• If you currently own, previously owned or want to own an Avalanche, we welcome you to become a member today. Membership is FREE, register now!

Grinding in 4WD Hi?

M

Mexican_Menace

Full Member
Joined
Aug 23, 2002
Messages
101
Location
Irving, TX
Last night it was raining pretty bad. I put my 2002 Z71 AV into 4WD Hi as I had had problems with my local streets and fishtailing in the rain a couple a days ago. I started hearing a grinding kind of sound. I figured it was the road as I was on until I got a to a new, smooth patch of pavement and the sound continued.

I got to my friend's apartment and had a hard time turning into a parking spot. I got out and nothing seemed noticably wrong, but when we backed out, the truck would barely move. I put it back into 2WD Hi and everything was back to normal.

Any ideas what could be up with my 4WD? I've got 37,000 miles on it and never had a problem with 4WD until last night, even in the snow & ice we had here last year.

Is this the problem covered in the thread Major 4WD Problems?

Thanks.
 
When i purchased my 91 S10 4x4 there was a tape in the glove box about when and how to the four wheel drive it said to use the four wheel when raining but when the rain stoped to switch back to two wheel drive as there was not enought slippige on dry or not so wet pavement, for the front tires, and from exerpience the same holds true for the Avalanche.
With my 02 Z71 when raining i use the AWD Button, yor still have some feed back from the front wheels but not as much as when in four wheel drive turning corners
Just my nickles worth
;D ;D
 
Mine has some noise in 4 wheel hi and does not turn well on anything but slick pavement. Even when snow and ice are present I only use it in situations that are pretty extreme. Otherwise I keep it in auto 4 wheel drive which takes care of the bulk of conditions.
 
4Lo works great on pavement in the hot summer days. When you have the wheels cranked, it will tear up some of the pavement!
Just glad is wasn't my driveway!
 
dichris said:
4Lo works great on pavement in the hot summer days. When you have the wheels cranked, it will tear up some of the pavement!
Just glad is wasn't my driveway!
Click to expand...
I'm going to assume this is an attempt at humor. Problem is, some people may not get it and could damage their vehicle. If you're not joking, then I respectfully suggest that you go read your manual.

MexicanMenace, assuming you're not joking, the answer is easy...do not drive your Av in 4-wheel drive on the pavement, rain or not. It wasn't designed for that.

Rich :)
 
Ack! You shouldn't use 4WD unless things are really nasty out. The differentials have a hard time when engaged allowing things to spin properly. The grinding noise and problems with hard turning are all "normal." Short term this won't cause damage to your drive line but do more and you'll have problems. If things are really bad enough for rain AutoTrac is all you need, however you'll still have the issue with tight turns.

4WD should only be used on slick surfaces like snow, mud, and ice or when you are off-roading. Even off-roading I use this rule of thumb:

2WD until I need AutoTrac

AutoTrac until I need 4WD

4WD only when I need it back back to AutoTrac

4Lo to get me out of problems if I get stuck in 4WD. I've only needed the tow strap once!
 
Driving in 4X4 should only be done on loose surfaces such as unpaved roads(dirt) or snow covered roads. The reason your truck locked up and wouldn't move when you were backing out of the parking spot is because everything was bound up. I use my auto track like hot butons here in AK. Portions of the road may be icey and then dry. Never drive on dry pavement in 4X4. I don't even use it when it rains. I guess our roads are not very slippery when it does rain. As for the noise, is this the first time you have driven on non-slippery surfaces in 4X4?
 
Gotcha. I talked with a buddy yesterday and he said the same thing re: rain (he's got an AV as well). I'd only flipped it on during heavy rain once before and I never heard the grinding or had problems turning that I'd noticed. Last time I used 4WD was when it snowed and iced over out here last year (my buddy and I were the only two that made it to work that day).

Guess I know better now. Thanks all.
 
RichUF said:
dichris said:
4Lo works great on pavement in the hot summer days. When you have the wheels cranked, it will tear up some of the pavement!
Just glad is wasn't my driveway!
Click to expand...
I'm going to assume this is an attempt at humor. Problem is, some people may not get it and could damage their vehicle. If you're not joking, then I respectfully suggest that you go read your manual.

Rich :)
Click to expand...

Yes this is a little bit of humour, however that being said I did experience this as I had the AV in low range to pull some shrubs out ( AV was on yard ) but forgot to take it out of 4Lo when I went to turn on the driveway.... Weakest link was the pavement.. Not pretty.... Good thing the driveway was being repaved later that month....
 
Bought my 2002 Avalanche Northface 3 months ago. Went off warranty about a month ago (39,000 now). Been using 4HI alot due to local conditions. Immediately noticed grinding noise from both sides front, especially turning. Went to local dealer--mechanic told me it was normal (yeah right). Religious Chevy fan told me no way. Went back to seller (good local used car dealer) who took it back to the local GM dealer service (same one I had gone to). They agree to replace ring gear, pinions, side bearings, and pinion bearings (reciept states all repairs done as "good will" no charge). They had the truck a week. Got it back and a day later it makes the same grinding noise as before (though not constant and again especially audible in turns and when slowing down).

Now what do I do? Local mechanic told me that GM has sent a bulletin out on this problem.
 
I also have a grinding/vibrating noise in Auto. At speeds above 60 mph, when I hit the Auto button, the ?transfer case? grinds on and off in a kinda 'wow wow wow' sorta way. Below 60 mph and the works aren't spinning fast enough to make this noise. Above 70 mph and I think the driveline is falling out! My '01 Silverado did not make these noises at 70 mph in Auto.

I did try going to 4 HI and the noise was exactly the same. Anything above 60 mph and it's bothersome. I've thought of running my truck at 80 mph in Auto until something blows up, then use the Onstar to have it towed to my dealer for free ;D
 
You must log in or register to reply here.
Back
Top