I have a '95 4x4 f150, 302, automatic (not sure which tranny, but I know it isn't an E40D). The truck is lifted a couple of inches, has manual locking hubs. Whenever I take off from a complete stop, I can feel and hear a thump that seems to be coming from the rear of the truck. There is also a bit of a lurch associated with the noise as the truck takes off.

I haven't noticed any additional problems once the truck is moving. It seems to have gotten worse. I recently had all the bearings and one axle shaft in the rear end replaced after a leak developed. I was told the other axle shaft had been replaced before.

The problem existed before the repairs, but not frequently enough that I felt compelled to look into it. Any ideas what the problem might be?

 

Try dropping the drive shaft, and smearing a good load of grease on the splines of the slip joint. Reassemble and test drive. If the cluck is gone, a worn slip joint is the problem. The grease doesn't fix the problem, but it lets the joint work without getting stuck and causing the lurch/ clunk on take off. The grease will not last a long time, but might buy you some time to figure out what to do next. I drilled and tapped for a grease zert and shoot the joint when it starts clunking. I don't drive my truck a lot.
Good Luck Frank

 

I have the same issue, and i've been told the same thing about the slip yoke. I am going to try that soon.

Also want to add that I had a truck before and had something that seemed a lot like this and when i told it to a shop after not being able to track down the issue myself the guy found that my torque converter came loose and the 6 or so bolts had ovaled the holes like 3/4 an inch. Ive heard this is pretty rare but if you run out of possibilities you may want to look into that.

Good luck
-Jesse

 

Is the slip yoke the one that goes into the trans or the one into the rear? I have the identical truck setup but in a 1996 longbed with one piece driveshaft. Thanks.

 

Well, there could be 2 slip yokes,if you have a 2 piece drive shaft. One that goes in the trans,and the other by the carrier bearing,which you should also check.

 

Its a one piece driveshaft. which end would the slip yoke be on. Service manual does not say.

 

Slip joint is on the trans side. Id also check on the U bolts. Look for fresh rust, shiny spots, or loose nuts. If they have lossened, could be allowing the rear end to roll forward when you accelerate.