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I know I'm opening an old can of worms, here....: A Deuce myth really - which needs to be busted: 
…."With a Sprag T-case one has to start in 1st gear (or shift through first gear) in order to have front axle traction in ALL other FW gears..." Not so...!
Thought it might be useful to post some info I have never seen in the manuals, for better general understanding of the shifting mechanism, showing the different situations and positions of the spring loaded shift rod, to transmit the movement from the tranny shift linkage to the TC shift shaft.
This is how it works:
1) TC shift shaft pulled all OUT => FW (front) sprag engaged => front axle getting traction to pull forward. This is the TC "default" position; same as if all linkage was disconnected.
Pushed IN all the way (about 7/8”) => RW (Rear Sprag) engaged => front axle getting traction, pulling backwards.
2) The internal coil spring is ALWAYS pushing the TC shift rod and fork OUT (to the front of vehicle), hold the clutch collar engaged to the FW-sprag. This happens no matter if the tranny is in NEUTRAL or shifted into ANY of the 5 forward gears.
3) Only when shifting into REVERSE gear (and the sprag clutch-to-collar dogs are offset, allowing full engagement), the shift shaft will be pushed all the way IN (to the rear of vehicle), about 7/8". This is possible since the preloaded coil spring inside the adjustable rod/tube is actually stronger than the action of the TC internal coil spring, so it will overrun it.
In case of the clutch dogs being opposed (aligned) to each other and not permitting engagement (which may happen when shifting while standing still) the spring inside the rod will compress about 7/16”, thus absorbing the positive “excess” travel coming from the tranny shift linkage.
4) Pulling out of REVERSE just into NEUTRAL position makes the shift shaft/fork/clutch return ALL THE WAY (-> 7/8” total travel) to its normal, default position (1) - unless the clutch dogs are again opposed/ aligned (-> only 7/16” partial travel).
5) The same as in 3) applies when shifting the tranny out of NEUTRAL position into any of the FW gears.
IF your Sprag-TC behaves any different, it is either a worn sprag unit, or loose TC mounts, or - most likely - the shift mechanism not correctly adjusted - sometimes all things together…
That shift rod/tube may benefit from a little TLC before attempting final adjustment. Below pics show how it can look like inside…!
Maybe a small oiling hole at its end would be a simple upgrade for better maintenance and performance.
Hope this helps!
Gerhard
…."With a Sprag T-case one has to start in 1st gear (or shift through first gear) in order to have front axle traction in ALL other FW gears..." Not so...!Thought it might be useful to post some info I have never seen in the manuals, for better general understanding of the shifting mechanism, showing the different situations and positions of the spring loaded shift rod, to transmit the movement from the tranny shift linkage to the TC shift shaft.
This is how it works:
1) TC shift shaft pulled all OUT => FW (front) sprag engaged => front axle getting traction to pull forward. This is the TC "default" position; same as if all linkage was disconnected.
Pushed IN all the way (about 7/8”) => RW (Rear Sprag) engaged => front axle getting traction, pulling backwards.
2) The internal coil spring is ALWAYS pushing the TC shift rod and fork OUT (to the front of vehicle), hold the clutch collar engaged to the FW-sprag. This happens no matter if the tranny is in NEUTRAL or shifted into ANY of the 5 forward gears.
3) Only when shifting into REVERSE gear (and the sprag clutch-to-collar dogs are offset, allowing full engagement), the shift shaft will be pushed all the way IN (to the rear of vehicle), about 7/8". This is possible since the preloaded coil spring inside the adjustable rod/tube is actually stronger than the action of the TC internal coil spring, so it will overrun it.
In case of the clutch dogs being opposed (aligned) to each other and not permitting engagement (which may happen when shifting while standing still) the spring inside the rod will compress about 7/16”, thus absorbing the positive “excess” travel coming from the tranny shift linkage.
4) Pulling out of REVERSE just into NEUTRAL position makes the shift shaft/fork/clutch return ALL THE WAY (-> 7/8” total travel) to its normal, default position (1) - unless the clutch dogs are again opposed/ aligned (-> only 7/16” partial travel).
5) The same as in 3) applies when shifting the tranny out of NEUTRAL position into any of the FW gears.
IF your Sprag-TC behaves any different, it is either a worn sprag unit, or loose TC mounts, or - most likely - the shift mechanism not correctly adjusted - sometimes all things together…
That shift rod/tube may benefit from a little TLC before attempting final adjustment. Below pics show how it can look like inside…!
Maybe a small oiling hole at its end would be a simple upgrade for better maintenance and performance.
Hope this helps!
Gerhard
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