FJ 40 tranny swap

4.0 fury

Well-Known Member
Joined
Jun 28, 2005
Location
Callaway, VA
1973 FJ40 with no transmission and tcase installed...

two options

1. rebuild the 3 speed trans/tcase

2. install a working later model 4 speed trans/tcase

the truck has a 4" suspension lift and 35" AT tires
which of these setups would be better suited for a primarly daily drive that would see little to know mild wheeling

recomendations on the best setup and what would be needed for the 4 speed swap in terms adapter plates and would the driveshafts need to be modified (dont know if the cases are the same length or will bolt up to the different trans/case input/outputs
 
Put the 4-speed in it. Don't waste any time or money on rebuilding a 3-speed. First gear is not synchronized in the 3-speed. Save the t-case from the 3-speed, it has a lower low range. You can adapt it to fit in the future.

To put the 4-speed into a '73 FJ40 you'll need the bellhousing that came with the 4-speed, it will bolt directly to the '73 engine. You'll also need the driveshafts that came with the 4-speed. You may have to swap the yokes at the differential end of the driveshafts so they'll bolt to the diff flange.

It's a pretty easy and common swap.
 
RKBJR is right on the money about the tcase/tranny combos. As an old FJ40 owner '(67 and '71) with the original engines and Chevy conversions later x 2, and both bought new, BTW, I can tell you from personal experience that the daily drivability factor with the 4 speed is about 10 to 1 over the three speed. The 4 speed actually gives you useful gears for the various 25/35/45 mph speed limits and hills in the Boone area, and anywhere else for that matter. It's jus' mo' bettuh.
 
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