alright, i've got to get to the bottom of this. every damn ford truck i have ever owned has done this and i don't want to put up w/ it any more. when i hit about 38k miles on my truck, i started to get a clunking noise from the rear diff whenever i would go from D to R or let off on the gas and accel again. i pulled the driveshaft and lubed the yoke. there was absolutely no slop in the u-joints. when i put it back together it was just as bad and the sound was defenitely coming from the diff. both of my rangers did this and so have my 96-98 f-series. what gives?! can't dana or whoever makes these things get it right? what can i do to get rid of the noise??????????????? if whoever reads this doesn't know, could you tell other gurues about the problem so that my frustration can be ended.

 

My "clunk" had something to do with the rear leaf springs. I don't recall it happening going from D to R, but would do it after coming to a stop and then going again. When the truck was in park, on level ground, and the parking brake on, I could not twist the drive shaft at all, so I knew that was not the problem. If it was, there would have been play in the shaft and it would have twisted some.

I noticed it would not do it when I had a load in the back. Saw some other posts talking about the leaf springs. If you search under Suspension and use the keywork "clunk", you'll get some more info.

Some have solved the problem with new leafs, but I added some "helper" springs to give me more support in the rear when loaded, so this puts tension on the leafs all the time and keeps them from moving or whatever they did to cause the clunk. Worked in my case.

 

Mitch, your response is the most logical. My '98 did the same under the same conditions you mention. Although, my '01 SC was in the shop recently for a buzzing vibration and the dealer said they found a bad contact pattern between the ring and pinion. This wouldn't cause a clunk, but I also have to wonder about Dana's QC.

 

My HD 2000 did it all the time, and still does on occasion, but the superchip changed something for the better in the trans. prog. engagment cycle on part throttle and P to D engagment. Still, there is a problem, but I believe it to be inherent in the trans. not the rearend or driveline. I wish I had the R100 instead of this one. Good luck on getting the problem solved!

Later,
J&JHalo

 

Ive owned a 94 full size bronco, 97 expedition, 86 mustang, 93 mustang, and my 2k f-150 and they've all had slack in the drive train. My f-150 isn't that bad though, I think it's typical Ford