[sirfoulsalot]

New here, tranny question...

Hey everybody,,I'm now the proud owner of a 1995 Burban 1500 4WD.
I've wanted one of these for awhile,and this one came along at the right time. It's got a new Chevy 350 with less than 8000 miles,,but everything else has around 250,000 miles.

Driving around the other day, I started getting a low hum/vibration coming from the rear end while coasting. It doesnt do it while accelerating or under normal load,just when I let off on the gas.

Sounds like somebody driving next to me with really good,loud bass speakers. It is certainly more pronounced with more speed. Put it in neutral while coasting,no change. Has this happened to anyone else?

Would like to from some of you on here before I just go blindly to a mechanic.

Any help is greatly appreciated.
Thanks, Randy

 

[Davandy]

Sounds like U joints

 

[unplugged]

Ring and pinion?

Check the play in the u-joints asap. It is no fun to lose a driveshaft while at speed. I'm not sure that u-joints are your problem though. Under coasting the ring and pinion load changes, and the noise could be coming from there. Raise the rear wheels off the ground a set the rear axle on jack stands. Have someone operate the throttle switching between accelerating/coasting. Standing at the rear of the vehicle you should hear the sound and be able to isolate the noise. Keep us posted.

 

[MrShorty]

Pinion bearing or u-joints is where I would look first.

 

[sirfoulsalot]

Thanks for the quick response...
I went by a shop today and they said from what I described,,seemed like it would be the ring and pinion.

They said the parts kit could be around $200.00 and labor would be about $400.00
Did some research..seems like $200.00 for a ring and pinion kit is about right.

Is something like this that labor intensive?

I can't drop it off at a shop until Monday...should I not drive it this weekend?
Would I cause more damage?

Thanks again,,Randy

 

[dbledsoe]

Sounds reasonable for a '95. My '94 K1500 has had the rear end hum for some time. Nothing to worry about unless the hum drives you nuts. I'm waiting for mine to get bad enough that I can justify having it re-done, and then I'm going to switch to longer gears for better gas mileage. You probably have the 3.73 gears like I do. Changing to 3.08 or similar could increase gas mileage by 10-15% - assuming you can afford the power loss. I figure if I ever need a bunch of power I can switch it to 4wd-low range.
I'm at 225,000 miles now and I recently had the transmission changed out - and then had it changed out again because the GM replacement was defective. Fortunately, it was covered by the warranty the second time.
Right now I'm dealing with steering issues. It seems to wander all over the road. I guess the steering sector is worn out.

 

[MrShorty]

Setting up an R&P is pretty labor intensive. It's not necessarily difficult, but it requires very exacting measurements, some trial and error and such.

If you do want to change the gear ratio, be sure to recognize that, if you have 4WD, you also have to change the front. You can't have a different gear ratio in the front than you have in the back.

I don't know if it's the kind of thing you're interested in, but, if you do have to have the R&P set-up, nows the time to consider getting traction aids. If you have the G80 and want to get something better, or if you have an open carrier and want to get something better. I only mention because, if I ever had to pay someone to set up an R&P for me, I would really try to convince myself to pay a little more and get a locker.

 

[unplugged]

If you are considering a tire size change this would be the time to do it, because your gear ratio selection will be affected by a change in tire size. Here is a great chart on ratios/tire size. A lot of good info on gear swaps at: http://www.drivetrain.com/rearend.html

 

[sirfoulsalot]

Thanks for the advice and info.

I dont think I will go with bigger tires,I'm already on 33's.

I will make sure I go to a shop that understands gearing on trucks with oversized tires.

 

[sirfoulsalot]

UPDATE!!
Sorry it took me so long to post back on here with the solution.
But..I took it to a shop and had the U-joints replaced.
Solved all the problems!
Thanks again for all the advice and help!!
Randy