View Full Version : 59 TBird Transmission

01-19-2015, 05:17 PM
Hi all,
The transmission in my 59 Bird is leaking at the seal where the linkage goes into transmission. Appears you have to drop all the guts out of trans. to fix it. Since it is not the original transmission (no tag on it, but case has C3TP-7006A stamped on it which I understand means the case was for a 1963 truck, but that the trans could have been used in a car), I'm thinking about either finding an original 59 trans or upgrading the trans to a C4 or C6. Does anyone know what transmissions will fit a 59 Bird with the original 352? I do have the original bell housing.

01-19-2015, 08:25 PM
You can use a C6 but you will have to modify the trans mount. I wouldn't recommend a C4. They were used mostly with small block motors. Replacing the front seal is easy once you have the transmission out. You don't have to take anything out but the torque converter.


01-20-2015, 12:27 AM
Thanks for the information John. The front seal in my current transmission is new as is the rear seal where driveshaft connects to trans. The one that is leaking is the one inside the transmission where the shifting linkage is attached. Do you know if that one is difficult to replace?

01-20-2015, 01:53 AM
There are actually two O-rings for the shifter linkage. You have to remove the valve body to get access to the shafts. It's difficult with the transmission in the car because there's very little room to pull the shafts out. I had my local garage do the last one and they charged me about $180. Without a lift it's difficult but doable. The seals are only a couple of dollars.


01-20-2015, 03:02 AM
Guess I should have checked the TRL first. The procedure is also there and the pics are better. Here is a link: http://www.squarebirds.org/picture_gallery/TechnicalResourceLibrary/TrannyShiftSelectorSeals.htm

I had the same problem and replaced the 2 o-ring seals laying on my back under the car. Not a nice job but it was doable. Here is the procedure I found on line to do it:
1. Remove the two curved tubes that are in your way.
2. Remove the four 7/16" head bolts that hold the valve body together. (Do NOT remove the three 7/16" head bolts that hold the valve body to the case yet.)
3. Remove the four screws that hold the valve body together.
4. CAREFULLY slide the valve body section that is now loose off of the two straight tubes. (Make sure that you slide the metal spacer plate along with it. Be VERY careful to not lose the checkball that is often inside this valve body section.)
5. Now you can take out the three bolts that hold the valve body to the case and the valve body will come out.
6. You will need to remove the 1/2" head nut on the end of the kick-down lever, but make sure you hold the kick-down arm when you do this instead of torquing against inner lever. It breaks off VERY easily.
7. Remove the nut on the end of the manual lever (inside the case). When you do that, be very careful. There is a spring loaded detent in the case. DO NOT let it shoot out.
8. Pry the old manual seal out of the case.
9. Install the new one by using a hammer and an appropriate sized socket as a driver.
10. With a small screw driver, pry the kick-down seal out of the manual arm.
11. Install new kick-down seal.
12. Reverse procedure to reassemble. Make sure the detent is riding on the detent notches.
13. Make sure the manual valve is engaged into the manual lever and that the kick-down lever arm (inside the case) is between the stop and the kick-down valve.
14. Install the three 7/16" head bolts that hold the valve body to the case and torque them to 65 inch-pounds.
15. After sliding the valve body section back onto the two tubes, make sure you start all four screws and all four bolts BEFORE you tighten any of the eight.
16. Tighten the screws snuggly and the 7/16" head bolts to 65 inch-pounds.
17. When you are done, verify the operation of the manual lever and the kick-down lever. You should feel the detents when you move the manual lever AND you should feel the spring pressure when the kick-down lever pushes the kick-down valve.
It is not as complicated as all of this sounds and using this method, you don't need to remove the servos.

If my memory is correct, I think I got the seals from Rock Auto and as John said, they are only a couple of dollars.

I also think I had to lower the rear trans mount to get enough room to remove the shift shaft, but I couldn't swear to that.

