727 transmissions are so complex

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Kent mosby

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I have been studying the books from Munroe and Hand. The information is so overwhelming that I hesitate to begin an overhaul or rebuild. Can you give me a great reason why I should do this myself instead of getting a TCI trans and call it good?

I am building 500+hp 512 ci stroker for my 73 scamp. I was a machinist for 12 years in my past life so i can do it. But why would I want to?

The options are to spend $600 for the kits to rebuild and replace the valve body for strip use.
Or to buy the TCI trans to do it for me. What does your wisdom say??
 
$600?!?!?! You want to do it to prove that you aren't afraid. Remember, "It takes steel balls to rebuild automatic transmissions".
 
It's only overwhelming because you haven't read or studied the books enough like you read and studied back in school. If you really want to tackle it yourself, read, read again, then read again until you literally can lay in bed with your eyes closed and go through the steps of disassembly and reassembly. I used the Carl Munroe book too, but also the factory service manual and did exactly as I mentioned. When I actually started on the trans it was a piece of cake. Biggest concern was making various improvised tools vs. buying the specialized ones. But if you can "make tools" the rest is elementary. Go study :thumbsup:
 
As far as automatic transmissions go the 727 is on the simple side, and it can be a rewarding experience to go through one. I like the “steel balls” post. I’m gonna pass that on
 
I was told the 727/904 was the easiest auto to overhaul.
Did my first one 35 years ago, folliwing a petersen service manual. I still have that manual.
 
do a google search on TCI maybe there quality is better now . cope would be my choice .
 
It seems hard until you watch a few disassembly videos from YouTube, and start taking it apart yourself. Then it's like this is sooooo easy! Did my first one in 1977, a stock tranny I was using for racing. I had only put a manual valve body in it. Well that stocker was good for about 100 passes before the high clutch went out. Bought a hi perf rebuild kit for $75, put that in, and it worked great! It contained new bands, clutch friction discs, and rings for the pistons. (Servos?) If you are a machinist with mechanical knowledge, you should have no problem. Just take your time. I converted a stock valve body to a manual one a few years back, and that was tricky. So I studied the trans go kit instructions over and over, then it wasn't too bad. Re build the trans first, then either buy or re do your valve body as a separate project. That's a little harder. Why do it yourself? For the satisfaction of knowing you can, and knowing exactly how that thing works. Good luck!
 
Maybe you should buy the racing trans and rebuild a stocker for some little old lady or a single mother, first.
 
I also put a stock 727 in my RR, using the valve body I modified. That worked great for years, making many low 12 second passes, as well as being driven on the street a lot. The torqueflite is a well designed, heavy duty unit, even in stock form. Just be sure to adjust the bands properly. By adjusting the kickdown, or front band, a little tighter you can tighten up the 2-3 upshift. But you have to be careful as the hi clutch and front band overlap briefly during the shift . As the front clutch applies, the front band is releasing.
 
Wow your overthinking this. The 727/904 is the easiest transmission I have ever been into. You can do it, it's not hard at all. Just watch as you take it apart and follow the book. Have a clean uncluttered work bench. Like said above there are videos online to help. You will need a few special tool to get the drums apart though. TCI would not be my pick. You can do better then them on your first rebuild. Go for it! :thumbsup:
 
Well, I guess I have been overthinking this. Good to see that many of you think this is easier than I think. Since it appears that TCI is not well trusted, where would you buy a rebuild kit? Cope?, transgo for the valve body, any others? Thanks for the encouragement. I thought I was making a mistake even thinking about doing it myself. Now I am confident that I can do it well. Thanks
 
Kent mosby said:
Well, I guess I have been overthinking this. Good to see that many of you think this is easier than I think. Since it appears that TCI is not well trusted, where would you buy a rebuild kit? Cope?, transgo for the valve body, any others? Thanks for the encouragement. I thought I was making a mistake even thinking about doing it myself. Now I am confident that I can do it well. Thanks
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I always recommend that you buy it somewhere local because there are so many parts it's easy for them to miss bag them and then you end up having to mail back and forth. They're all going to be was in a $20 price range likely so getting one that's convenient and close to you is best.
 
You and get a transgo or B&M kit and use the valve body you have. Both of them make easy to install shift kits. Any auto parts store will have or can get a transmission overhaul kit.
 
I have a stubborn 727 in my 72 Duster that will not shift into 3rd gear. I had a TCI manual valve body put in it and have had it built by what was supposed to one of the best shops in the area. With the car on jack stands, I can go through all the gears and feel positive feedback at all the positions on the indicator. However, soon as I get the car on the ground and drive it, it will not shift into 3rd. Any thoughts? It’s going back to the shop this Friday when I’m off. Thanks!!
 
jimjimjimmy said:
do a google search on TCI maybe there quality is better now . cope would be my choice .
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.
I have a TCI SB Streetfighter. Got with my 73 Duster. I was told it was good to go.
However, later when getting ready to use it, I opened it to change the filter and adjust the rear band. Surprise surprise it was full of chunks of metal and lining material. Someday when I get over being mad about it, I will rebuld it. Was told the metal chunks probable came from the converter also a TCI unit.
In the meantime I have a built 904 and 727 copying Cope Racing Transmissions.
The 904 is a copy of John's race version, only I put a Griner valve body with low band apply in it. And the 727 is just like the one that was mentioned above that SG uses. Only I used a turbo action cheetah valve body in it.
 
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Brennon McGuire said:
I have a stubborn 727 in my 72 Duster that will not shift into 3rd gear. I had a TCI manual valve body put in it and have had it built by what was supposed to one of the best shops in the area. With the car on jack stands, I can go through all the gears and feel positive feedback at all the positions on the indicator. However, soon as I get the car on the ground and drive it, it will not shift into 3rd. Any thoughts? It’s going back to the shop this Friday when I’m off. Thanks!!
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What MPH on the stands does it go into 3rd, and what MPH on the street, Governor maybe?
 
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