noise whatsoever

[spudboy]

Ooooh - there's a quite a few things to look at.

Start with the obvious ones, like wheel balance, etc, but I am going to say check your Universal Joints. Any movement, even a teensy bit: replace them. Try greasing them up (nipples on each UJ + sliding joint) and taking it for a run. The new grease will fill the gaps in the UJs for a short while. If the vibration goes, that's probably your issue.

[shad]

after having the gearbox done just talked to mechanic,the front drive shaft was just bolted straight back on can this have been put on up side down?it wasnt removed from front diff just unbolted from gearbox apparently they have to have some offsett due to angles of motor etc.does this fix the offset problem or am ijust wasting my time if it was up to the mechenic he tryed telling me they just go in line:mad:;)

[spudboy]

The front prop shaft is "phased" - i'e' the UJs to not line up.

I think it is a 30 degree offset, but not sure. You'll need to do a bit of searching.

However, if your mechanic didn't pull the prop shaft apart, then is should be in the same state that it was before any work was done.

[Jojo]

My bet is on the UJs as well. The fact that the vibration disappears when you declutch almost excludes wheel imbalance as the wheels wouldn't be affected by pressing the clutch pedal. You must check all UJs, not only the front ones.
Having said all that, I had similar problems a while ago, and they persisted, despite re-balancing the wheels and changing the UJs. It all but disappeared when I fitted a new set of tyres. So probably one of the tyres had developed an internal fracture or similar which was causing the problem. If you have a second set of tyres available (or can borrow one from a mate), try fitting these and check if the symptoms persist.

[d2dave]

The only accurate way to check uni's is to remove tailshaft from vehicle. A uni with play can be checked in car but if it is seized or seizing you will only pick it up with shaft removed.

Dave.

[LRCounty]

The only accurate way to check uni's is to remove tailshaft from vehicle. A uni with play can be checked in car but if it is seized or seizing you will only pick it up with shaft removed.

Dave.

Yep..had this recently. I pulled the prop shaft to replace the uni joint with play, then had to go and get another Uni-joint for the other end that had no play, but was seized.

Then a week later after an off-road trip, a vibration started again.....that time, it was flogged out front radius arm to axle bushes, allowing the back of the diff to drop and increase the angle on the uni joint.

Cheers
Andre