Auto Trans Questions

[Jester]

So after having my truck back together and running for a few weeks, I am kinda thinking that an auto trans may have been better. Want to look into some options.

I know the TH400 came in an AMC pattern. Did it ever come in a 2wd version? This would save an adapter. Does the TH400 have any wonky TV cables or such? Would converting to a full manual valve body get rid of them.

What about the 700R4? Overdrive would be nice and deeper first gear. I know they have the wierd TV cable that everyone hates. There are full manual valve bodies for those that get rid of the cable. Some have the opinion that they are bad since they run full line pressure all the time.

Opinions? Real world experience?

Hey Al, what do you think?

[randyscycle]

THe TH400 did come in an AMC pattern, but they are tricky to find and would need a 2WD extension housing and output shaft. The TH400 has no TV cable, only a switch for a kickdown ont he throttle pedal that engages a solenoid in the valve body to downshift into passing gear.

The 700R4 would need an adapter plate.

I have TH400 in mine and I love it. Works excellent and is a stout transmission.

Don't forget you will need to add a trans cooler, lines, and a shifter to the mix as well. A trans temp gauge isn't a bad investment either.

[Roy]

All you need to do is take an AMC main housing...we have 50 or 100 of 'em, get a 2wd output shaft and tailhousing ( the internals and rear housing parts interchange between the AMC pattern version and the GM pattern versions.

[Jester]

The TH400 has no TV cable, only a switch for a kickdown ont he throttle pedal that engages a solenoid in the valve body to downshift into passing gear.

I take it that a full manual valve body would get rid of the need for a kickdown switch?

What about the 700R4? People seem to love or hate them. Know it would need an adapter but the OD is nice. Would it live behind a AMC360 and all the weight of a M715? Once again, I think I would go full manual - engine braking.

[M725baja]

here's my experience from a previous thread- works GREAT!

Allison 1000 tranny

[randyscycle]

You don't really need the kickdown switch at all unless you plan on using passing gear on the highway. I just didn't connect mine and it doesn't matter. All it does is apply 12V to the solenoid to bypass the fluid circuit in the valve body and shift to 2nd gear for passing. Otherwise it works normally.

All of the shift points in the TH400 are controlled by the governor flyweights and springs, which can be changed to change the shift points.

On mine, I used a shift improver kit which is just a reprogramming kit for the valve body and it gives me full manual control using the stock valve body. If I put it in low it goes in low then and there. It still shifts like a normal automatic in "D" though too. I also used metallic clutches, heavy duty sprags and did a few other mods. Its pretty beefy and suits my truck fine. And Roy is correct about the internals being the same from the AMC case to the GM case.

As far as the 700R4, I think it'd be fine behind the 360 witht he weight of the 715. The stock gearing would help it live OK and with a good cooler I believe it will live fine. I've had good luck with them in other vehicles. Most of the bad reputation came from the first few years they were out, when there was somewhere on the order of 150 or more service bulletins with all the updates they needed.