i think my rear end went out........

**TransAm11973** · 03-17-2008, 01:29 PM

so i was driving to the store and I stopped at a light and heard a strange loud clunk and grinding noise,...at first sounded like transmission......but I am thinking its the diff...it has been a bit clunky for some time but nothing like this....when i start up in first its very loud and then quiets down once in second gear but it is still louder than any clunk i had before. I was afraid I wasnt going to make it home. The noise is definately coming from the rear end so I was thinking its a u joint or diff, but i dont think a ujoint will sound like this. So I need some advice from those who have had their rears go out, BTW its the stock piece of shit too......do you guys think its the diff?? if its is whats the best route to have it replaced? does it make and sense toget new gears put in or do i need to do the whole rear end ????? Seriously in a bad mood, I woke up this am and had a feeling that something was gonna happen like this.....well it did.....i appreciate the help guys.

**JehalinTA** · 03-17-2008, 05:27 PM

I had a rear pinion seal go out...It was slightly leaking and I had a shop replace the pinion seal.. they over tightend the pinion which caused the seal to break... When I was driving I had the music up and heard a grinding sound and smelled something like burining tar.... The pinion seal had broke and all the rear diff. fluid leaked out. Basically the whole rear end was shot and I had the entire inside re- built. My advice to you would be to open the diff. fill plus and stick your pinky in there and see if there is fluid or any evidence of a leak. Bad news is.. if the rear end is making a grinding noise it will need repair... My rearend costed 1800 to fix (the shop that messed up paid for the repair). However, after having it rebuilt the rear end still was leaking... so I took it to a dealer and they still didnt fix the leak.. If the repair is more than just a basic seal I would recommend you get a jukn yard rear end and have them swap them.. Rebuilding them for some reason gives you more of a head ache. Hope that helps

**jcws6** · 03-20-2008, 07:17 PM

If I were you, I'd get the car up in the air & spin the rear tires while in neutral. Then you can lay under there & hopefully hear what's making noise. If it turns out to be a differential, my vote is for complete rear end if you can spare the cash. If you decide to get yours rebuilt, figure about $300 for the job from a reputable rear end shop + whatever parts you need.

**PFM** · 03-21-2008, 05:16 AM

I hope your smart enough to have AAA. Your going to need it real soo I'm afraid!

**TransAm11973** · 03-21-2008, 10:50 AM

i havent driven the car since i got it home, i have been driving my DD. Looks like the trans am wont be on the road for a while. Been very busy with work but I am going to go and lift it up and check it out now and go from there....any other help would be great I will let you guys know whats up

**TransAm11973** · 03-21-2008, 12:25 PM

Originally Posted by jcws6

If I were you, I'd get the car up in the air & spin the rear tires while in neutral. Then you can lay under there & hopefully hear what's making noise. If it turns out to be a differential, my vote is for complete rear end if you can spare the cash. If you decide to get yours rebuilt, figure about $300 for the job from a reputable rear end shop + whatever parts you need.

well i hhad it up in the air and was rotating the rear, i go NO extra noise or clunking, so then i drove it around the neighborhood and all the clunking etc was back. Although this time I didnt have the horrible grinding . I decided not to take off the plate.....i think its a waste of time b/c I ampretty sure the differential has to go. Well now I need to know how much those who have had a rebuild done spent and if they reccomend it...or a all new rear end..

**jcws6** · 03-21-2008, 02:21 PM

You might not be as screwed as you think. Is the clunking noise speed-dependent (faster clunking when you drive faster)? Does it happen at any speed, in any drive gear? If so, it might just be a bad u-joint.

A few years ago, I rebuilt the rear end in my GMC Jimmy, which has a similar rear axle. I only replaced the differential unit itself, though. I put a new Auburn posi in there, which was about $350 from ebay + around $100 for a rebuild kit (bearings, crush sleeve, gasket, bolts, etc.) + $50 for fluid & "miscellaneous." I would NOT recommend trying a job like this on your own, though, since it requires a lot of specialized tools & knowledge. But the rebuild cost probably depends on what you need replaced back there. I'd estimate upwards of $1000 to have a good rear end shop do it if you bought the parts on your own.

Coincidentally, about 18 months and 30,000 miles later, the cross-shaft retaining bolt in my rebuilt rear worked itself loose & the whole thing grenaded (yes, it was torqued to service manual specs). Damn.

**TransAm11973** · 03-21-2008, 05:35 PM

i looked at my u-joints today they looked fine....well my diff was always kinda clunky and it was know to me that it was on its way out but wasnt horrible. now i get grinding in first gear, and the ass end is much louder sounds like there is shit just clunking inside the pumpkin......i did have it up on jacks today and was rotating the rear myslef and couldnt remake the noise but as soon as normal driving pressures are put on the drive train it comes back, i mean literally it sounds "loose" of that makes sense but everything its tight, joint bolts, suspension etc

**edbird** · 03-22-2008, 03:16 AM

Did you take the plug out and stick your pinky in to see if you actually have fluid?If it were me, and I had fluid,I would undo the u joint and inspect the bearings for wear-it should be obvious if thats your problem.If that checks ok,I would pull the cover off and see what falls out!Seen lots of pics of gear teeth broke off.
Up to now,this has all been simple checks that need to be made before you condem the rear end.If gears are broke,and it were me ,i would not have it repaired as these rears have a history of being weak and will break again.If I wasn't ready to spring for a Moser or Strange(around 1800.00) I would look for a complete used rear.You usually see them in for sale forums for 200.00 to300.00 bucks pick up only.
Thats what I would do-hope this helps and Good Luck!

**sunsetorangess** · 03-22-2008, 06:43 AM

Picking up a used rear end in my opinion is a bad idea. You really dont know the condition, I would pop the plate and take a look, chances are when you pull the plate you will have chuncks in it. I knew a guy that drove his for about a year on a clunky rear, It was horrible, you could be a mile away and hear him coming but he didnt want to replace it.
If you dont want to pull the plate atleast pull the plug and make sure you have fluid in there.
J

**TransAm11973** · 03-22-2008, 08:36 AM

yea i got plenty of fluid in there. Iwill pull the plate off one of these days but i am in no hury b/c i am not going to drive it any way and i need to save up a bit to fix whatever has to be done