I just put all new brakes on the truck, along with a new rear end last week. I drove 2000 miles out to colorado and back, everything was fine. now this week i get a clunk when i first step on the gas, and when i first hit the brakes. it doesnt clunk over bumps or anything else. if i stay on the brakes it doesnt clunk, if i stay on the gas it doesnt clunk. its only the initial...i checked all of the caliper bolts, the link bolts in the rear, crossmembers etc..cant find anything..any ideas?

 

Could be the slip yoke on driveshaft where it enters the trans.

 

Yep... look at the driveshaft/u-joints.

 

Have yet to see a truck that does not do it at one point or another... Some clunk so bad you look in the mirror to see if you been rear-ended by someone lol. Take the shaft out, fill it about half full with a PTFE grease, slide it back in and it will stop for a good while then repeat...

 

so even when i hit the brakes it could make that happen?

the rear ujoint was replaced a few months ago when i did the trans..but ya i will try that with the slip yoke..i can feel it under my feet when it happens..just kinda freaked me out

 

I hate this my truck does the same thing I already greased up the slip yoke and it really helped but I still hear the stupid clunk makes me wanna burn the damm truck. Ive also heard that if you get a bouncy ball and cut it in half then slide it into the slip yoke that it will help has anyone tried that?

 

I've heard of that but haven't tried it...I replaced my slip yoke with the "updated" nickel-plated one when I swapped my trans back in May/June, so far so good...

 

I do wonder what causes the clunk is it the slip yoke sliding back and forth hitting the output shaft on the tranny? or Is it that is has play in the splines of the yoke and output shaft? Im guessing its sliding im gonna go by a bouncy ball this weekend and see if it works this is driving me nutz I dont even like to drive the truck because of this

 

does it feel like its under your feet when it happens?

 

Good question...I thought it was the splines, which would explain why grease helps, but that doesn't explain the rubber ball method. I can't see the yoke bottoming out on the output shaft and not creating other problems though