transfercase engagement for sprag style Tcase in a 66 deuce.

[seabeehotrodder]

does anyone know the location of the operator manual that shows how to adjust, as well as the proper way to engage the t 136-21 sprag transfer case. it wouldn't work while in 20 inches of snow this weekend. i've been searching for some time now and have already printed out and downloaded several TM's without success. thanks folks.

 

[porkysplace]

TM 9-2520-246-34-1 covers the T-136-21 Transfer Case with the overrunning clutch (often called a sprag). Available in the TM section at Steel Soldiers.

TM9-2520-246-34-1.pdf
TM9-2520-246-34-1 Direct Support and General Support Maintenance manual for Transmission 3053A.

TM9-2520-246-34P.pdf
TM9-2520-246-34P Direct Support and General Support Maintenance Transmissions, Transfers, PTO's.

 

[seabeehotrodder]

porkysplace, thank you very much, am I correct in believing that though the over running clutch is the undesirable TC compared to the 27, it should still be pretty indestructible with mild use. my truck has 12000 miles and spent most of its life in a fire station that rarely used it. its in fantastic condition otherwise.

 

[rustystud]

porkysplace, thank you very much, am I correct in believing that though the over running clutch is the undesirable TC compared to the 27, it should still be pretty indestructible with mild use. my truck has 12000 miles and spent most of its life in a fire station that rarely used it. its in fantastic condition otherwise.

It should give you years of good service. The problem though is that in Snow you might get some binding, or jarring engagements. The over-running sprag doesn't engage until the unit experiences an over running of the rear axles compared to the front driveline. Since wheel spin happens pretty fast in Snow conditions you can get a sharp engagement of the sprag. Unlike in muddy conditions where your driving along and then you start to experience the rear axles start to slowly over spin. Though it can happen pretty fast in mud too. In my experience driving these beasts in the Marines, Snow driving was always a bit more interesting. Though I'm sure plenty here will say they "never" had any trouble driving them in Snow, and they will chime in telling how I'm full of "Shaving cream" ! That's how it usually works here.
I'm just glad I have an "air-shift" transfer-case in mine.

 

[jasonjc]

Also if you let it roll fwd in rev or rev in fwd gear , this can jam up the sprag. There are good thread about that , that can explain it a whole lot better than me. And having a VFD back ground I can tell you that rarely used is not a good thing."But that just my $0.02".

 

[rustystud]

Also if you let it roll fwd in rev or rev in fwd gear , this can jam up the sprag. There are good thread about that , that can explain it a whole lot better than me. And having a VFD back ground I can tell you that rarely used is not a good thing."But that just my $0.02".

Oh don't get me started on the day I had to drive back to base from the desert after jamming that stupid sprag after I lost traction going up a hill and slipped backwards !