Transmision Vibrations!

[jmstelzer]

Hello I just purchased a 96 superduty powerstroke. Love the engine but am having lots of vibrations from the transmission. It seems to increase with speed. It is most noticable when you are not accelerating or slowing down. There also seems to be a short grinding noise right after you let off the accelerator pedal. There used to be a PTO hydralic pump on this transmission and the cover for the PTO gears seems to be leaking a bit. I know for a fact the clutch has virtually no miles since changed and the transmission only has 60,000 or so total. Any help is much appreciated. The transmission is a 5 speed ZF heavy duty.

[shahin214@hotmail.com]

I just purchased this well maintained truck, 4 speed with overdrive. when I go through the first 3 gears fine but when it shifts into od. it shakes if I;m below 60mph, anything over that I'm fine. So I leave in od off position until I hit 60mph. Is that normal for that tranny,will it harm it.

[CHenry]

Originally Posted by shahin214@hotmail.com

I just purchased this well maintained truck, 4 speed with overdrive. when I go through the first 3 gears fine but when it shifts into od. it shakes if I;m below 60mph, anything over that I'm fine. So I leave in od off position until I hit 60mph. Is that normal for that tranny,will it harm it.

Sounds like U joints maybe....check them for play.

[Eric B]

shahin214.
Try changing the fluid and filter and refill with dextron, mercon fluid. If that don't fix it get ready too install a new converter.
jmstelzer,
Sounds too me like a bad u-joint or a carrier bearing (mid shift bearing) going bad, Does the truck idle rough? or does it sound like a coffee can full of bolts at idle? If it does IT maybe time for a dual mass flywheel.
A dual mass flywheel will cause a shake at highway speeds with little or no load on the truck(cruising speed flat road).

[SuicideAxles]

If it isn't U-joints causing the vibration (check by seeing if the vibration exists by increasing RPMs while transmission is in Neutral), then I'd say it's the flywheel. I had similar vibration issues on my '96. Vibration at 1,600-1,700rpm, then it would settle out, then come back around 3,000rpm til redline. I replaced my clutch with a LuK RepSet, and swapped the stock dual mass flywheel with a LuK Solid Flywheel. Paid just under $600 for both with taxes and delivery. Now the truck is smooth shifting, took alot of the harsh clutch pedal out, and no vibration.

[shahin214@hotmail.com]

it's only a small vibration in o/d from 50-60 after 60 its gone.any other gear at the same rpm or speed is fine just o/d. it just feels like it's shifting to early.
o/d around 50 instead of 60mph

[straycat]

Originally Posted by shahin214@hotmail.com

it's only a small vibration in o/d from 50-60 after 60 its gone.any other gear at the same rpm or speed is fine just o/d. it just feels like it's shifting to early.
o/d around 50 instead of 60mph

Had exactly the same problem in my 99, checked everything and it was all good. turned out to be a bad fuel injector of all things, when it went into od at about 50 or so it would start vibrating till about 60 give or take, changed the injector and it was all good.

[03liftedcrew]

Ive got a 03 7.3 auto 4x4 that has a slight vibration through the first two gears and then is perfect going down the highway. It only has 35000 miles on it and the only thing ive ever hauled is a small car trailer, what could it be?