Sprag Transfer Case

[KsM715]

I dont know if they have anything like the REB kit that removes and replaces the sprag. But on the 809 5tons you can put a valve in the airline to the transmission and basically "shut off" the sprag. By shutting off the air it lets the sprag clutch remain in neutral.

 

[nmwildman013]

OK, we did the install of lockouts on a sprag transfer case deuce and it works just fine. It solved a lot of the binding/ popping issues and the truck drives much, much better. The forward sprags were worn out and when we fixed that we encountered a lot of the same problems you had. All that went away with the lockouts. Liked them so much we bought another set and installed them on another deuce we drive. Only downside is the cost.

 

[unix84535]

1968 Deuce with Sprag transfer case. Had to take the front drive shaft out due to issues. Was thinking maybe it was an adjustment issue, but given what I am about to describe was hoping someone with intimate familiarity could provide some input. While driving occassionally Deuce would start wobbling in front end, then after a sharp turn wobbling would go away. One time it felt like the right front tire was flat (due to wobbling), then made left turn and everything was fine. Sometimes while driving would pull sharply to one side. Short time later after driving for a while, went to pull into a parking garage, wobbling, made left turn and heard very loud boom, like a detonation and then everything was fine. Removed front drive shaft and have never had another issue. Problems are definitely with sprag transfer case. Could be an adjustment issue, as most issues developed if truck drifted backwards a few inches/feet prior to pulling forward. My question is this: given the loud detonation sound at last incident, what would cause that? Is the system still salvageable with adjustment or should I look for metal shavings in the case from broken parts if I drain the transfer case? Right now everything runs/works fine without the front drive shaft, I'm just looking for input to get it back to proper stock/original operating condition. Yes, I know about how changing over to air transfer is better, I'm looking for input on the sprag system in particular. Thanks in advance.

My 1970 M818 5 Ton 6x6 Has a Sprag Air Cylinder that controls the engaging and disengaging of the front Axle. Presently my Airc ylinder failed and caused the Front axle to stay engaged. Causing extreme loads while on the Tarmac. Your Problem may be that the front axle is engaged when it should not be engaged. That being said. The First thing I would do is Jack up the front axle and Check for Play in the front wheels, Inspect steering linkage for play; you may have a more than one problem. After inspecting the front axle for play or damaged parts I would check to see if the front drive of the Transfer case is engaged while truck is aired up and running, if it is then you may have a damaged air cylinder. The next thing that I would do is remove the Sprag Air cylinder and inspected it to make sure it is not damaged. Good Luck. Seems that https://www.eriksmilitarysurplus.com/airshcyforsp.html Has the best price on Air Cylinder replacement.

 

[unix84535]

Do they have anything like the REB kit for the 5 ton transfer case?

I have had a problem with my Transfer case engaging the front axle when not in gear. I found the Air cylinder sprag seals leaking and spring retainer cracked. I am designing an air actuator to control when I am in 6x6 wheel drive and when I am in 4 Wheel Drive. Just started the process Yesterday will keep you updated. When I finish the project. If you are interested Let me know.

 

[gringeltaube]

After inspecting the front axle for play or damaged parts I would check to see if the front drive of the Transfer case is engaged while truck is aired up and running, if it is then you may have a damaged air cylinder. The next thing that I would do is remove the Sprag Air cylinder and inspected it to make sure it is not damaged.

Please keep in mind that we are talking about the Deuce's sprag T-cases (model T-136-21). These don't have an air cylinder; both sprag clutches are shifted mechanically, 100%.