name that clunk

[squeaky3]

ok so heres the deal

just built this axle 2k miles ago, 14 bolt sf 6lug brand new 4.56 gears and bearings, 156k miles on original trans and transfer case

u-joints seem ok, greased slip yoke with 5 pumps of grease

only makes bad clunk in reverse, only very slightly noticable when going into drive

heres some vids

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[badazzbulldog]

i'd say ujoints had one in our 99 silverado felt tight seemed good took shaft out it was frozen solid changed it sound went away

 

[Southern Pride]

Mine does the same thing...I get in it and put it in drive and it "clunks" into gear. I F'ing hate it. Every once in a while it doesn't do it and makes a smooth transition, but man I wish I could get it to go away...

Off topic:
Another thing I notice, is I have the hardest time finding the correct U-joints @ autozone. Every single time I put in my exact info into their database and they bring me out the wrong one. It is the same size on all of the ends, where as the one I need is 2 different ends...I know that's a terrible description but seeing if maybe just maybe anyone else has this problem?

 

[badazzbulldog]

have had same issue with autozone, had better luck with advance auto parts and c.a.p auto parts in my area for that same joint two of the caps are a hair bigger than the others

 

[Mean Green]

I also would say your problem is the U-Joints. In general that the telltale sign that the u joint is on it's way out. Does it also make the clunk sound at highway speeds when you let off the throttle then accelerate again?

 

[96k1500]

Mine does the same thing...I get in it and put it in drive and it "clunks" into gear. I F'ing hate it. Every once in a while it doesn't do it and makes a smooth transition, but man I wish I could get it to go away...

Off topic:
Another thing I notice, is I have the hardest time finding the correct U-joints @ autozone. Every single time I put in my exact info into their database and they bring me out the wrong one. It is the same size on all of the ends, where as the one I need is 2 different ends...I know that's a terrible description but seeing if maybe just maybe anyone else has this problem?

I always had the same problem but they always tried giving me the one you need when all 4 caps on mine are the same

 

[stroker52]

if it was me i would pull the rear end cover for the hell of it and check your back lash!!! sounds to me your gear is getting eat up... just putting 2 an 2 together...

gear change + 2000 mile!!!

 

[DRAGGIN95]

I was going to ask did this clunk start when you rebuilt the rearend?

 

[stroker52]

ive built well over 50 rear ends and most of them he put though hell an back lol.. 75mph around as dirt track lap after lap.... all with stock axles and a 7.5 rear end.. we break more carriers then you can shake a stick at lmao...

to me it sound like he didnt get the pinion depth set right and now its knife edge the gears... most of the time you can take the stock shim from the pinion gear and put it on the new gear with the new bearing and the pinion depth will be right on the money...

 

[Toms94z71]

yeah they list about 10 different Ujoints on the catalog at work for my truck, but I've learned that 354s are usually the front on the rear drive shaft and 355's are the rear usually on a extended cab short bed, but there are different ones for rcsb, rclb, exlb, crewcab, and then for the different axles, and transmissions, not to mention the head ache you get when some one is trying to piece together parts from trucks that were made in different decades and even different makes.