[TrinDenise]

Hi guys. I just got back to Georgia from Ohio last night. After driving half the way home the truck started making a whining noise that seemed to come from the back of the suburban. It felt like the front wheels were gonna vibrate off until I reached a speed of 50mph. The vibration and noise would stop until I let off the accelerator and then it sounded as if something were grinding or crunching under the floor board. The sound was similar to what you hear when you wear down your brake pads to the metal. We stopped at a gas station and that's when I noticed an oily residue covering the back of the truck doors,windows and bumper. At first I thought it was transmission fluid but it's not. It looks like oil and kinda smells like it. I looked up under the truck this morning and the bottom of the car above the rear axle is covered in this oil mixture. Can anyone point me in the right direction of what the problem may be and what it will take for me to fix it? Did I blow a seal or just plain tear something up?
Thanks Trin

 

[tbplus10]

I suspect you blew the pinion seal or fluid was being blown out through the vent.
The reason, probably overheating of the axle.
The carrier and or pinion bearings were either getting bad and caused it to overheat or the axle was low on fluid causing it to overheat.
The repair, replace the rear seals, bearings, possibly gears, and possibly the brake shoes if the axle shaft seals leaked..
An alternative and possibly cheaper solution would be to find a wrecked low mileage truck or Suburban and swap in the whole axle.

 

[cao88c]

Hi guys. I just got back to Georgia from Ohio last night. After driving half the way home the truck started making a whining noise that seemed to come from the back of the suburban. It felt like the front wheels were gonna vibrate off until I reached a speed of 50mph. The vibration and noise would stop until I let off the accelerator and then it sounded as if something were grinding or crunching under the floor board. The sound was similar to what you hear when you wear down your brake pads to the metal. We stopped at a gas station and that's when I noticed an oily residue covering the back of the truck doors,windows and bumper. At first I thought it was transmission fluid but it's not. It looks like oil and kinda smells like it. I looked up under the truck this morning and the bottom of the car above the rear axle is covered in this oil mixture. Can anyone point me in the right direction of what the problem may be and what it will take for me to fix it? Did I blow a seal or just plain tear something up?
Thanks Trin

Check the axle seals on both sides. Most probably a bearing went out and caused the seal to break.

Also, open up the diff cover and make sure that there are no metal shards in there.

I CANT BELIEVE THAT YOU DROVE 1/2 WAY FROM OHIO TO GEORGIA LIKE THAT!!!:slap:

Reading the rest of your post, I'd check the spider gears in the carrier also.

 

[unplugged]

Yeah, I'd pull the diff cover too. If there is trouble in there I would go for a complete swap with a used unit. Freshen it up and you'll be back on the road in no time.

 

[TrinDenise]

Thanks Guys. I had a feeeling that was probably the problem. Okay now for the hard part. What is is your opinion on which way I should go to repair this? Buy all new parts and do it that way or buy a used axle from a junked suburban? How difficult is the repair if I do it myself and how long will it take? And do you have any suggestions where I should buy the parts from? I put new brakes shoes on about 3 months ago. It figures that I would have this problem now that its finally pouring the rain here in Georgia
Thanks for your help as always, it's appreciated.
Trin

 

[TrinDenise]

Any idea what axle assembly I have on this beast? Bolt pattern etc.?

 

[tbplus10]

Look on Craigslist and/or local wrecking yards for a whole axle assembly. You can use the axle from any 1500 series truck, van, Tahoe, or Suburban. Check the options you have on your truck before buying an axle, i.e. ABS, Traction Control, and gear ratio. The final gear ratio should be on the door plate.
Replacing the whole axle assembly will probably be cheaper and less hassle than stripping down your present axle, having new bearings pressed in, setting pinion preload, setting gear lash (if you need new gears), putting in new seals, and replacing whatever else may have gone bad.
I'm a pack rat so if the drums and shoes are good on the old axle I'd probably save them, along with any other smaller removable, useable items.

 

[TrinDenise]

Thanks. There is no doubt I tore the rear end up and busted something inside the housing. It is making the god awfullist noise. I looked on the door label and it doesn't have the gear ratio numbers on it. A guy spoke with at a salvage yeard said he couldn't get the number from the VIN and that I needed to get the stamped number off the axle assembly itself. Can you tell me where this is located?
thanks Trin

 

[tbplus10]

The gear ratio should be stamped or be on a tag attached to the rear gear housing.

Other resources are calling a local GM dealer parts counter and they should be able to use the VIN to tell you the gear ratio from the factory.

The factory build sticker in the glove box should have gear ratios listed.

Heres a VIN decoder I've used in the past that's given me factory ratios on some vehicles. http://www.analogx.com/contents/vinview.htm

 

[GaryL]

Look in the glove box and you will find a sticker with a bunch of letters and numbers. Find the "G" section and match it up to the list below to find out what rear end you have.

G80: Locking,Rear Axle
GH0: 3.54:1 Rear Axle Ratio
GT4: 3.73:1 Rear Axle Ratio
GT5: 4.10:1 Rear Axle Ratio
GU4: 3.08:1 Rear Axle Ratio
GU6: 3.42:1 Rear Axle Ratio