When I try to switch to AWD or 4HI I hear the axle actuator motor working and lights on the switch show that mode has change to desire setting but the front tires are not engaging. I tested it tonight on a snowy uphill driveway. No four wheel drive. Any ideas?
No AWD or 4HI
- Thread starter Jonbussie
- Start date
djthumper
Administrator
When was the last time that you know that it worked? It could possibly be your TCCM. I hope that you have kept up on the transfer fluid changes at 50K intervals.
Being an 02, I'd suspect the TCCM.
Almost certainly a mechanical failure in the front axle disconnect. TCCM failures have different behavior of the mode switch and "service 4wd" lights.
I know it worked last winter. The service 4wd drive light briefly came on when I tried to switch to 4wd. I pulled over, shut the vehicle off. When I turned it back on the service light was off
http://gmtnation.com/forums/topic/106-4wd-not-working-step-inside/Jonbussie said:
http://gmtnation.com/forums/topic/9629-what-to-check-mechanically-on-4-wheel-drive-system/
http://www.offroadtb.com/articles/tech-docs/what-is-wrong-with-my-4wd-system/
http://www.offroadtb.com/articles/tech-docs/front-axle-4wd-disconnect/
For more reading:
http://www.offroadtb.com/articles/tech-docs/transfer-case-tech-the-nvg-226-np8-theory-of-operation/
djthumper
Administrator
You can get either one, there is no preferred one that I know of. It is just being able to get your hands on one.
Play should be under 1/16". Or else the differential seal and bearing could be shot. How many miles since checking it's fluid level?
I've changed the differential seal on the drivers side before but the not differential bearing. Is this a difficult task if the bearing is indeed bad?
I seem to remember some threads here or on ortb about changing it. Sorry I'm not in a position right now to run a search.