Unusual noise.
Moderator: F9K9
Unusual noise.
I started to hear slight grinding metalic noise with a little bit of resistance on the drive train. Getting louder everyday at speeds around 50 mph I checked the front wheel bearing (seem ok) then I checked to if it the front wheels are engaged in 4x4 when selector says 2 wheel drive (seams ok) I am thinking its the transfer case, it feels like it is always engaged and starting to come apart driving it at highway speeds. Is this possible since the fronts are not spinning in 4 wheel drive? How could I unlock the tranfer case to test this theory? Is this from the faulty vacuum switch everyone is talking about or something else. This is my best guess right not. Other than the front or rear end bearing going out.
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crew cab sonoma
- Crew Elite
- Posts: 238
- Joined: Wed Aug 25, 2004 2:21 am
- Location: Chattanooga, TN
did you check to see if the front diff. was engaged with the engine off, or running? if the engine isnt running, and the transfer case is stuck in 4WD, the vacuum reserve may be bleeding off, causing the front diff. to unlock.
check it with the engine idling, just to be sure...
but i would think that there would be some kind of malfunction indication on the pushbutton control switch. unless there are some failures that dont show up?
check it with the engine idling, just to be sure...
but i would think that there would be some kind of malfunction indication on the pushbutton control switch. unless there are some failures that dont show up?
[size=75]Lee
01 Sonoma Crew Cab 2.21 60ft. 10.24 @ 66.5 mph (1/8mi.)(SOLD)
00 Sonoma Ext. Cab 4WD. front axle removed, Torsen diff. W4M pcm. 2.10 60ft. 9.64 @ 71.0 mph (1/8 mi.)[/size]
01 Sonoma Crew Cab 2.21 60ft. 10.24 @ 66.5 mph (1/8mi.)(SOLD)
00 Sonoma Ext. Cab 4WD. front axle removed, Torsen diff. W4M pcm. 2.10 60ft. 9.64 @ 71.0 mph (1/8 mi.)[/size]
First things first, pull the vacume line off the front diff actuator and cap it. If the problem goes away what is happeneing is somehow a slight bit of vacume is getting to the diff and partially engaging the diff.
[size=75][b]1991 GMC Sonoma Extended Cb[/b] - 4.3L Automatic, 2" BL, 31" BFG's.
[b]1992 Chevy T-10 Reg Cab[/b] - 4.3L 5spd, 3" Bl, 31" Mud Tires. Hooker long tube headers and true duals.
[b]1999 Oldsmobile Bravada[/b] - Wifes truck, all stock.[/size]
[b]1992 Chevy T-10 Reg Cab[/b] - 4.3L 5spd, 3" Bl, 31" Mud Tires. Hooker long tube headers and true duals.
[b]1999 Oldsmobile Bravada[/b] - Wifes truck, all stock.[/size]
With the truck sitting still and the engine running, try to turn the front driveshaft. If it turns easily then your transfer case and your front axle are disenguaged.
From what you have described I would bet on one of the front hubs. Jack up the front and remove the front brake calipers. Rotate the hub slowly by hand and see if you feel any roughness. Very little roughness in the hub assembly will make a low rumbling noise at 50 mph.
If your driveshaft doesn't turn then post back.
James
From what you have described I would bet on one of the front hubs. Jack up the front and remove the front brake calipers. Rotate the hub slowly by hand and see if you feel any roughness. Very little roughness in the hub assembly will make a low rumbling noise at 50 mph.
If your driveshaft doesn't turn then post back.
James