I have a 1995 Ford F150 already replaced the front ujoints and bearing thinking that would fix the problem with no luck. Itsiunds like metal clanking around whenever i release the gas pedal aroun 20-25 mph is when it is really noticable and does it in both 4 wheel drive and 2 wheel drive. Mosy of the time it is worse in 4 wheel drive and the wheels will lock up if i turn hard left in 4 wheel drive. Appriciate anyones help.

 

Check the pinion bearing on the rear axle. Put trans in neutral, then grab the pinion flange and see if there is any play.

It is normal for the driveline to bind when turning sharp in 4x4; just allow the steering wheel to turn back a little as you make a corner.

 

I am having a similar problem I changed my 351 Windsor and transmission and transfercase replaced it with a big block 460 and new trans and transfer case it made the noise before and after the engine swap so I know it was not the drivetrain so if anyone has an idea it would be appreciated

 

I've had that problem in the past too. Mine was a U-joint in the rear drive system. If yours is happening in 2 or 4 wheel drive it may be one of the rear U-joints. Sometimes I couldn't tell if they were toast until I jacked the truck up and was able to turn the driveshaft easily by hand. Mine didn't always shake or show any slack/play with the truck on the ground. I don't know why but that's just my experience.
Don't worry about the truck locking up when turning while it's in 4x4 mode. That will happen if you are on solid ground. Try to avoid tight turns while in 4x4 mode unless you are on a slippery surface.

 

Thanks that was it. I tried moving the driveshaft originally in drive and didn't see any thing wrong but this time when I put it in neutral and moved the drive shaft it was very noticeable. There was nothing left to the rear u joint so I replaced both of them. Appreciate all the help saved a lot on the guessing game. Thanks again hope I can return the favor in the future.