01-20-2015, 05:32 AM
When prolonged years of heat work on these 'O' rings, they fail. It seems like every transmission shop will do what they can NOT to change these 'O' rings. The procedure isn't very hard but it can be tricky.

Look through my transmission rebuild site for real pictures:
CLICK HERE (http://home.comcast.net/~simplyconnected/projects/Cruise-O-Matic/default.htm) - Dave

01-31-2015, 09:15 PM
Thanks guys, this information is very helpful. I found the other information in the TRL also. I have the transmission out of the car now. I am debating on whether to replace the 'O' rings or just send the trans out and get it gone through. From what Dave says about transmission shops, I may need to do both!
Dave, I have some questions about your transmission pictures. What year is that trans and what did it come out of? I'm interested because it looks like a 14 bolt pan and the gasket looks like the one I had to buy to fit mine (59 Tbird gasket will not fit). I also didn't see a vacuum module on your trans. Does yours have one and if so where is it located? Thanks again.

01-31-2015, 09:48 PM
I believe that transmission was from Dave's '59 Galaxie. It does not have a vacuum modulator as they weren't available until 1961. I'm not sure where you got your original gasket from as all Thunderbird cruise-o-matics have a 14 bolt pan.


01-31-2015, 10:42 PM
John is correct. This 3-speed C-O-M came from a 1959 Fairlane. A guy in Massachusetts was parting out his car and co-incidentally my wife wanted to change her stick shift '59 Galaxie to an automatic.

I only wanted the trans swap parts but he insisted that the engine and trans were still together and he wanted to sell them as such. Well, ok. Another 'unknown' 292 Y-Block engine and an 'unknown' trans. So, I bought these parts to rebuild.

Two pallets arrived at our suburban Detroit home with a, steering column, driveshaft, brake pedal support, and linkage on one and an engine and trans on the other. In short, everything I needed to transform to an automatic. Everything bolted on.

I got my trans parts from tee-bird.com, for a small-case 1959 C-O-M with NO modulator. I also ordered fibers and steels but ended up using the original plates because they looked like new. The trans only needed one brass bushing and all new gaskets and 'O' rings.

After overhauling the engine and trans, the car runs beautifully. I installed an electric wiper and power disk/drum brakes. - Dave

02-01-2015, 12:02 PM
Thanks again guys.
John, I think the 14 bolt was just confusion on my part as I saw a 15 bolt pattern on one parts store's site. When I order a pan gasket for my 59 bird with 352 from, say Birds Nest, the only option I get is a gasket exactly like ATP part number FG2 which does not fit the transmission I have. I assume this is because I have a newer transmission (at least a 1961 as you say because it has the modulator). So, it appears to do just have a newer C-O-M. I measured the case and it is 9 7/8" so it looks like a light duty. I have some pics, but can't see to find out how to upload them. Will work on that.
Thanks again. Tom

02-01-2015, 12:16 PM
Does your fill tube go into the pan or into the case itself.


02-01-2015, 01:56 PM
Hi John,

It goes into the pan.

Attached are some pics:
First one is the gasket that fits.
Second one is the gasket I get when I order one for a 1959 bird with 352.
Third is a pic of modulator value.
Last one is a pic of one of the servos which has a crack in it. I am wondering if that is a problem.


02-01-2015, 03:40 PM
Yeah, the second gasket definitely looks wrong. For some reason parts dealers have trouble getting the correct transmission kits for the MX/cruise-o-matics. I never have been able to find the correct filter. I always have to reuse the old one. As for the servo maybe Dave would know. I imagine it will get worse over time. Other than the modulator valve the transmission is pretty much identical to the original '59 transmission.


02-02-2015, 02:11 PM
Thanks for the information John.
Dave, would you be able to provide me any information on the servo (crack) and should I hook the modulator up to my vacuum or just cap it off?

02-02-2015, 04:58 PM

You MUST hook the modulator up to engine vacuum or it will not shift correctly.