Growl when in reverse with brake applied...

[bullsnake]

Good evening everyone!
I've got an appointment to have my '96 looked at on Monday, but I was wondering if anyone else had run into this problem. After driving over to pick up some equipment in a little town about 60mi away and back home, I noticed that when I put it in reverse with the break applied I hear a growling noise coming from the transmission area until I let off the brake and everythings good. Runs out fine in drive and reverse works well too. I don't recall it making the noise before, but I have only had the vehicle a few weeks. We had a snowstorm here today and I had to drive it into town and it didn't seem to be as loud in reverse, and ran out fine. Just wondering if this is as bad as I think it's going to be...

[Yetti]

I am not sure as I haven't been under one in years but I would look at the rear trans mount to see if its in tact. the rubber might be torn out and its grounding againest the chassie.

[bullsnake]

Thanks Yetti!
I'll crawl under it this weekend and check it out. I am hoping it's something like this and not a trans. rebuild. Because of it's history with me I'm keepin' the truck no matter what, I just wasn't planning on something major right off the bat. Driving the truck for 2 1/2 hrs straight at sustained speeds of 70mph on the flat and level shouldn't kill this thing, right? I was watching the temp gage the whole time and it was always well within the 180 degree range.

What should a trans rebuild cost if that is the case? I just want to make sure I'm not gettin' hosed...

Thanks!

[phazer42]

I have had issues like this that were brake pad related... replacing the pads and no issues afterwards.....

[bullsnake]

Were your brakes pretty well worn? This truck has had new brakes 1800 mi. ago, but I have always noticed that they squeal a little the last 20-30' when I brake at a stop sign or light.

It's like this:
Put the Hummer in drive-runs like it always had.
Put the truck in reverse-runs like it always had.
Put the truck in reverse WITH the brakes applied, ie. not moving just sitting there stopped with gear selector in reverse and brakes applied=growling noise.

The trans mount seems to make a little sense to me in that if there was one that was toast putting it in reverse may cause the trans to shift under the torque load and come into contact with the frame or body, thus causing the noise. Once the brake is released torque is transferred through the driveline and growling stops.

[Yetti]

one of the other things to look at is the exhaust. if its touching the chassie it will do the same thing. if by chance you can block the drive wheels and have someone look under it while its in reverse you may have a better veiw of the noise or at least a closer area to look at when its off and you can get completely under it. DO NOT get under it with any body parts you can't afford to loose while its running. leave that for trained mechanics...(Thier expendable!)

use a pry bar to lever againest the exhaust pipe mounts and trans mount to see if they are torn. it doesn't take much effort if its torn so don't force anything if it doesn't move.