Automatic-to-Manual Transmission?

[Bombadier]

found a '76 J-10 w/ 258 6cyl and a manual 3-spd (?) transmission.....my '77 is an automatic, and i'd LOVE to make the switch.....any serious complications to look out for?
so, from a TH400/B-Warner QT x-fer case, to a T-15A tranny and i'm guessing a Spicer 20 x-fer case, anything else i'll need?

[Chero77]

I think the transmission swap would be straight forward. A couple of people on the board have done this and reported that its just a matter of transferring parts, albiet, its a lot of work.

The problem (if its a problem) will be with the rear axle. The rear axles I have seen for Dana 20 equipped vehicles have the rear diff slightly offset from center (to allow the driveshaft to clear the gas tank). QTs however, have more than twice the offset. Some people have reported "bad vibes" (literally) when running the Dana 20 with the offset QT axle. Others have said its not a problem.

The best solution would appear to be to swap in the centered rear axle from the J-truck. However, I looked at a J-truck rear axle in a junkyard and the shock mounts and spring perches did not appear to be in exactly the same place as the ones on a Widetrack Chero. I was just eyeballing the locations so I may be wrong or they may have changed slightly from year to year. Don't know if it makes any difference if they are off a 1/2 inch, but I'd find out. Guess I would get out a tape measure and see if the rear axle on your J-truck is a bolt-on for the Chero. Also since the J-truck has a six, the gears are probably different and you would have to swap in the 3.54s from your Chero.

Another option is to use a Dana 18 in place of the Dana 20. This would elimanate the hassle of swapping axles at the expense of more gear noise and probably a loss of some strength. I think if the J-truck rear axle is directly swapable I would go that route. Otherwise, I'd go the Dana 18 route.

If you go ahead with this project let us know how it works out. Especially, let us know if the J-truck rear axle will bolt in.

[effle18]

This is funny because I have a J10 with a 3 speed and would like to put in an auto trans. If its doable maybe we could work out a swap if you don't have any plans for your tranny.

[joe]

I don't know about the 3 speeds but the 4 speeds(T-18, T-18A's) that come behind the 258 have a shorter input shaft than the 4 speeds behind 360's due to the placement difference between the motors. I'd suspect the same goes for the 3 speeds but not sure?

[Jerk]

rear axle diff housing offset, tranny linkage and shifter location, (not to mention clutch pedal mounting and linkage) and I'm sure other little irritations will be some of your hurdles...I think driveshaft length and crossmember location etc will have to be addressed as well. NOTE: I have never attempted the swap (and don't wish to, but these are just some differences in the setups between stick and auto jeeps. Alot more involved than just bolting in a different tranny, hunh?

[nightflyers]

I have a t-18 sitting in the garage that I was planning to swap in. I decided not to because of the amount of work and money involved.

Is your 77 also a 6cyl? If not, the flywheel and cluch will need replaced with one from an 8cyl. Not sure about the input shaft length. If you swap the rear out, you will have clearence issues with the gas tank.

[OBX-AUTOMOTIVE]

I CAN'T HELP YOU WITH YOUR SWAP..... ..BUT WHEN I WAS YOUNG..TEEN YEARS,THAT WAS A WAY OF LIFE....YOU WOULD SWAP,ENGINES AND TRANS IN ALL KINDS OF CARS-TRUCKS...BUICK POWERED 57 FORD!!...OLDS POWERED 50s FORD PUs ...I HAD A HEMI IN A 54 MERC.... ALL KINDS OF CRAZY STUFF....SO THE POINT THAT I'M MAKING IS,YOU CAN DO ALMOST ANY KIND OF SWAP...IF YOU WANT TO!!....GOOD LUCK :cool: :cool: