My vote is also for the slip yoke in the transfercase. I have seen it many times. pull the driveshaft out and clean the splines on theinside of the yoke and coat it with some grease before you reinstall it...Let us know if it helps.

 

thanks, I gotta try this one and soon somehow. This is too easy if it cures the clunk.

 

Thanks guys, I think the clunk is cured. I got a chance to get under my truck with the bum foot in tow. Removed the driveshaft and brushed and greased the slip yoke. There was not any major slop at either end of the driveline. Took it around the block, giving the driveline some major jerking of hard stops and starts. No clunk... nothing, just solid stops and starts. I will test again tomorrow. Thanks again, now for a zerk fitting on my ankle.

 

Hmmm, I'll have to try this one too. I just swapped rear ends and the problem hasn't changed for me.

 

well i thought i might also have to change the rear end. I have the same Clunk and was wondering doesnt anyone ever post after they fix the problem. what the problem really was.

 

The 8.8 rear in my '88 5.0L 5 spd Mustang, which is the same rear used in my '95 F150, had a real bad clunk inside the differential which I was sure was excessive back lash between the ring and pinion or bad bearing etc. And it was a loud noise I am talking about here. So I took off the rear cover and ring pinion back lash were in specs and all bearings were tight. What caused the clunking was excessive wear on the traction lock clutches which caused excessive slack in the spider gears and they were what was clunking (or knocking if you will). When the tracton lock clutches wear down the spider gears are pressed outward causing excessive slack in the spider gears. So I replaced the clutches and did the extra clutch mod and shimmed them so tight that the cross shaft just barely fit in and that rear has never felt so solid since I have own the car (I bought it new in '87). One trick I did learn is you can put a dial guage on your axle and move it in and out and that is how much slack you have between your axle shaft and differential cross shaft. When traction lock clutches wear the spider gears move outward and excessive in/out axle shaft movement will be present along with clunking spider gears. For you traction lock diff owners Ford sells a kit with shims and new clutches along with instructions. And the diff does not have to be removed from the housing to replace the clutches.

 

Is this a DIY project? What's the cost? I may have this issue with my 8.8 LS.

 

Thanks 95F150SuperCab,

Not many people are talking about what they did that eventually fixed this problem