No 4wd Afwd, help - suggestions?

[cooleydub]

I have a 2002 Trailblazer 4.2 I6. The 4WD and A4WD are both not engaging. Brought to a mechanic who is my wife's cousin and he said the problem is likely with the front differential and recommended another shop with lower hourly labor costs. He told me the motor that engages the 4WD is working fine. The front axle does engage but both cv shafts do nothing. Also there was a clicking sound from the front passenger side wheel when he spun it on the lift. He also pointed out that the front differential was hot to the touch which scares me . It makes no strange noises while driving and still gets the same MPG as it always has. How dangerous is it to drive this way and does it sound like the differential will need replacement? I thank you for reading and welcome any help or suggestions.

[freddyboy61]

Sounds like the front spline disconnect assembly has gone south. This assembly tends to dry out and then wears the bearing. It's probably not a good idea to keep on driving without at least getting a real diagnosis, since some of these parts still run even when not in 4WD mode.
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[NoId]

When my front differential went the truck locked up in awd and 4wd ,but would drive fine in 2wd however it still made a noise from the front differential located near the front right of the truck. Without having the money to fix it at the time I removed the front drive shaft and kept the truck in 2wd. The front differential will still move because the cv axles are still connected ,but the noise mine was making in 2wd disappeared once the front drive shaft was out.

[ellis1905]

I have a 2005 Trailblazer and both the ABS, Brake, & 4-wheel drive
service lights came on all at the same time. Had the transfer case serviced and cleaned the speed sensors and no change. Ant ideas???