1959 Transmission Problems

[howelljason70]

I recently acquired my first Squarebird. When I bought it there was a knocking sound coming from somewhere in the engine compartment. At first I thought it could possibly be a loose wrist pin. The symptoms were a moderate knocking noise in a relatively rapid succession. This would only happen at idle, and primarily when it was placed in park. I soon realized though (to my relief) that when I applied a little pressure to the downshift linkage the noise completely disappeared. I have since adjusted the linkage, and the noise is gone. It does still clunk/knock a little when I place it into d2 but very rarely. The problem now is that there is a buzzing noise coming from the transmission. I have not driven it yet so I do not know if my adjustments have affected the shifting points but I would like to resolve this problem before I drive it.
Any experience or insight to this issue and what is actually going on would be very helpful.

[simplyconnected]

With all 'unknown' situations, why don't you troubleshoot? Be sure all your fluids are topped off. Put the car on stands and try it with your foot on the brake. Ease it into different trials. Have someone else hold the brake while you look underneath. Or, have a mechanic look at it.

[howelljason70]

Thank you for your reply. I have done quite an extensive amount of troubleshooting pertaining to the situation. I have narrowed it down to it most likely being a problem with the throttle valve causing an improper pressurization of the friction plates. I am trying my hardest not to have to take the car to a mechanic and am merely wondering if anyone else has had a similar situation with the Cruise-O-Matic transmission. Thanks again!

[simplyconnected]

The biggest problem I had with mine was dirt (after all those years). I rebuilt mine last year, nothing wrong with the valve body. Here are some pic's. - Dave

[bird 60]

Hi Jason,

I've had the buzzing sound for quite some time now & it's still buzzing.
I've been told that it's nothing to worry about that it's trapped air in the Trans.
Mine only does it in Reverse when first starting from one day to the other for a few seconds. During the rest of the day no Buzz. I don't Know if it would do in the forward gears as it's garaged & reversed out only. I also had a knocking sound that seemed to come from the Trans but only when driving. It gave the impression that a chunk of the Flex-Plate had broken or a Bolt rolling in the housing.
Took it to the Mechanic & found the front Universal joint had sh@#%t itself.

If someone else comes up with a different reason for the buzz please let us know.

Chris....From the Laqnd of OZ.

[howelljason70]

Thank you guys for all of the help. Perhaps I will flush the transmission and see if there is any debris or dirt. Today I experimented around a bit more. The sound that the transmission makes is very specific to the position of the throttle valve/linkage. When the lever is adujusted up (the linkage being adjusted in) it makes the knocking noise, which sounds like it is coming from the torque converter. When the lever is down it makes the buzzing noise (sounds like a power steering pump being over extended). Is it possible the throttle valve is a little loose and causing improper pressurization? Again these noises are very specific to the position of the throttle linkage. Thanks again for all of the help!

[Astrowing]

I would get a pressure gauge/hose and check the transmission pressure. It should be 56-68 psi at idle in D1 and D2 and 80-85 psi when you go up to 1000 RPM (again in D1 and D2). The throttle linkage (bellcrank) can be worn out and will keep you from making a good adjustment. The pressure needs to go up immediately with an increase in engine RPM. I suspect that the friction plates in the clutches are slipping and making your noises.

[howelljason70]

Where would be the best place to attach the pressure guage? Is there a way to tighten the throttle linkage or the shaft the linkage attaches to?

[Astrowing]

The pressure port is 1/8" NPT and is located on the back left bottom side of the transmission housing. Get a hose extension also so you can have the gauge up where you can see it.

[Astrowing]

In terms of adjustment, you can disconnect the clevis where the throttle rod connects on top of the engine. Lengthen the rod by rotating the clevis counterclockwise to increase pressure. Shorten the rod by rotating the clevis clockwise to decrease pressure.

You still may have clutch damage that will eventually have to be addressed, but this is a start. Don't forget to drain the torque convertor also when you change the fluid.

[Guest]

Don't forget that line that's at the back of the manafold was to test the trans. Not sure what was being tested?