# clunk shifting from reverse to drive and back



## bison1973

'99 chevy 2500 116,000 mi- has a lound clunk when shifting from reverse to drive and drive to reverse. It is annoying. U joints look fine. What's the problem with it?

tim


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## jcesar

Did you Check to see if there is any play in the ujoints? I have had them be almost new, but still have play.


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## bison1973

well, just by getting under the truck and using my hands to see if there is play I don't find any.

tim


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## jcesar

Not to sound redundant, but maybe there is play in the rear yolk?


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## bison1973

I'm getting it checked by a mechanic later this week. Any info from anyone I can get before then will be helpful.

tim


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## dlcs

My '99 Chevy Silverado 2500 has made that noise for at least 2 years. I have had a Chevy mechanic and independant mechanics tell me that its not uncommon. They said its most likely back lash in the rear end. Mine only does it going from drive to reverse or reverse to drive. i can lessen the clunking noise by putting the truck into neatral for a couple of seconds, before changing to reverse or drive. The Chevy mechanic said that it always sounds worse on a extended long bed truck cause of the length of drive shaft. Basically the longer the driveshaft the louder it sounds, kinda of like a big tuning fork. I thouhgt thatmaybe the idle was too high and that it was slamming in gear but I was told that isn't causing it. Since mine started making this noise, I hear about this problem alot with the Silverados. Do a search and see the thread I started on it.


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## DBL

our 91 dodge does the same thing i hope this isnt serious


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## jcesar

Bison, 
If you figure out what it is, please let us know.
Hope it isnt serious. Good Luck


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## lawnmedic

If your truck has a carrier bearing make sure it is getting lubed. Had same problem cured by greasing carrier bearing assembly.


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## scaper27

It is the rear housing. It is expanded and there is play in the housing. It will do it for years and thousands of miles. Don't worry about it. I have it in both 99's and I know have 86,000 on one and 100,000 on the other, No problems. You have to replace the whole rear housing to get rid of it. Good luck. I deal with mine


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## imdawrlus

try greasing the slip yoke where the driveshaft connects to the tranny.

sometimes they stick and clunk when they free themselves.


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## Mark13

my 98 k1500 does it to, so its a fairly common problem i guess but it doesnt seem like its worth worrying to much about


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## Proscapez LLC

I just took mine in about that same problem on my 04. He told me the rear Yokes are the problem and there is a TSB on it they fixed it in a few hours and even replace my rear end fluid.

It sounds like a brand new truck again now......


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## rcpd34

I had a similar clunk and even though the U joints looked fine, I replaced them all at the same time and it went away. It will eventually fail if you let it go long enough. Probably at the worst time.


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## JeffNY

My '94 1/2 ton was doing this for about 4 months....U-joints were new. After the 4mo, the tranny self distructed. Now its a lawn ornimate for a while.


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## Brian Young

You have to take pressure off of the drive line in order to check play in u-joints. Jack it up then see if there is any play.


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## Rcgm

I had same problem it was a lound clunk in my 04 silverado I replaced u joints it was fine after that.I didn't thin u joints were bad but dealer said they were.


RCGM
Brad


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## RYDER

It is most likely the U-Joints. If you jack up the rear-end than get under the truck and rotate the drive shaft back and forth you should be able to tell witch one it is, But the truck wheels need to be off the ground!!!!!!!!wesport


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## bison1973

*'99 Chevy shift clunck*

I'm the one who originally started this disscusion. I had the truck looked at and the mechanic said the u joints are fine. Sure dosen't sound fine though. He said this is something that happens on GM trucks and there's not much one can do about it. I mean it's a MAJOR clunk on my truck. Although it dosen't do it nearly as badly in 4WD. Anyone out there have this problem and have it fixed? What was done and what did it cost?


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## rcpd34

bison1973;336937 said:


> I'm the one who originally started this disscusion. I had the truck looked at and the mechanic said the u joints are fine. Sure dosen't sound fine though. He said this is something that happens on GM trucks and there's not much one can do about it. I mean it's a MAJOR clunk on my truck. Although it dosen't do it nearly as badly in 4WD. Anyone out there have this problem and have it fixed? What was done and what did it cost?


Find another mechanic. That's the wrong answer. U joints fixed mine.


