diggerdpilot

Hi all,
Kinda new to this forum, but hang around others.
My wife's ride is a 2002 Tahoe, which she loves, but it has a squealing noise now from the front of the transfer case, at low speed, mostly under 10-12 MPH. At higher speeds, it goes away. It almost sounds like a bearing letting go, but my questions are....
Does the TC have to come off to replace, or can you get it by dropping the front shaft?
Has anyone had this happen?
Could it be the front seal? It is coming from the front where the shaft attaches to the case, on the case itself. I can duplicate the noise with the truck up in the air and in N, and the transfer case itself works fine, 4H, 4L, N, and 2WD all work great.

The oil level seemed OK, but I dont have a lot of experience in cases this new.

Thanks for the help in advance,

ZX1100F1

Transfer case needs to be removed and split apart to replace bearings, I would also agree with you that it does sound like a failed bearing.
Bad seals will leak but not squeal.

You may want to consider just R&R'ing it with a rebuild unit, they require some special tools and know-how to get apart and back together; just like an automatic transmission does.

You didn't purchase an extended service agreement by any chance did you? If so, they normally cover these repairs.

diggerdpilot

Naw, she bought it with 25K on it, and it is up to like 78 or 79K now.
How bad is it to replace? Drop the wiring, shafts, and the unit? Then reverse? Anything prone to jumping out of the woods at me?
Thanks, appreciate it.
Digger

ZX1100F1

Nope, it is straight forward but I always recommend a shop manual, Chilton's at the very least.
Below I have pasted vague instructions with out pictures:

Document ID# 752416
2002 Chevrolet Tahoe - 4WD [hr] Transfer Case Assembly Replacement Removal Procedure [ol]


Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information. Remove the transfer case shields. Refer to Transfer Case Shield Replacement . Remove the front propeller shaft. Refer to Propeller Shaft Replacement - Front in Propeller Shaft. Remove the rear propeller shaft. Refer to Propeller Shaft Replacement - Rear in Propeller Shaft.


Disconnect the motor/encoder electrical connector.


Remove the transfer case vent hose.


Remove the electrical wiring harness from the transfer case. Important:Ensure that the transfer case is correctly secured to the transmission jack.
Support the transfer case with a suitable transmission jack.


Important:When removing the transfer case from the transmission, do not remove the transmission mount or the transfer case adapter.
Remove the transfer case retaining nuts from the transfer case studs.


Separate the transfer case from the transmission by moving the transfer case straight back toward the rear of the vehicle. Rotate the transfer case so that the transfer case is perpendicular to the transmission assembly. Lower the transfer case. [/ol] Installation Procedure [ol]


Rotate the transfer case so that the transfer case is perpendicular to the transmission assembly. Raise the transfer case into position. Rotate the transfer case so that the transfer case aligns with the transfer case adapter. Install the transfer case assembly.


Notice:Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems. Install the transfer case retaining nuts.
Tighten
Tighten the transfer case retaining nuts to 50N·m (37lbft).


Install the transfer case vent hose.


Install the electrical wiring harness to the transfer case.


Connect the motor/encoder electrical connector. Install the front propeller shaft. Refer to Propeller Shaft Replacement - Front in Propeller Shaft. Install the rear propeller shaft. Refer to Propeller Shaft Replacement - Rear in Propeller Shaft. Inspect the transfer case fluid level. Refer to Transfer Case Fluid Replacement .


Install the transfer case shield. Refer to Transfer Case Shield Replacement . Lower the vehicle. Refer to Lifting and Jacking the Vehicle in General Information. [/ol] [hr] Document ID# 752416
2002 Chevrolet Tahoe - 4WD

diggerdpilot

Cool, thanks for the info. I think I am going to end up flopping a new one in it. One more question, the oil in it, whatever fluid they use, is black, is that the normal color, and is there any chance a low fluid level would dry the bearing enough to make it squeal?
I probably know the answer, but am looking for anything to keep from doing this.

ZX1100F1

Your Tahoe uses Auto-Trak-II (P/N 12378508) fluid which should be a light blue color.

The T/C capacity is 2 quarts and if the level gets low it can cause overheating and damage to just about all the components in the case.


Before you replace the unit I would suggest draining and refilling with fresh fluid to the proper level and see if that helps.