Gearbox/Drivetrain vibration

[kiwi surf]

Currently running 1990 2.4 TD 5spd Manual. Notice that when changing to 5th Gear around 80kph a bad vibration/resonance occurs. When I go above 80kph it disappears??. Any idea's??. I have read other notices and suspect that it could be propshaft problems, but why only 5th. Possibly Gearbox???

The truck spends alot of time on the beach but is regularly serviced.

[Robert Patterson]

If its a vibration like a buzzing, your probly right.... g/box bearing or d/shaft.
but if its a wobble... often caused by tyres....

If no matter how hard you try, you can't get it to do it in 4th, that would count out the flywheel/assy and drive shaft.

I think though, that in the mean time (befor total failure) you should just start checking though the T&E anyway for g/box... you could probly get one for $200.