05 front diff or t case grinding noise after rotating tires
February 9th, 2010, 10:02 AM
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05 front diff or t case grinding noise after rotating tires
MY 05 Z71 has the auto T case, and does have autotrackII fluid in it, the front diff oil is full, neither one has any metal shavings in the oil,
I checked the rollout difference of the tires and they are all within 1/4" of each other.- im picky with this being used to having AWD cars that the tires have to match.
the rears were worn barely more than the front, and never heard a sound from the drivetrain.
now that the rear seems to be pushing slightly more than the front I have a pretty nasty sounding dry bearing / buzzing grinding noise when the 4x4 is on, even when the road is completely covered in snow. When its in auto 4x4 you can hear it as it turns on and off, and it sounds about the speed of the front driveshaft. IF im hard on the gas its silent, steady speed / decel it gets pretty loud and it changes hitting bumps, but no difference if the road is dry or snow covered. the 4x4 does work just fine, its just noisy all of the sudden, i havent seen anything visually wrong externally.... I do drivetrain componets, transmissions and differentials for a living and this one has me kinda stumped as to whats making all the racket, doesnt it in hi or low range and varies with wheel speed, and is for sure front driveshaft speed related, doesnt sound anything close to ring and pinion whine.
anyone have any idea? maybe the coast side of a gear in the T case? If any of you have heard the funny gear whirling sound when you turn a corner in 4x4 coasting that most of them make, its very similar to that.
I checked the rollout difference of the tires and they are all within 1/4" of each other.- im picky with this being used to having AWD cars that the tires have to match.
the rears were worn barely more than the front, and never heard a sound from the drivetrain.
now that the rear seems to be pushing slightly more than the front I have a pretty nasty sounding dry bearing / buzzing grinding noise when the 4x4 is on, even when the road is completely covered in snow. When its in auto 4x4 you can hear it as it turns on and off, and it sounds about the speed of the front driveshaft. IF im hard on the gas its silent, steady speed / decel it gets pretty loud and it changes hitting bumps, but no difference if the road is dry or snow covered. the 4x4 does work just fine, its just noisy all of the sudden, i havent seen anything visually wrong externally.... I do drivetrain componets, transmissions and differentials for a living and this one has me kinda stumped as to whats making all the racket, doesnt it in hi or low range and varies with wheel speed, and is for sure front driveshaft speed related, doesnt sound anything close to ring and pinion whine.
anyone have any idea? maybe the coast side of a gear in the T case? If any of you have heard the funny gear whirling sound when you turn a corner in 4x4 coasting that most of them make, its very similar to that.
Last edited by racerx55; February 9th, 2010 at 10:08 AM.
February 9th, 2010, 10:16 AM
#2
probably just a tire.. i had a tire doing this BEFOR i rotated. it stoped when i rotated. so you probably just got a tire thats wareing uneven or mine had the weird lump all the way around the tire in the middle of it.. i cant think of the word.. lol..and it was vibrating.. but if u do this for a living it could be other things i dont much about t-cases or front diff to tell u anything about them. what u could do is rotate them back.. see if that clears it up then you would know its a tire
February 9th, 2010, 10:21 AM
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it sounds like there is a trash can jammed in the front driveshaft and it silent in 2wd also, when you push the 2wd button you hear it slow down and quit.. i shoulda bought a jeep.
Tires are quiet as can be for what they are up to 100mph, im afraid to go over 30mph in 4x4 from the noise lol. its loud enough it makes people turn and look, maybe i will take a video later and post.
Tires are quiet as can be for what they are up to 100mph, im afraid to go over 30mph in 4x4 from the noise lol. its loud enough it makes people turn and look, maybe i will take a video later and post.
February 9th, 2010, 11:08 PM
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try pulling on the pinion the should be no end play and minimal side to side play, same with the transfer case, also compare the wheel bearings if one side is warmer to the touch than the other side id be suspisous off them then, you could drive in reverse to eliminate the coast side of your gears, did you check the slip yoke on your drive shaft?
February 10th, 2010, 3:16 AM
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Front diff checks out fine, no noticeable bad T case input / output bearings.
Removed the front driveshaft and ran it on the lift, the noise is still audible in 4wd, but gone in 2wd....in auto 4wd with the driveshaft on it comes and goes as the clutch goes on and off to match the wheel speeds. maybe the bearing for the clutch pack actuator?something is wrong in that area i belive. its definately in the T case. Once the snow is done being 3 feet deep ill pull the t case apart and see what i find unless it blows apart before then.
Must have just happened right before or after i rotated tires but that seems to have nothing to do with it.
