GM Truck Club Forum banner

1 - 20 of 32 Posts

·
Registered
Joined
·
23 Posts
Discussion Starter #1
Ok, so I have a 01 silverado, a couple of weeks ago I'm leaving work heading for home, just as soon as I hit the highway, I hear a god awful grinding noise, and I'm pressing the gas and not moving. So long story short I somehow got it off the road and had it towed it home. At home as soon as I put it in gear the grinding noise returns, so I crawl under it and have the old lady put it in drive, to me it sounds like it's coming from the transfer case. So I pull the thing out take it all apart down to little pieces, and cannot find anything wrong with it, no spun bearings, no stripped gears, input shaft splines look great on both ends... Put it all back in and viola it works fine! So I go to take it for a test drive down the street and as soon as I stop and go to take off again, the grinding noise returns, I'm not moving anymore and I have to walk back up the street and drag the damn thing home again!! What the heck can the problem be?? The part that really gets me is that when it breaks it doesn't matter what range the transfer case is in, I'm not going anywhere. I'm almost certain it's not the transmission because when it does work without the grinding noise I have tons of power, and I've ruined my fair share of automatic transmissions and have never ever heard grinding come from them! But it seems like when it starts grinding if I cycle through the ranges on the transfer case it will fix itself. From the times I've done it, all I did was shift the transfer case into neutral and then back into 2wd. The only thing I can even remotely come up with is that maybe the motor for shifting through the ranges isn't quite shifting completely in between each range, and the transfer case is getting hung up between two ranges. Or maybe the torque converter is broken somehow and it catches sometimes and works fine and other times it's just spinning. I'm totally lost on what the problem could be, and I can't really afford to take it in to have someone else tell me what's wrong with it. Anyone have any ideas or suggestions???? PLEASE HELP!!
 

·
Premium Member
Joined
·
1,625 Posts
Auto Tranies don’t have gears, they have clutches. So chances that it is the trany are slim.

First are you running it in 4 wheel drive on dry pavement? that’s a no no to begin with.

Is it possible it is the rear end?

Is the rear driveshaft turning when the noise is heard?

It may be in the transfer because you get it to work when you shift it in and out of 4 wheel drive but then I am not there.

It could also be in the axels.

Any more info?
 

·
Registered
Joined
·
23 Posts
Discussion Starter #3
Not running it in in 4wd on dry pavement, and i really don't think it's the rearend because when i breaks and I try to get the thing to move at all it doesn't matter if I am in 2wd or 4 it just plain won't go. The only time I ever use 4wd is in the snow and ice and pulling out logs to cut up for firewood, which is what I was doing shortly before it started doing this and it's not really a grinding noise more of like 2 gears not meshing together almost like the transfer case is stuck in between 2 ranges. At one point it wasn't making the noise but still wouldn't move, but if I feathered the throttle it was almost like when I first tapped the gas it would catch something and move, not fast by any means felt almost like it would if the tranny was slipping.... I'm still baffled
 

·
Premium Member
Joined
·
1,625 Posts
Pull the dipstick on the trany, if it smells like burnt almonds the trany is toast.

Sounds more like the transfer is getting caught between ranges.

I’m really not the one to answer questions about that.

Hopefully someone will pipe in that is more familiar with the newer transfer cases.

The only one I have ever had apart was the one in my old yard plow, 79 GMC with fulltime 4 wheel drive. I swear the thing weights more than the engine.

But this will give you a free bump to someone who has more knowledge about your transfer case.
 

·
Registered
Joined
·
23 Posts
Discussion Starter #5
That is the first thing that I did to the truck when it broke, hell I even pulled the pan looking for big chunks in there but there was nothing, fluid looked old but didn't smell burnt at all. So I changed the filter and put fresh fluid in it. And of course that did nothing. But I thank you for the ideas, I too am hoping someone will pipe in!!
 

·
Premium Member
Joined
·
1,625 Posts
Transfer case has got to be it then.

Maybe in between gears, again I am not familiar with the newer ones so I am hoping someone who is can give you some light on this problem, I do have to go to the garage first thing this morning and will get my manual and see if there is any info on the newer transfers.
 

·
Registered
Joined
·
233 Posts
does by any chance your truck only feel like its grinding from one side, i had a ram come in the other day, complaining that sometimes, it felt like the brakes were being applied but only to one wheel... and he use to hear grinding noises as well, but he thought since hes had the issue for so long, he grinded whatever was grinded down because it wouldnt make the grinding noise nemore, so we pulled everything off, everything, couldnt find the problem, in the end, it was a wheel bearing, the bearings were so gone that they were turning sideways, (cylinder type bearings not round) and as he was driving they would grind up untill he grinded each one except one down to barely anything.
 

