904 Rebuild for Beginners

-
TJman

TJman

1975 Duster 318
Joined
Nov 16, 2016
Messages
37
Reaction score
19
Location
Grand Rapids, MI
I'm thinking about rebuilding my old 904 for street use. The videos make it look doable, and I plan on purchasing the manual by Tom Hand.
Question: > I can't seem to find good info about valve bodies. Is it typical to replace the valve body or rebuild?
> I don't see valve body rebuild kits online - I assume there are at least some seals that need replaced - do those parts just come with the transmission rebuild kit?
> What is a forward vs reverse vs manual, etc valve body (everyone seems to know but me)?
> Looking on Cope Racing Transmission website, they have racing, stock, street HP, and street kits. Should I stick with stock or upgrade? My teen is probably making 180hp, but I hope to upgrade and plan on ~300hp someday.

Back story:
I have a 75 Duster 318 that's pretty much all stock. 25 years ago, soon after I bought it, the transmission left me stranded - just sat there slipping and wouldn't go. Dad and I installed a used lock-up tranny and converter from an old Cordoba and off I went. It has started to slip in reverse, so I'm thinking about rebuilding the original transmission, which I still have sitting around. It has lived outdoors, etc., and I don't know the condition - only that it worked until it didn't and it's been sitting ever since. I use my Duster as a daily and I'm most interested in drivability and mileage, but I'll probably do a heads/intake/cam/carb job on it at some point.

Appreciate any advice or insight.
 
The book by Tom Hand is fabulous. If I was going to get anything else, it'd be the ATSG Service Group book on the Torqueflite.....but Tom's book is great. I've built several and if I can do it, it's well past "doable". LOL
 
RustyRatRod said:
The book by Tom Hand is fabulous. If I was going to get anything else, it'd be the ATSG Service Group book on the Torqueflite.....but Tom's book is great. I've built several and if I can do it, it's well past "doable". LOL
Click to expand...
Thanks. When you rebuilt them, did you rebuild the valve body also? I can't find much on that.
 
TJman said:
Thanks. When you rebuilt them, did you rebuild the valve body also? I can't find much on that.
Click to expand...
Not much to "rebuilding". I assume you're going with some kind of shift kit. I like Superior Products. They still sell Fairbanks kits. Any of the brand's kits come with good deestruckshuns so you'll be fine.
 
TJman said:
I'm thinking about rebuilding my old 904 for street use. The videos make it look doable, and I plan on purchasing the manual by Tom Hand.
Question: > I can't seem to find good info about valve bodies. Is it typical to replace the valve body or rebuild?
> I don't see valve body rebuild kits online - I assume there are at least some seals that need replaced - do those parts just come with the transmission rebuild kit?
> What is a forward vs reverse vs manual, etc valve body (everyone seems to know but me)?
> Looking on Cope Racing Transmission website, they have racing, stock, street HP, and street kits. Should I stick with stock or upgrade? My teen is probably making 180hp, but I hope to upgrade and plan on ~300hp someday.

Back story:
I have a 75 Duster 318 that's pretty much all stock. 25 years ago, soon after I bought it, the transmission left me stranded - just sat there slipping and wouldn't go. Dad and I installed a used lock-up tranny and converter from an old Cordoba and off I went. It has started to slip in reverse, so I'm thinking about rebuilding the original transmission, which I still have sitting around. It has lived outdoors, etc., and I don't know the condition - only that it worked until it didn't and it's been sitting ever since. I use my Duster as a daily and I'm most interested in drivability and mileage, but I'll probably do a heads/intake/cam/carb job on it at some point.

Appreciate any advice or insight.
Click to expand...
The valve body is all parts that just get cleaned, inspected for wear or damage, and then reused.

Do not buy a TCI kit or other like it. You have a Transtar Industries near your location in Grand Rapids. You can buy everything there individually so you are not buying a bunch of extra parts you won't use at a cost markup. But they can supply everything you need so end up with a "kit." And they will help get the right parts for you. Let them know it is your first time.

Do not buy everything before taking it apart and inspecting. Many of the bushings that come in some kits are not needed because they can be inspected for wear and re-used if in good shape.

Also, don't overthink it. If it is a mostly stock car you do not need a bunch of upgrade parts or racing clutch discs, etc. Stock replacement grade parts work very well.
 
RustyRatRod said:
Not much to "rebuilding". I assume you're going with some kind of shift kit. I like Superior Products. They still sell Fairbanks kits. Any of the brand's kits come with good deestruckshuns so you'll be fine.
Click to expand...
I'd figured it would be more than that, since the lockup in the car is slipping in reverse and the spare 904 was inoperable when I took it out. I was told that bands were burned out (or something).
 
TJman said:
I'd figured it would be more than that, since the lockup in the car is slipping in reverse and the spare 904 was inoperable when I took it out. I was told that bands were burned out (or something).
Click to expand...
It's a little intimidating if you've never done one, but just pay close attention to the deestruckshuns and you'll be golden.
 
RustyRatRod said:
It's a little intimidating if you've never done one, but just pay close attention to the deestruckshuns and you'll be golden.
Click to expand...
I'm not afraid to dig in and try. It's just hard knowing what parts or kit to buy. Maybe I won't know until I get it apart and look through the book. I'll contact Transtar - that sounds promising.
 
It is imperative that everything goes together CLEAN.

If you get a shift kit to install in the VB, be sure to follow the instructions carefully
and do not lose your balls.
 
i'd say blow apart the old 904 and see what you're working with. it might be trash, it might not but you'll at least have an idea of the inner workings and what you'll need to look for if it is.

and if it's not total garbage, then you've got a trans to install and go along on your way-- FYI though, lock up and non-lock ups take a different torque converter.
 
You must log in or register to reply here.
-

Back
Top