th 400 rebuild ?

[pitjeeps]

going to have my th400 rebuilt. anything i should have done to it to make it better off road such as shift kit etc.? i,m going to run a twin stick 300 behind it.both axels are locked.also will it hurt the tranny if i dont hook up the kickdown switch?i could just manualy shift to 2nd gear for passing.i dont think the switch needs to be hooked up for tranny to shift when comming to a stop then take off again.

[Brad W.]

why not hook it up? it's the most simple switch in the world. one terminal gets ignition hot power, the other goes to the tranny plug. Trust me, it's annoying as hell to drive without it.

[pitjeeps]

good point , but will it hurt the tranny if i dont???

[jsinajeep]

I have not had mine hooked up for almost 4yr. now. The transmission guy that I talked too told me I didn't need it to run the way I do. I took the unit out from inside the tranny pluged the wire hole. I still have the kick down sometime when on the road, but most of the time I just downshift. If you are on the road say going up a mountain I downshift an leave it there until I get to the top. I do have the B&M shift kit. Love the way it works.

[J4GRAND]

but will it hurt the tranny if i dont???
No, the TH400 is not like the TF727 where you need the kickdown operational to make the tranny shift properly. If you can live without it, it won't hurt the tranny. Definitely put a shift kit in it. More positive shifting and will make the clutch packs last much longer.

[Bob Barry]

About the only major upgrade you may consider is adding a 32-element sprag and the corresponding front-drum (which you need to change if you have a '70 or newer transmission, as those used a ramp and roller design and thus a different front drum). Sprag is only about $60, and you can find good used front drums from early units, but stronger aftermarket drums are available for about $200-$250, iirc.

[Kimbrough]

Prolly already know this but you have to change out the output shaft to run the 300.