Hi fellow members I'm new here and hope I do all of this right so here goes. I have an 02 tb and I'm having issues with 4wheel drive . The lights on the selector knob all work like they should when I shift from 2hi to a4wheel I here 2 noises and it works as it should . When I shift to 4hi I here a short noise like its engaging but don't have 4 wheel drive . When I shift to 4lo I here a short noise and a clunk and it appears to work. I took it to a mechanic and he checked it all out didn't find any trouble codes and has no idea what the problem is. I've read about tccm issues and wonder if that's a possibility? Thanks in advance for any help you can give me
02 TB 4x4 problems
- Thread starter Crazyjet1
- Start date
RayVoy
Member
- Nov 20, 2011
- 939
Probably best to eliminate the front axle disconnect (it's easy to test).
Truck in 2wd, jack up the front passenger wheel, turn the wheel by hand the inner half of the axle should not turn.
Turn truck on, leave in PARK, switch to 4wd hi (you can turn off the engine). Turn the passenger wheel, the inner axle shaft should be connected to the outer shaft. The wheel outer and inner axle halves may turn together, or the wheel may not turn. This is normal, and depends upon where the gears are in the diff.
Truck in 2wd, jack up the front passenger wheel, turn the wheel by hand the inner half of the axle should not turn.
Turn truck on, leave in PARK, switch to 4wd hi (you can turn off the engine). Turn the passenger wheel, the inner axle shaft should be connected to the outer shaft. The wheel outer and inner axle halves may turn together, or the wheel may not turn. This is normal, and depends upon where the gears are in the diff.
Welcome! Glad you found us!
When you say it "works as it should" in A4WD and 4LO modes, do you mean you have actual front wheel activity and torque? Or driveline binding if you're on dry pavement and try to turn? In A4WD mode, you should not get much torque transfer to the front wheels unless the rear has broken loose and started slipping.
If it's just that you hear the actuator noises, a functional test is necessary.
How many miles do you have, and has the transfer case fluid been changed every 50K as required? It's vitally important that the fluid get checked and changed that often, which many owners, especially of second-hand trucks, don't realize. What's the maintenance history on it?
When you say it "works as it should" in A4WD and 4LO modes, do you mean you have actual front wheel activity and torque? Or driveline binding if you're on dry pavement and try to turn? In A4WD mode, you should not get much torque transfer to the front wheels unless the rear has broken loose and started slipping.
If it's just that you hear the actuator noises, a functional test is necessary.
How many miles do you have, and has the transfer case fluid been changed every 50K as required? It's vitally important that the fluid get checked and changed that often, which many owners, especially of second-hand trucks, don't realize. What's the maintenance history on it?
Thank you for the responses so far.
Ok to help I have a new issue . I started the tb this morning and the 2hi light started blinking then went out completely so I tried switching through all the different options and found the same on all of them the light would come on blinking then go out completely. The truck has 127000 miles on it and I bought it with 115000 they said the proper maintenance had been done but if your like me I never believe that. Lol the mechanic I took the truck to said A4wheel was working and so was 4lo . I tested A4wheel on a snow covered road and when the rear tires broke loose I could feel the front tires kick in. I tried 4lo and wasn't able to tell if there was actual drive going to the front wheels just that it was in low range. I hope this helps and thank you
Ok to help I have a new issue . I started the tb this morning and the 2hi light started blinking then went out completely so I tried switching through all the different options and found the same on all of them the light would come on blinking then go out completely. The truck has 127000 miles on it and I bought it with 115000 they said the proper maintenance had been done but if your like me I never believe that. Lol the mechanic I took the truck to said A4wheel was working and so was 4lo . I tested A4wheel on a snow covered road and when the rear tires broke loose I could feel the front tires kick in. I tried 4lo and wasn't able to tell if there was actual drive going to the front wheels just that it was in low range. I hope this helps and thank you
Please fill out your profile so we can get reminded more easily that you have a 2002.
If the light(s) on the mode selector switch go dark, does the gauge cluster light up the "service 4WD" lamp? If it does, you have one of the high failure rate 2002 TCCMs. And nothing else matters much until you have a trustworthy 2003+ TCCM installed.
If the light(s) on the mode selector switch go dark, does the gauge cluster light up the "service 4WD" lamp? If it does, you have one of the high failure rate 2002 TCCMs. And nothing else matters much until you have a trustworthy 2003+ TCCM installed.
Thank you . I found an 03 in a junk yard for $75 will the tccm still have to be reprogrammed once I install it?
If the TCCM came out of a working 4WD truck (not the AWD variants like a Bravada), then it will be plug and play. AWD variants and new, virgin TCCMs bought from GM vendors will need you to pay the dealer's tribute (sometimes $100 for ten minutes work).
Ok I got a used tccm install and the switch light issues seem to be fixed but still don't have 4Hi or 4Lo. A4wheel works great. Any ideas on what to check now?
Crazyjet1 said:
Scratch that, I got back in a little while later and still having an issue with the light on the 4wheel switch blinking for 10 or 15 seconds then goes out.
