Manual valve body?

[tequilaiam]

Has anyone installed one of these in their tranny to make it act like a clutchless manual?

I'm thinking about this as a way to simplify and maybe extend the longevity of my tranny. I don't do much in-town driving so it could be worth it if it will cut down on the number of potential things that can go wrong. I'd like to hear if anyone has installed one and how it shifts. Is it really rough and abrupt or smooth but just not automatic?

 

[dependable]

If you don't want any problems, don't mess with it if it is working. Its a Turbo Hydramatic 400. Replace the filter, change the fluid, check modulator if you want. These are reliable units, no computer, well built ect.

 

[mikes47jeep]

get an aftermarket transmission cooler, a big one

overheating is pretty much the only think that kills TH400's

and just keep up with you fluid and filter changes the book says every 25000 or something like that

but i go by fluid color and smell, if its dark or light or smells burnt it gets changed

Mike

 

[Anubis8472]

The toughest part of rebuilding these transmissions is pulling it out/putting it back in the vehicle.
Once it's on the bench anyone can do it.

The manual conversions are really just for 'drag strip' applications, and you're not really bypassing anything that's going to be an issue.

As for the actual shifts, they would be the same unless you are also changing pump pressure/springs etc. Provided you shift at the proper speeds.

If anything I would say that in most cases this sort of modification would only lead to a reduction in the transmissions longevity by introducing inconsistant shift points.

As stated above, best thing you can do is a good trans cooler and proper maint.

 

[tequilaiam]

If you don't want any problems, don't mess with it if it is working. Its a Turbo Hydramatic 400. Replace the filter, change the fluid, check modulator if you want. These are reliable units, no computer, well built ect.

It's not unfortunately. I went from one issue (not holding 3rd gear)
to a new one (doesn't want to upshift unless I move the detent down then up) after replacing fluid, filter and modulator.

I'm thinking one of the valves moved by the governor or modulator is stuck, which is why I asked....if I'm going to pull a valve body or get this thing rebuilt (gulp) I wouldn't mind just elimating the need for a governor, modulator, vacuum or any other stuff on the condition that nothing else gets prematurely worn, stressed, over-pressurized or what have you.

 

[Tanner]

How long do you plan on keeping the truck? Keep the transmission stock, with all the required bits in it so that it operates as it was designed to do. If the plan is to keep it for a long time, as in 10 years plus, then get in touch with Jasper Engines & Transmissions & get a reman TH400 - 3 year/100k miles warranty, dyno-tested & a quality unit. It's worth the money to do it once. Add a cooler kit (if I recall, they can sell you a matching cooler as well to go with it, and cooler should also be covered under their warranty period).

Compare:
'X' cost to bandaid your existing transmission & fix a few issues to get it rolling with unknown worn parts inside.
'Y' cost to get a transmission shop to overhaul it & give you a minimal warranty (if any) & it gets 'road dyno-tested' after it's installed back in your truck. BTW, they clean the parts & put 'em back in without knowledge of the 'reusable' parts being within GM factory specs...
'Z' Cost to buy a quality reman unit that has had the used reusable parts checked & verified as being within tolerances to be used.

And for the record: I'm not a shill for Jasper, but I've sold & installed, and run their products & had exceptional results from them.

Good Luck!

'Tanner'

 

[tequilaiam]

Thanks for the suggestion, Tanner. I completely forgot about Jasper. So here's an additional question: do the 'hard parts' inside these things ever really wear out or get out of spec? I was under the impression that an overhaul replaces all the seals, friction bits and anything else not metal and that was as good as new.

With the holidays approaching and the weather guessers and local catterpillars indicating a lot of snow this winter, I'll probably just band-aid the thing until spring when I can get around to removing the tranny and getting a remanned one or do a SM465/205 swap. Good suggestions though. I'll definately price out a jasper unit.

 

[Jersey4x4]

if you let it warm up for about 10 min or so will it then shift?