my shaft is spinning!

[cwillie872003]

ok... i just got my first explorer. and its my first 4 wheel drive vehicle. its a 96 xlt with the control track <-- what ever that is... i had it on a lift today trying to figure out what the thumping noise was and that turned out to be a u joint. but anyway should the front drive shaft be spinning when the truck is out of 4 wheel drive??? like i said this is my first 4 wheel drive so i really dont know much about them... thanks

chris

 

[Aussie Explorer]

With control Trac, Yes, The front is always engaged as the Hub’s are permanently locked.

The control Trac system works by shifting power to the front when slip is detected at the rear.


AUTO> Automatic 4WD, the system sends power to the front axle as it need’s it
HI> 4WD front and rear drive shafts are locked together, do not use this on hard surfaces or you will brake stuff
Low> Same as high but with a 2.48:1 drive reduction, For use in tuff off road conditions, Soft sand, Mud, Rock hopping ECT.

 

[JoshC]

Aussi is right, but he forgot to add that the 95 and up Explorers are independant front suspensions and have CV (constant velocity) shaft, which means they don't unlock, so they spin all the time.

 

[cwillie872003]

ok thanks that helps... but why is the front drive shaft spinning but none of the front wheels spinning? keep in mind i had it on a lift and all 4's were off the ground

 

[inh]

most likely because you have a vacuum disconnect on your passengerside axel, and an open differential. so while the front shaft may be spinning, all the power will be transfered to the passenger axel which is disconnected from the wheel, so that part of the differential will spin. nothing to worry about

 

[cwillie872003]

well that takes a big load off my sholders... i though something was very screwed up... not to stray off topic or anyting, but how hard is the front drive shaft u-joint to change? its the one that comes out of the t-case

 

[gijoecam]

Indeed, the front driveshaft tends to still turn due to the design of the clutch in the transfer case. There will be some friction there even in 2wd, so although the front shaft may *turn*, it's not transmitting (or draining) any power.

As for the u-joint, it's pretty much just like any other u-joint. Not a big deal.

-Joe