I have noticed recently while in 2wd and full throttle from about 60-80mph a slight vibration feeling like a driveshaft out of balance, now putting that all together and going over an exploded veiw of the NV246 t case im thinking a bearing is coming apart in the t case somewhere, yesterday it sounded like a gear grinding into the aluminum housing and now its getting quiet again,and the auto 4x4 seems to be engaging a bit more violently than normal. but i still dont see any metal in the t case oil.
the noise is gone accelerating, and louder on decel, over bumps it comes and goes.
Removed the front driveshaft and ran it on the lift, the noise is still audible in 4wd, but gone in 2wd....in auto 4wd with the driveshaft on it comes and goes as the clutch goes on and off to match the wheel speeds. maybe the bearing for the clutch pack actuator?something is wrong in that area i belive. its definately in the T case. Once the snow is done being 3 feet deep ill pull the t case apart and see what i find unless it blows apart before then.
Must have just happened right before or after i rotated tires but that seems to have nothing to do with it.
I have noticed recently while in 2wd and full throttle from about 60-80mph a slight vibration feeling like a driveshaft out of balance, now putting that all together and going over an exploded veiw of the NV246 t case im thinking a bearing is coming apart in the t case somewhere, yesterday it sounded like a gear grinding into the aluminum housing and now its getting quiet again,and the auto 4x4 seems to be engaging a bit more violently than normal. but i still dont see any metal in the t case oil.
the noise is gone accelerating, and louder on decel, over bumps it comes and goes.
Last edited by racerx55; February 10th, 2010 at 3:29 AM.
February 10th, 2010, 10:39 AM
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February 12th, 2010, 10:10 AM
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Let me know what you find out. I'm having the same problem only I put a Rough Country 3" lift on the front. That required me to put diff spacers and strut spacers on. It was installed at 1,200 mi and the 4WD worked/sounded fine then. Now, with all the east coast snow, at 60k mi I am hearing the noise. Mine might be low fluid but I haven't checked yet. I have been driving my wife's H3. I did go under the truck and tried shake things around but everything seemed pretty solid. Let us know what you discover. Thanks.
February 12th, 2010, 11:22 AM
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I have one doing the same thing and when you barely turn the wheel left or right you get that hop. The same hop when you go full right or left. At slow speed in 4wd it also slows as if you were stepping on the brakes. The only thing I can see is with the driveline off i can rotate the pinion back and forth about 2" before making contact with the ring. I'll take some tips if anyone has some.
February 12th, 2010, 9:07 PM
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check your tires, if they are not exaclty the same make,,model, tread pattern and tread worn close to the same, it will cause it to bind up and make noise. and it gets very loud.
In the past i had bridgestone dueler AT, i put 2 half worn out dueler AT revo's on with the same tread depth as my fronts, and it made noise and bound up rolling straight, come to find out they were almost an inch shorter.
thats not my case now, but the way you described is exactly how it acts with mis matched tires.
Even though they are the same numbers, they can still be too far off to roll the same. very critical to have all 4 matching.
There is a TSB somehwere about the T case noises and problems being caused by tire size.
I think your pinion slop must be in the spider gears and axles, 2" of backlash would never happen, there would be no teeth left by that point, its hard to feel .005" of backlash when theres oil in there.
ON my T case i ripped it apart and found a bad bearing on the 4wd clutch housing, #8 on this diagram http://www.rsgear.com/NV_246.htm and #24 bearing was worn out, although i couldnt move the yoke around at all. Aslo remember thats the NV246 auto T case, the manual shift T case is different.
but i have a ton of highway miles in 4x4 on this truck, and i still roll along 65mph in the snow if the road is empty, and it gets abused pretty bad sometimes, donuts in the snow, wheel hopping through deep crap, im not very nice to the drivetrain, it happens.
In the past i had bridgestone dueler AT, i put 2 half worn out dueler AT revo's on with the same tread depth as my fronts, and it made noise and bound up rolling straight, come to find out they were almost an inch shorter.
thats not my case now, but the way you described is exactly how it acts with mis matched tires.
Even though they are the same numbers, they can still be too far off to roll the same. very critical to have all 4 matching.
There is a TSB somehwere about the T case noises and problems being caused by tire size.
I think your pinion slop must be in the spider gears and axles, 2" of backlash would never happen, there would be no teeth left by that point, its hard to feel .005" of backlash when theres oil in there.
ON my T case i ripped it apart and found a bad bearing on the 4wd clutch housing, #8 on this diagram http://www.rsgear.com/NV_246.htm and #24 bearing was worn out, although i couldnt move the yoke around at all. Aslo remember thats the NV246 auto T case, the manual shift T case is different.
but i have a ton of highway miles in 4x4 on this truck, and i still roll along 65mph in the snow if the road is empty, and it gets abused pretty bad sometimes, donuts in the snow, wheel hopping through deep crap, im not very nice to the drivetrain, it happens.
Last edited by racerx55; February 12th, 2010 at 9:24 PM.