Drive line CLUNK and FIX!!!

[19992dr4x4]

Ok, so I have posted on here that I was having this clunk when I would get to the gas after a stop. Let me start buy saying saying I have wasted TONS of money and countless opinions and finally I have solved the problem.

My chain of events...
Trans goes out and replaced with a GM trans. After that I had this clunk sound from the rear end and I swore it was my rear diff. The chase began, rear end serviced and carrier bearings replaced...no fix. One tech thought to be leaf spring bushings (the where basicly gone)...no fix. New slip yoke and u-joints...no fix. I had another tech swear it was the rear diff, I just couldn't throw $500 towards something I really felt was not the problem...didn't do it.

The FIX...trust me!!!
I have a friend that's a parts manager for a local GM dealer and he pulled a GM bulletin from several years ago on this issue. The bulletin states to replace the slip yoke with a nickel plated one...had mine replace but not the nickel plated one. And also put GM Auto Trac II (blue) in the transfer case with this special GM grease on the slip yoke.

So I check the fluid in the T-case and low and be hold the tech who installed my new trans must have put regular trans fluid (red) in the T-case...BIG NO NO! I flushed the trans fluid out and added the GM Auto Trac II fluid and loaded my slip yoke with the GM grease and now my truck runs AWESOME no clunk at all!! So before you go and have different opinions just check your t-case fluid and make sure you put the GM auto trac II fluid if you see the red. My truck has 195,500 miles on it and I believe now it will go for a bit longer! There must be something with the blue fluid that really lubricates the gears in the t-case and the GM grease really keeps it soft on the yoke splines.

Just had to let all know.

 

[SunlitComet]

W have already know this. I would have told you this as soon as I read the chain of events. if is is clunked from stop.... Grease the yoke.


However not all people here should use the Autotrac II lube. Only those with a NP8/nv24 Auto 4wd system transfer case only. They were an option starting in '98.
red dexron tranny fluid is used in others.

 

[Donnie Yukonie]

If it helps I didn't know lol


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[SunlitComet]

DAM YOU!

 

[yukonnw]

Drive line clunk

What kind of grease did you use on the slip yoke? I see you talked about the "blue" fluid, but what type of grease on the slip yoke? Some are saying a marine grease that is thick and waterproof...? I want to do what you did, please let me know what kind of grease you used. Thanks!

 

[96redsport]

I have the same issue going on that started immediately after replacing the rear Ujoint. Just haven't got around to grease the yoke yet to see if this cures it which it probably will.

 

[cdaulton]

sub'd for future use, my wife's 99 Yukon is doing this and my thought was a loose chain in the transfer case because there is play in the drive shaft and I could hear noise in the transfer case.

 

[RedCrush]

true dat, not all use the blue oil... mine uses red dexron and its a 1997.

 

[OkcLarryD]

Mine's a 2WD so I really don't give a flip.

Some nasty remarks on here, I'm merely sarcastic.

 

[GA_Boy]

Ok so if I am reading this correctly you are saying that when ever you are stopped some place and then you start to move forward you sometimes get a clunking sound? I get this myself sometimes and have been trying to figure out what it is or what could be causing it as it does bother me sometimes.

I just transfered down here to FT. Polk, Louisiana from FT. Knox, KY and noticed my Tahoe doing this. For all i know it might have been doing it while I was in KY and I just never eally paid attintion to it.