My 93 F-250 w/ 7.3L N/A E4OD last night started to vibrate while slowing down. But there is no vibration when I give it a little bit of gas or foot to the floor but as soon as I let off the pedal the truck starts vibrating only when moving at any speed. No vibration when standing still idling, or reving when not moving. I want to think it could be the rear end. Any ideas before I tear the whole thing apart?

 

It could be torque converter shudder. When was the last fluid change?

 

The Fluid is probably in the 60,000 mile range. but i went ahead and put the truck on the lift and one of my U-Joints was very loose. Just picked another one up and Im gonna install it and hope thats the problem

 

them 36" super swampers kinda would have a tendency to do that to U-joints.
keep us posted.

my thoughts jumped right to andym's reading your post too.
fyi,depending on trans temps,your about twice overdue for a trans fluid change (if using dino juice still.)

 

the u joint was probably the issue. my truck did the exact same thing, and i realized that my driveshaft had loosened from the pumpkin

 

Yes, change your tranny fluid ASAP. You are way overdue.

 

Well I've never had this problem before. I cannot get the U-joint off. I took the four bolts off the pumpkin side and took the shaft out of the transmission and I put the drive shaft into the vice and I cant get it to budge no matter how hard I hit it. Gonna break out the torch tomorrow to heat it up and try again.

Transmission.... trying to fill up 17 quarts gets a little expensive sometimes. (Just dropping the pan, ATS Deep Pan) I was told to change the transmission fluid every 80K miles. How often am I supposed to change it?

And im not running the swampers anymore, got just a little too expensive and im running on a set or tractor trailer tires.

 

as general rule; 15k-20k miles towing/off road/working her good,30k miles normal driving.
true,it's not cheap to flush a trans every 30k miles max,but sure is cheaper than replacing it.

Mercon or Mercon 5 only.

 

Well thats good to know, never listening to my dad again on when to change transmission fluid.

 

Try pressing it out with your vice. Put a socket that's barely smaller than the yoke ID on the u-joint cap on one side with a socket thats larger than the yoke ID aginst the outside of the opposite side.

 

You can also rent a ball joint press from Autozone. The tool doubles as a u-joint press. If you can't get it out with that, then someone tacked it in place.

 

I got it out and replaced. I used the socket idea plus thje heat from the torch and it popped right out. New U-joint is in and the vibration is gone. Transmission fluid was changed as well.

 

Thank you everyone for your help

 

My Dad used to change the tranny fluid on his 83 AOD after hauling his trailer to Fla from Maine every Oct. Truck and tranny lasted 218k miles.
regards
rikard

 

305K miles and still running strong. Transmissions is around 150K by now I think