'96 B3500 5.2l drive shaft/transmission noise
#1
05-22-2008, 10:37 PM
'96 B3500 5.2l drive shaft/transmission noise
I don't have much detail because this just started happening and only twice. I'm concerned enough that I thought I'd post here for ideas on where to look further.
I do a lot of off-highway driving on dirt roads in the mountains. The other day I was climbing a very steep grade and pulled over to let a car pass. I didn't stop completely, but almost. As soon as I hit the gas again, there was a rather loud "clacking" noise from under the van. It struck me as similar to the noise you might get if you accidentally put your car in park before it has fully stopped -- kind of a playing card in the spokes sound. I immediately put the van in neutral and coasted backward to the pullout. I thought maybe I'd just picked up some brush, but I found nothing. So I put it in drive again and the same thing happened. I decided to see what would happen if I kept going, and sure enough the noise stopped as soon as it shifted into the next gear.
The exact noise did not re-occur, but today I was backing up on a moderately steep dirt road to turn around, and heard something similar, in reverse. The noise was not nearly as loud and was lower in tone and not as sharp. It persisted maybe the 100 yards I was backing up, but immediately stopped when I put it in drive and moved forward.
I have checked the transmission fluid regularly and the level is normal and stable. I suppose it's possible that this is related to work I've done recently -- I replaced the passenger side front brake rotor and repacked the bearing... but it seemed to me the noise was further back and more in the middle, not exclusively on the passenger side.
These are the only two times I've heard this, and both have been at quite low speed. So I was wondering if it was something to do with the torque converter, transmission, or drive shaft.
If you have any suggestions about where to look further, they would be very much appreciated!
I do a lot of off-highway driving on dirt roads in the mountains. The other day I was climbing a very steep grade and pulled over to let a car pass. I didn't stop completely, but almost. As soon as I hit the gas again, there was a rather loud "clacking" noise from under the van. It struck me as similar to the noise you might get if you accidentally put your car in park before it has fully stopped -- kind of a playing card in the spokes sound. I immediately put the van in neutral and coasted backward to the pullout. I thought maybe I'd just picked up some brush, but I found nothing. So I put it in drive again and the same thing happened. I decided to see what would happen if I kept going, and sure enough the noise stopped as soon as it shifted into the next gear.
The exact noise did not re-occur, but today I was backing up on a moderately steep dirt road to turn around, and heard something similar, in reverse. The noise was not nearly as loud and was lower in tone and not as sharp. It persisted maybe the 100 yards I was backing up, but immediately stopped when I put it in drive and moved forward.
I have checked the transmission fluid regularly and the level is normal and stable. I suppose it's possible that this is related to work I've done recently -- I replaced the passenger side front brake rotor and repacked the bearing... but it seemed to me the noise was further back and more in the middle, not exclusively on the passenger side.
These are the only two times I've heard this, and both have been at quite low speed. So I was wondering if it was something to do with the torque converter, transmission, or drive shaft.
If you have any suggestions about where to look further, they would be very much appreciated!
#2
05-22-2008, 11:58 PM
RE: '96 B3500 5.2l drive shaft/transmission noise
This is only a guess.
If the noise is only at slow speeds, whilemanouvering, perhaps the spider gears in your axle are not meshing properly and binding when the outside wheel has to turn faster than the inside wheel.
If you have a limited slip orsure trac or posi rear, maybe that unit (which replaces the spider gears) is toast.
If the noise is only at slow speeds, whilemanouvering, perhaps the spider gears in your axle are not meshing properly and binding when the outside wheel has to turn faster than the inside wheel.
If you have a limited slip orsure trac or posi rear, maybe that unit (which replaces the spider gears) is toast.
