Rearend clunk,, this can't be good

[inkadink]

This just started yesterday. I apply the brake and put my 97' Hoe in drive and I hear a clunk then shift into reverse and hear another very audible clunk.

I do not believe it to be the u-joints because I can crawl under the truck and grab the drive shaft and turn it back and forth about 5-10 degrees. But the play that is there is not in the u-joints but rather it is coming from the rear end at the rear pinion gear from inside the pumpkin.

It almost feels like there is a huge amount of play between the rear ring and pinion gear where they mesh.

I thought i would ask if any of you have had this happen before of may be able to shed a little more light onto why it is suddenly making this clunking noise and drive shaft play. Thanks again for any ideas.

 

[blueflamed03]

have you crawled under to listen while someone goes from R to D, and vise versa?

 

[ravingmadman]

Holy poop dude, go get a $4 rear diff gasket, and open it up. Your rear pumpkin is probably about to go. The gov-locks are notorious for blowing up. Check out my profile pictures to see what it looks like post mortem... Best of luck!!!

 

[inkadink]

Yes blueflamed03, I did that today and crawled under the hoe. I was able to isolate the clunk sound coming from the rear end. The drive shaft had no play in the u-joints. There was no slack/slop in the drive train until it went into the rear end/rear pumpkin at the rear pinion.

---------- Post added at 09:14 PM ---------- Previous post was at 09:09 PM ----------

ravingmadman, I do have the G80 option as well. Man this can't be good

 

[inkadink]

Also,,,,This might be worth mentioning, I had my rear pinion seal replaced by a shop about 3 months ago. Do you think the rear pinion nut may have come loose to cause the sounds and symptoms I have mentioned?

 

[black95]

if the right torque spec was not place on the pinion shaft it could cause ring and pinion failure. you might not get very far, but go back to the shop and mention what happened, see what they say. sorry to hear about your issue

 

[bablurp]

sadly i just got something similar to this happening just yesterday... i come to a stop and i hear a clunking sound in the rear end.. i dont want to put more shop time on the tahoe

 

[blueflamed03]

sounds like it's time for a gasket/oil change and inspect rearend.

 

[ravingmadman]

Yeah, you know, as I was driving home last night, it donned on me it could also be your transfer case. But it looks like you already checked everything for play. But just a thought.

You definitely need to pull the cover off the diff, and get inside it, asap. When these things go, they go with a bang and you'll have to use your 4wd to drag your car, with the rear wheels locked, off the road. Pretty much the wost thing for your truck and manliness ever.

 

[Chevyrider619]

Hey INK..Did U end up finding what the problem is?? cause mannn!,I have the same problem right now too..that clank when you go from D to R...

 

[inkadink]

First of all I must Thank-you for all of your replies.

The clunk sound has happened so suddenly that I have elected to not drive my truck as past friday 10/11/09. I have the hoe parked right now in the lot of the shop who did my rear pinion seal a few months ago. They are going to look at it on monday and call me with what they find out. I sure as heck hope it is a loose rear pinion nut and not internal rear end pinion/ring gear failure. I will find out soon.

In response to Chevyrider619..... The clunk sound I am talking about may be your U-joints going bad. Failing u-joints will have the same sound. Other people here have also posted creditable responses in regards to why out trucks may be making these sounds. Crawl under your truck and lift up and down and back and forth on your rear drive shaft to see if there is any play/slop in that location. This can help you find out if it is the U-joints that are bad or if it is something other than that.

I will post back here once i find out what is going on with my hoe.

If anyone has any ideas/questions/answers/personal experiences regarding my issues please post. Thank you all

 

[Superman84]

i vote to being a loose pinion nut

 

[inkadink]

Sorry for the long delay. Here are the results of my issue from above.....

It was a loose pinion nut but the shop was kinda hesitant to actually say to me that it was their fault yada yada yada. I even told them when I dropped off the Hoe that I am "hoping" it is something simple like a loose rear pinion nut (hint hint).

Well they took off my rear differential cover and had look around too. They said the rear differential pin was worn and it would be wise to replace that because if that were to fail the rear diff. goes boom. So I allowed them to do that work too. They replaced the rear diff oil with synthetic 75-90 and a special friction additive for the G80 rear diff. They said there was a bulliten about having to do that and I understand that.

The key for me in figuring it out was because the clunking sounds happened soo suddenly and I just had my rear pinion seal replaced. Also, when I crawled under the truck and turned the drive shaft by hand there was about 10-15 degrees of rotational free play where the drive shaft entered the rear differential at the rear pinion. If you have ever seen how the ring and pinion gears mesh together it all makes perfect sense. The pinion nut became loose and allowed the rear pinion to move in and out ( clunk clunk) when I put the Hoe in drive and reverse. Thankfully I realized that immediately otherwise the rear pinion nut would've come off and the pinion hear would have fell into the rear end = junking my rear end.

Hope this may help other people out if they encounter something like this. Take care all and may you all have a happy new year

 

[Chevyrider619]

Well i'm glad it wasnt nothing major on ur ring,pinion...On my situation i haven't heard it but,like some guys were saying it could be the nut,u-joints or bad gears..I dont think it was bad gears or any of the above(changing lil the subject,sorry guys) if my u joints or any of them were bad i think they would've went everywhere this weekend i pulled my neighbor's 27'u-haul trk with all his house stuck deep in mud,grass..nothing happend,my baby pulled that big boy like a CHAMP! but i'm opening the rear wed. and taking a look inside just to be safe