Rear End trouble

**wooddaniel** · 12-03-2010, 10:31 AM

My wife's car is making a thunking sound coming from the rear end when I accelerate hard from a stop, accelerate while turning, and when shifting into 2nd at WOT (Auto car with a stock 4l60E) I took the diff cover off, looks ok I guess, but there are some wierd shiny spots on some of the gears, IE it looks as if it's been wearing funny. The halfshaft coming from the pumpkin on the right side is also loose; there is play in it and I can move it by hand freely. Is there a clip that is internal that holds the halfshaft in place? The U joints appear to be fine as far as I can tell. The left side is tight and cannot be moved back and forth by hand. Any suggestions?

**Fester801** · 12-03-2010, 03:26 PM

Check the tranny mount. They are usually the culprit. I know it sounds like the rearend, but in my experience that is the first to go.

**wooddaniel** · 12-04-2010, 03:58 AM

Originally Posted by Fester801

Check the tranny mount. They are usually the culprit. I know it sounds like the rearend, but in my experience that is the first to go.

But should the halfshaft/CV whatever its called be loose like it is? Do I need new CV Axles is that the issue? My knowledge of IRS is not good.

**Texas Jack** · 12-04-2010, 06:32 AM

Are you talking shaft that goes from the wheel to the rear end, if so how much does it move. Jack

**wooddaniel** · 12-04-2010, 06:35 AM

Originally Posted by Texas Jack

Are you talking shaft that goes from the wheel to the rear end, if so how much does it move. Jack

I can't pull it out of the pumpkin, but it moves about an inch to 1.5.

**Texas Jack** · 12-04-2010, 06:43 AM

That is your rear axle shaft and they are weak, have you pulled the rear cover off yet. Sounds like it's failed.

**wooddaniel** · 12-04-2010, 06:45 AM

Originally Posted by Texas Jack

That is your rear axle shaft and they are weak, have you pulled the rear cover off yet. Sounds like it's failed.

Cover has been off. Insides look fine, and no whining or vibration just the clunking sound. I took the cover off Monday and changed the fluid hoping that would be it. So what do I need to fix this?

**Texas Jack** · 12-04-2010, 07:05 AM

It's called an axle stub and East Texas Muscle, and BMR suspension sell performace ones, take a look at those guys and you will understand what is going on. To make sure you will have to take the CV loose from the shaft that goes into the rear and pull it out, and that will tell the story. To pull it out it has a C clip on it.

**wooddaniel** · 12-04-2010, 07:18 AM

Originally Posted by Texas Jack

It's called an axle stub and East Texas Muscle, and BMR suspension sell performace ones, take a look at those guys and you will understand what is going on. To make sure you will have to take the CV loose from the shaft that goes into the rear and pull it out, and that will tell the story. To pull it out it has a C clip on it.

Thanks for the help. Damn it I just took it off the jack stands yesterday lol.

**Texas Jack** · 12-04-2010, 07:19 AM

No problem, Good luck!

**wooddaniel** · 12-04-2010, 07:21 AM

Originally Posted by Texas Jack

No problem, Good luck!

Thanks, Im hoping this is the only problem and nothing is wrong with the rear end itself.

**Texas Jack** · 12-04-2010, 07:34 AM

Originally Posted by wooddaniel

Thanks, Im hoping this is the only problem and nothing is wrong with the rear end itself.

Me too, Maybe it's just the axle stub on that side.

**wooddaniel** · 12-04-2010, 07:42 AM

Originally Posted by Texas Jack

Me too, Maybe it's just the axle stub on that side.

The noise is most definitely coming from the right side. I just drove the car again a minute ago.

**Texas Jack** · 12-04-2010, 08:06 AM

Make sure when you put new fluid in you add the limited slip additive to or it will chatter like crasy, get it from GM, and by the way that stuff smells really bad!

**wooddaniel** · 12-04-2010, 08:18 AM

Originally Posted by Texas Jack

Make sure when you put new fluid in you add the limited slip additive to or it will chatter like crasy, get it from GM, and by the way that stuff smells really bad!

Shit, I used mobil 1 synthetic fluid that said on the package it was for limited slip is that stuff ok???

**Texas Jack** · 12-04-2010, 08:46 AM

I used the GM stuff with RP so I don't know, didn't want to take any chances.

**wooddaniel** · 12-04-2010, 08:58 AM

Originally Posted by Texas Jack

I used the GM stuff with RP so I don't know, didn't want to take any chances.

Ill buy some of that stuff then. It's all coming right back out anyways.

**Texas Jack** · 12-04-2010, 09:06 AM

Hope it goes good for you!!!

**derbs** · 12-04-2010, 01:47 PM

Originally Posted by Texas Jack

It's called an axle stub and East Texas Muscle, and BMR suspension sell performace ones, take a look at those guys and you will understand what is going on. To make sure you will have to take the CV loose from the shaft that goes into the rear and pull it out, and that will tell the story. To pull it out it has a C clip on it.

BMR doesn't do the axle stubs and axles anymore. BMR is now having Gforce1320 make everything if you can't bet the best join them.