·
Registered
Joined
·
23 Posts
Discussion Starter #9
It's definitely not grinding only on one side, it's straight in the middle of the truck. It's not really even a grinding noise, more like gears not meshing together. Almost like when you would shift the transfer case to neutral with the motor running and put the truck in gear, to me it sounds almost exactly like that. Like I said before what gets me is that I have pulled the transfer case and took it completely apart and don't see anything wrong with it at all. Which leads me to believe that maybe the motor for the shifter is screwy and maybe when it's bolted onto the transfer case that it is off just enough that it is holding the case in between 2 ranges. Any ideas?
 

·
Premium Member
Joined
·
1,625 Posts
Sorry for the delay on getting back to this. I had to help a friend put in some windows in a new house he is building.

I looked at my manual, it does not cover the 01 just up to 2000. But anyway.

The only thing I found was 54 a metallic grating noise consistent with vehicle speed.

U-joints.

But if it does this when it’s not moving you can forget about that.

There is no real info on the transfer case..
 

·
Registered
Joined
·
15 Posts
i had a 00 silvy do the same thing, replaced the shift motor thingy, and it solved it, the gears were not meshing like they were supposed to be. it's worth look at replacing that and see if it solves it. and when you had it apart, how did the keys look? or the Output spline on the trans, was it ok?
 

·
Registered
Joined
·
533 Posts
make sure the dipstick is not up against the firewall it has to be away from it
 

·
Registered
Joined
·
23 Posts
Discussion Starter #14
The keys looked fine, the output on the trans also looked fine. I am almost totally convinced now that it has to be the shift motor. I live in washington state so the next day that I get without rain I'm going to put the transfer case back in and not put the shift motor on it and see what happens, if I can drive it around with no problems then I'll replace it. That has to be the problem!
 

·
Registered
Joined
·
23 Posts
Discussion Starter #16
well it sounds almost like what mine is doing expect that when mine does it, the truck won't move at all, no matter what range it is shifted into. Tore the transfer case apart and no broken snap ring, which I thought for sure must be the problem. A lot of other threads talk about the buttons for shifting being faulty but all of them say they get a check 4wd error message and I am getting nothing from the message display. Which leads me to believe that it is mechanical.
 

·
Registered
Joined
·
23 Posts
Discussion Starter #17
UPDATE!

Ok well went out tonight and put the transfer case back in put everything all back together, hopped in it started her up, put it in gear and NOTHING, surprise surprise. I did install it completely without the shifter on it or even hooked up. I'm totally lost now, the transfer case on the inside was fine, obviously the shifter isn't the problem and yet I still have nothing. Any ideas at all, I did jack the rear end off the ground and with no load on it at all the tires spin, everything works great, but the instant it goes on the ground and has to move something I'm not going anywhere! Maybe tranny??? almost like it's stuck in 4th gear so it doesn't want to move?? no clue... Anyone?
 

·
Registered
Joined
·
23 Posts
Discussion Starter #18
Well now that I have had some time to cool off since this is the second time I've pulled the transfer case and reinstalled it to avail, I'm thinking that maybe it's the torque converter staying locked up for some reason, or maybe even a bad shift solenoid. Still trying to figure out the grinding noise. Didn't make any noise at all today though, just wouldn't go anywhere, if you kinda goose the throttle real quick it's almost like something catches and it really wants to go but that's about all I can get out of it, almost like the tranny is slipping and it seems like if it were rolling already and you stayed on the gas it would sort of catch up with itself and just keep on going. I have no idea, maybe I am just missing something inside the transfer case, but the tranny is making a whining noise almost it doesn't have a load on it, and it's just kind of spinning freely. I really wish I could explain it better. Oh, one other thing, when it's in gear and I'm trying to go the driveline isn't spinning at all and the speedo isn't going anywhere either, so the gear inside the transfer case that is right after the input from the transmission isn't spinning, which makes me think I need to look at the tranny, what's weird is that the times when it does just magically work, I have tons of power like nothing in the world is wrong, I have pulled the pan on the tranny and didn't find any big chunks or anything that would make me think that it is the tranny at fault so I'm just guessing that something with the torque converter or something electrical inside the tranny is to blame. It does seem like before all of this happened when you shifted the tranny into gear it made a definite "clunk" to let you know it was in gear now no "clunk" no nothing. I'm really just digging for a answer here and hopefully someone can help!
 

·
Registered
Joined
·
23 Posts
Discussion Starter #19
Weird...

:neutral: Ok so now it gets weird, this morning I pulled the hot rod out of the shop and figured I would tow the truck in to tear it apart again. Just for the hell of it I start it up, put it in gear and hear a grrrrrrr, thunk! Magically it works now, so I'm guessing that I am just missing something in the transfer case. Hell I even pushed my luck and drove it around the block with no problems at all. I've never rebuilt a transfer case before but when I tore into it I couldn't find anything at all that looked like it was worn or broken, possibly the synchro? Maybe someone who has rebuilt one of these things can give me some insight of what I should be looking for. One thing is for sure though I'm getting pretty darn good at pulling the transfer case and putting it back in!!
 
1 - 20 of 32 Posts
Top