700r4 th400 swap ?

[jp0863]

what is involved in swapping a th400 into a suburban with a 700r4? i'm looking at buying a suburban, but not having a whole lot of luck finding a 3/4 ton that i like. there are tons of 1/2 ton suburbans out there and all the ones i'm looking at have the 700r4. i would prefer a th400 since i dont want overdrive and dont want an electronic controlled tranny.

 

[4X4HIGH]

You would need a TH400, adapter, and the t-case to go with it unless you decided to swap in the correct input shaft in the t-case.

I'm not too sure about the crossmember but you might be able to re-use the existing one. The TH400 and the 700R4 are close enough in length that if you use the t-case from the 700R4 with the correct input swapped in the driveshafts may even work.

Just for your info, the 700R4 is not electrically operated. The 4l60E which is basically the 3rd generation 700 is however electric.

 

[toomany]

You would also need the kickdown switch and a way to mount it onto the carb/throttle body. Th400's don't use a cable for line presure/kickdown. Also would need a vacuum source for the modulator. The 700's cooler lines would probably be able to be reused.

 

[4X4HIGH]

TH400's aren't like a 700R4 in the fact that you don't "NEED" the kickdown switch. The 700R4 it's called a TV (throttle valve) cable which changes fluid pressure within the trans depending on throttle position. The switch on a TH400 is for nothing more than a passing gear and is not required for the trans to work properly and has no ill effects if it is not working or hooked up.

 

[jp0863]

well i may just wait til i find a 3/4 ton, but figured i would ask ahead of time. my goal is to buy an m1008 and swap the axles and tranny/t-case after rebuilding them of course, so i would have all the parts to swap over (except for the torque convertor- but those are easy to come by)

 

[throttleissues]

Keep in mind that, despite what some people will try to tell you, the 3/4 ton subs have a thicker frame than the 1/2 tons. That's more important to some than others, but I wanted to make sure you knew.

 

[jp0863]

Keep in mind that, despite what some people will try to tell you, the 3/4 ton subs have a thicker frame than the 1/2 tons. That's more important to some than others, but I wanted to make sure you knew.

I was not aware of that, thanks for the info.