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## scaper27

bison1973;336937 said:


> I'm the one who originally started this disscusion. I had the truck looked at and the mechanic said the u joints are fine. Sure dosen't sound fine though. He said this is something that happens on GM trucks and there's not much one can do about it. I mean it's a MAJOR clunk on my truck. Although it dosen't do it nearly as badly in 4WD. Anyone out there have this problem and have it fixed? What was done and what did it cost?


It is an expansion of the rear housing. You have to buy a new housing for the rear. Ultimately a new rear. Trust me. It is not the U-joints. Also you should be able to hear that noise for anther 50K


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## Proscapez LLC

bison1973;336937 said:


> I'm the one who originally started this disscusion. I had the truck looked at and the mechanic said the u joints are fine. Sure dosen't sound fine though. He said this is something that happens on GM trucks and there's not much one can do about it. I mean it's a MAJOR clunk on my truck. Although it dosen't do it nearly as badly in 4WD. Anyone out there have this problem and have it fixed? What was done and what did it cost?


Back lash does not bang or clunk if you listen closely you can here the back lash.
I think you have the same issue I did, with it being the rear yoke and there is a TSB on it.
it was all no charge I think the part # is 12477702
What ever you do don't let them leave it as back lash, I had to get them to bring out a second mechanic to listen to it.
The first one said it was back lash, and I called him out on it and acused him of being deaf. the second mechanic agreed with me within 20 seconds and said thats the rear yoke. Now it sounds awesome and the back lash is so faint you can't even tell it's there unless you really try hard to notice it.

That part number is correct www.gmpartsdirect.com says the yoke list for $227.15 there price is $134.66


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## Rcgm

Ok I keep hearing about greasing the yoke.Where is the yoke and what do you grease it with?Tell me how to find it.Do I have to take anything apart on my truck?Someone PM me with directions I am lost with this one.


Thanks
RCGM
Brad


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## bigfoot1

I have a98 3/4 ton Chevy that had the exact same problem and a mechanic told me the same thing. So I took off the drive shaft took it to a shop had the shaft re balanced new U joints put in and the yokes straightened cost me $125. and have had no problems since. You cant tel if U joints are necessarily bad by wiggling them


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## Proscapez LLC

I have always used a bar to check u-joints, sometimes they are hard to see by turn with your hand.
but the bar always shows you the problem, it just takes a little muscle.


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## bigfoot1

A monkey bar yes wiggeling them no Some peopel go under ther and shake it with there hand and expect to hear some thing not gonna happen


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## WildRidge

I had the same problem, even would clunk after I would take off from a stop light that was downhill. I fabricated a little spring to stick in the end towards the transfercase, greased it all up, and haven't had a problem since.


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## bison1973

*What do you mean by "little spring"?*

WildRidge, tell me more about this solution you've come up with.


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## east end turf

94 chevy 1/2 ton 8' weastern enow ex 1870 sander . and i carried 3/4 of a pallett of salt in back for weight . i just changed spider gears pin axel bearings and seals in rear . truck would roll foward 10' when put in park!! i abuse the **** out of this rear truck has 140,000 at 120,000 the tranny blew up after a 24"storm and 36 hours straight so i dont have a problrm with it letting go !! jack one wheel off ground and see how far you can move tire i would like to know what you find!


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## Rcgm

WildRidge;341218 said:


> I had the same problem, even would clunk after I would take off from a stop light that was downhill. I fabricated a little spring to stick in the end towards the transfercase, greased it all up, and haven't had a problem since.


Wll Wildridge I am from Indianapolis to wanna make me a little spring to and put it on my truck ? 
I will trade you for some bags of salt not like we are ever going to use them here.

RCGM
Brad


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## WildRidge

Rcgm;343093 said:


> Wll Wildridge I am from Indianapolis to wanna make me a little spring to and put it on my truck ?
> I will trade you for some bags of salt not like we are ever going to use them here.
> 
> RCGM
> Brad


LoL....no joke.

I could fab. a couple of these up and ship them out to who ever would be interested as long as those that are interested are willing to cover materials and shipping. If you would like I could include detailed instructions on how to install the part too.

Or if you are mechincally inclinded and just want the detials I guess I could be a nice guy and share those with you. 

Just drop me a pm.

- Joe


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## east end turf

bison what did you find if chevy needed a little spring in the driveshaft they would make one! second pull the rear cover and take a look you have to to change fluid! very interested to see what you see my e mail is [email protected]


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