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That sux man.. Well, look at is as an opportunity to upgrade.. A fresh R&R on the T400, throw a shift kit in it and maybe a small stall speed converter to wake the car up... May as well make lemonade out of a lemon.
Remember to have your stock converter cut opened and cleaned if you decent not to upgrade to a new converter... Any metallic material from the hurt trans is stuck in the converter so its important to get it cleaned.
That sux man.. Well, look at is as an opportunity to upgrade.. A fresh R&R on the T400, throw a shift kit in it and maybe a small stall speed converter to wake the car up... May as well make lemonade out of a lemon.
Remember to have your stock converter cut opened and cleaned if you decent not to upgrade to a new converter... Any metallic material from the hurt trans is stuck in the converter so its important to get it cleaned.
Thanks ajrothm ... yeah ... this '74 has been quite the sleeper with the LT-1 that's under the bonnet and I want the tranny to keep the quick shifts it had ... pretty sure it already had a shift kit. When it's torn down will someone knowledgeable be able to tell what converter, shift kit & any other mods are in it? Really would like to keep it close to what it was as it was really sweet ... shifted normal under light accel. but quicker the harder the acceleration.
It's interesting what you said about the TC & debris. I never heard that before until today when I was asking around about who to take it to and I got warned about exactly what you mentioned ... makes sense.
Truthfully, the hardest part of rebuilding a th400 is removing it from the car. They are super easy to rebuild with common tools and there is a great book out by Ron Sessions on how to rebuild. I don't know how adventurous you are but you might want to think about doing it yourself. Get a quality rebuild kit and a 34 element sprag, new bushings are a good idea too but I think you'll find that most if not all are still fine.
Truthfully, the hardest part of rebuilding a th400 is removing it from the car. They are super easy to rebuild with common tools and there is a great book out by Ron Sessions on how to rebuild. I don't know how adventurous you are but you might want to think about doing it yourself. Get a quality rebuild kit and a 34 element sprag, new bushings are a good idea too but I think you'll find that most if not all are still fine.
Either way, good luck!
Thanks dugsgms ... I checked out the book on Amazon and it's really got great reviews. I'm fairly handy and generally good at following instructions but I figured it would require experience to tackle an TH400. How did you handle the cleaning out of yours?
Not what I call a fun job but I got it out and have prices from several recommended places for a rebuild. Plan to touch base with each one on a couple of details and then make a decision but expect to take it in Monday. Hopefully this will get me past this transmission issue so I can finish Vette.
When you're talking to those shops, remember that a full overhaul kit, (faced clutches, new steels, bands, and all the gaskets and seals) can be had for under $200. Add a quality Trans-Go shift kit and you're still about that same money. Rebuilt convertor adds about $125. And with some time, the desire, and some thinking, a 400 is a really easy rebuild. You have the book and you can see what it takes.
Add that 34 element sprag- well worth the money. Sometimes you have to replace the direct clutch drum to use it, GM changed the diameter of the inner sprag race somewhere in there.
NAPA sells the TH400 automatic transmission kickdown switch/solenoid for $25.00. It is part number "S636". If you drop the tranny pan and follow the wire from the accelerator pedal to the tranny body, then into the tranny, you will see the relay/solenoid. The NAPA part description shows a picture. The relay diverts fluid within the tranny via an orifice. The relay may click but the orifice may be clogged, etc
I had the same issue with my '72 a few years back.
Good luck
Thks TimAT and JimT for your input. If I were going to keep this Vette I would tackle the rebuild myself but I hope to sell this car once it's finished and I think it would be better to have a receipt from a good re-builder than to say I rebuilt it myself and it the first one I've ever done.
Believe me the only reason I'm planning to part with this one that I've owned since '83 is so I can start the re-conditioning process on my '67 Coupe which I plan to keep. Wife frowns on me having two toys!
12-10-2014, 06:04 PM
toys!
X10!