Just wondering.... I have an '01 Expy w/ AWD. I may need to drive it for a couple weeks without the front driveshaft in. Anybody know if that'll cause havoc with the AWD?

I don't think there's any speed sensors on the front output of the t-case, and I'm thinking of keeping it in 4-Hi so the clutch isn't engaging on a stopped front output if I slip the tires a little. Any ideas?

--Dan

 

There is a sensor for the front driveshaft. In AWD the GEM measures the speed of both the front and rear driveshaft. When it sees a large difference it adjusts the duty cycle on the clutch and that engages the front driveshaft. With no front drive shaft to turn the sensor it will engage the clutch and still see no change and set a code. Leaving the switch in 4hi should keep the GEM from setting codes.

JMC

 

Hmm, where is this sensor? I don't see how a code would be thrown. The sensor can't be on the driveshaft itself. If it's in the diff or in the knuckles, it'll always read correctly as there is no axle disconnect.

If it's on the front output, when the clutch engages, the front output will turn and the sensor would read correctly. It does seem the clutch would constantly engage/disengage though which probably wouldn't be very good for it.

Anyways, 4-Hi should avoid any issues that might happen? I'll just do that. I'll only be for a short time.

thanks
--Dan

 

The sensor is in the transfer case. The front drive shaft always turns the front output shaft. The sensor sends this info to the GEM which in turn compares it to the rear out put shaft sensor speed. When the difference reaches a predetermined difference, like when the rear wheels spin, the GEM cycles the clutch and that sends power to the front drive output shaft. In 4Hi the transfer case is locked so both the front and rear output shafts are turning at the same speed. There is no difference to sense.

JMC