overdrive = bad vibration

Things seem to be going from bad to worse, for the last 2 days every time the tranny shifts into overdrive i seem to get a massive vibration through the truck until 55+mph

I'm going to change the fluid and filter (although fluid is clean), but does anyone know exactly what causes this to happen?

Thanks,

Craig

mine did the same and it was the u joints !!

Oh, sounds better than it being the tranny! Thanks man i'll check it out in the morning :)

I have heard this is due to a faulty torque convertor clutch solenoid. When your tranny shifts into overdrive the torque converter clutch is supposed to lock the torque converter up. If it is not working properly then the tranny will slip causing the vibration you described. I would keep the tranny in drive ("3" on the gear selector) until you can get it fixed to prevent any further damage due to the slippage. There are lots of posts on this problem search for "TCC solenoid" and you should be able to find more info.

I am tempted to change this TCC solenoid along with the tranny fluid, however I'm not having any of the other associated problems, such as it not locking up, or stalling when slowing down. The tranny does work perfectly and does everything when it should. (wish I had a temp guage on it, only option missing on my truck)

It is true however that if I keep it in 3rd that it does not vibrate, but I'd put this down to a different RPM speed.

Argh, I hate these situations! Looks like I may as well replace a whole load of things like a pre-emptive strike on my truck!

-Craig

That " vibration" could be a misfire generated only in lock up when the engine is loaded, then in 3rd the load is reduced and the miss disappears. Just something to consider, I don't think your description matches a u joint problem.