vibrating overdrive

[longboarder]

Engine and box running great, but when I snick it into overdrive it sets up a vibration, almost like the prop is out of balance, its not severe but it is there, its not in any of the gears only when I flick the switch, any ideas? remember the car never turned a wheel for 14 years, but was well maintained until then.

[slant4]

you could have some issues with corrosion on the rear bearing of the overdrive, or is the mounting gone to putty?

[longboarder]

Good spot, the mounting is a bit cracked,dry, split, gooey,(is that a word?) Tried it again yesterday and it was a little better, I think, . Does gear oil go off, I mean absorb moisture or break down, it appears to have the right amount in there.

[Stagger]

Is it a vibration or a noise? Are you sure its not the gear knob switch vibrating due to resonance with the extra OD gears running ? Does it stop if you put your thumb on the switch?

[longboarder]

Yep, definately a vibration, almost like the uj in the prop is shot, but it ain't. Gave it a long blow out and kept it in overdrive for a while and it does seem to be going away, slightly. Maybe just 14 years of not turning, hopefully. Will give it a couple of tries before I get worried to much, it appears fine in 3rd. and 4th. Maybe I should leave well alone.
Thanks for your input, input.......gearboxes, get it?

[longboarder]

Changed the oil in the box and the oil in back axle, plus greased the u/j's in prop, there are 2, then took it for a good talking to and problem cured. RESULT !! Clicking in and out like it should and no more vibrations, Taking to Lands End tomorrow, that should give it a test.