M813 no 6x6 slipping help

[zxmedic]

So I've read all the tm and not much I can find about this problem under no load front drive shaft spins drives the front wheels .Today I wanted to make sure the front axle was engaging this is what is noted as you load up the drive line the front drive shaft starts to turn moves about a half an inch then slips back wheels are spinning in the back when I shift you can hear the air for the sprag as I believe it should I've tried it in high range and low range back off and start moving again the front drive line starts to load up moves about half an inch then slips the wheel does the same . Any ideas. There are no obnoxious noises .no grinding nothing

 

[swbradley1]

You could drain the transfer case, fill it with diesel and drive it 50 miles, drain the diesel, fill with the proper oil and try it again.

The front wheels only have power when the rear wheels slip, not when you are driving. That's the Sprag.

 

[zxmedic]

I parked the truck against a tree started to spin the rear wheels back off then started again the drive shaft and left front tire starts to spin but only rotates about an inch then stops even though the rears are still spinning .. oil is new .. you think sprag slipping ?

 

[swbradley1]

Sounds like it might be. But unless you break something it's that Sprag most of the time. The diesel "cleans" them.

 

[zxmedic]

Will give it a try thanks