Is my rearend going out?

**bcoffman** · 06-09-2009, 07:47 PM

I just got my 89 suburban 4x4 two weeks ago and now it is making a noise in the rearend.

It has a thump about 3 or 4 times when I take off, but not always. only does once and a while. I notice it more when i tow or gone up a steep hill.And more so when i take off easy. If I give it more gas on the take off it won't do it. It will do it backing and forwards. it also sound like it is coming from the left rear tire/wheel. It has new u-joints . I pulled the drive shaft out and greased it & slid it back in. I'm going to take the differential cover off and look at the gears , does anyone know what I should look for? I don't know if it is limited slip but could it be that? thanks for the help in advance.

**TRPLXL2** · 06-09-2009, 07:54 PM

I know this probably won't help you, bet here goes nothing. I have a 2001 S-10 with 3.23 gears in the back, I have blown two rear ends in the last 8 years from abnormal abuse. (Hole shots) Each time it happened I would get a roaring noise from the back of the truck, almost like a bearing was going out. The first time the actual teeth of the gears were completely ground down flat, the second time the pinion gear snapped in half and cracked a bunch of teeth. After the roaring noises I would here a quick "clink, clank, BOOM, POP!" And then the truck would coast to a stop, just my experiences but my truck is a lot newer than yours too.

**bcoffman** · 06-09-2009, 07:58 PM

It has me stumped because 80% of the time it is normal it is the other times I'm worried about.

**Jimmiee** · 06-09-2009, 08:01 PM

You need to pull the cover off and inspect it pronto. You may be able to salvage your carrier and or ring and pinion if one of your spider or side gears is broken. If you have a G80 it may be coming apart as well. Quit driving it if you want to save some money.

**bcoffman** · 06-09-2009, 08:06 PM

Thanks I am going to take it apart tomorrow. I don't see any tags on the rear how do I know what it has?

**Jimmiee** · 06-09-2009, 08:15 PM

Originally Posted by bcoffman

Thanks I am going to take it apart tomorrow. I don't see any tags on the rear how do I know what it has?

Once you get the cover off you can see if it's open or if its a posi or G80. If you have a G80 in the RPO code list in your glove box it's a posi. If not, it's an open diff.

**bcoffman** · 06-09-2009, 09:25 PM

Thanks I let you know what i find out.

**bcoffman** · 06-09-2009, 09:30 PM

Originally Posted by Jimmiee

Once you get the cover off you can see if it's open or if its a posi or G80. If you have a G80 in the RPO code list in your glove box it's a posi. If not, it's an open diff.

I don't have rpo on the list so it must not be posi. Thanks

**5speedsilverado** · 06-09-2009, 10:42 PM

Originally Posted by TRPLXL2

I know this probably won't help you, bet here goes nothing. I have a 2001 S-10 with 3.23 gears in the back, I have blown two rear ends in the last 8 years from abnormal abuse. (Hole shots) Each time it happened I would get a roaring noise from the back of the truck, almost like a bearing was going out. The first time the actual teeth of the gears were completely ground down flat, the second time the pinion gear snapped in half and cracked a bunch of teeth. After the roaring noises I would here a quick "clink, clank, BOOM, POP!" And then the truck would coast to a stop, just my experiences but my truck is a lot newer than yours too.

could you explain what you mean by hole shots? that also made me laugh a little

**TRPLXL2** · 06-10-2009, 08:31 AM

5 speedsilverado I see you have a dirty mind, I knew I would give someone a good laugh with that one. In 1/4 mile drag racing, when the christmas tree lights up green you try and take the whole shot and get out in front of the other guy right away. Or at a stop light when your foot is on the brake and your waiting, as soon as the light turns green you let off the brake and hammer the gas real hard. What it does is force the driveshaft back into the pumpkin (rear end), and that's basically what a hole shot is. Most people I race take a slight hesitation at the start to avoid this, but I race like I stole it and that's why I blow rear ends like that. My dad said if I do it again, he is going to put a Ford 9" rear end in it and then he said I won't be able to blow the rear end any more.