Linkage for 4-speed trans + 3-speed case

Joined
Feb 9, 2002
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After a year or two of ignoring my 40, I'm finally buttoning up my 4-speed trans swap and just realized my 3-speed t-case linkage doesn't work. It looks like the front-drive shift lever (11) ends up in the wrong place, and the high-low shift rod (6) is the wrong shape.

Do I need all 4-speed linkages to get this working? Or is there some clever solution I haven't been able to find online?
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Joined
Apr 4, 2006
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I went the other way, '78 4 speed (h41) and swapped in a 3-speed case. I don't remember having to change any part of the linkage, so yea, you probably want 4-speed parts. While you're in there you might want to add t-case savers. I got mine from Valley Hybrids.
 
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On number 16 box the shaft #17 is too short on a three speed to use with a four speed. There are a number of pieces in the linkage that are different between three and four speeds. Would change #45 and #64 on the top of the transfer case along with the number 16 box. Then run the simpler 4/75-7/80 linkage. Or find a complete transfer four speed linkage up to 4/75. Fewer parts to vibrate after 4/75. A PO of my 79 used a mix of parts when the transfer case was replaced with one our of a 74 four.
 
Joined
Feb 9, 2002
Messages
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On number 16 box the shaft #17 is too short on a three speed to use with a four speed. There are a number of pieces in the linkage that are different between three and four speeds. Would change #45 and #64 on the top of the transfer case along with the number 16 box. Then run the simpler 4/75-7/80 linkage. Or find a complete transfer four speed linkage up to 4/75. Fewer parts to vibrate after 4/75. A PO of my 79 used a mix of parts when the transfer case was replaced with one our of a 74 four.
Thank you, I'll see if I can track down those parts as an assembly.
 
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Did some looking it's the lever thru the floor, piece that bolts to it and thebshidt gate that are different. Those and the box that bolts to the transfer case and should be good.
 
Joined
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Did some looking it's the lever thru the floor, piece that bolts to it and thebshidt gate that are different. Those and the box that bolts to the transfer case and should be good.
Very cool, thank you.
I'm thinking of just whipping up something on the lathe to extend the shift shaft. I figure a piece of round stock bored to fit over the shaft with a set-screw to grab the flat would work, then have a flat at the other end where my shifter would engage. A replacement for the high-low shift rod (6) should be easy enough to bend up if needed, which means I might only need the shift-gate (and possibly the shifter lever). I intend to go wheeling in a couple weeks so whatever is faster will probably win.
I have all of those parts Dave at rockntag@msn.com. Send me an email not on MUD too much anymore..Thanks
Sent.
 

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