Changing to a th400 from a 700r4, what needs to be done?

[rocko]

I'm picking up a TH400/205 combo... what needs to be done in order to get it to work, The truck has a 700/241 in it now. I know the 700 had the TV cable.. what does the 400 have that i'll need to install?

And the 205 i'm buying is a slip-yoke 205, how hard is it to convert to a fixed yoke?

 

[4x4k20]

you will need to do away with the tv cable and run a vacum line. also you will need a kickdown switch for a turbo 400 it mounts down at the gas pedal it has one wire the runs down to the transmision best thing to do is find one in a junk yard off a turbo 400 truck . also you may have to do a little driveshaft work because the 400 is about 2 inches shorter than the 700r4. and on the rear 205 i think ord sells the swap kit for this .

 

[84_Chevy_K10]

You'll have to do quite a bit of driveshaft work if you swap to a fixed-yoke 205. Obviously your 700R4 has a 208 or 241 behind it and those are both slip yoke transfer cases. The new fixed yoke design will require an entirely different type of rear driveshaft. /forums/images/graemlins/smile.gif

Other than that, like said above, vacuum modulator line is necessary, and kickdown switch if you want it to kick down when you kick it in the ass.

 

[90K5]

why would that require a totally different type of driveshaft? the yokes on the shaft are the same on each driveshaft, just different on the t-case. might need lengthened or shortened depending on how the length of the 205 affects it

 

[84_Chevy_K10]

A fixed yoke transfer case will require a slip spline within the shaft. That will basically require a whole new shaft, unless you simply use the tube and one end, and weld the slip spline on the front. Since that's about $175 for just that one part, I think you'd be better off finding a driveshaft and having it shortened and balanced so it'll work with your rig.

 

[rocko]

Thanks everyone... this is a good starting point for doing my conversion.