The Stovebolt Site Forums The Shop Area Engine Shop '54 Hydramatic transmission

I am helping a friend fine tune a two carburetor install on his '54 pickup with a 235 and hydramatic transmission.

The carburetor linkage at the bell crank on the block works in conjunction with linkage that goes back to the transmission.

I haven't worked on a rig like this before. The way that it appears to work is very strange.

I have done a search and didn't come up with much. Does the hydramatic not have a true torque converter?

What does this linkage do. It doesn't appear to be what I would call 'kickdown' linkage.

The owner of the rig says he dinked with the linkage and the transmission started slipping.

Any help would be appreciated.


Stuart

Boy, it's been a long time since I touched one of the old 4speed Hydramatics, but if my memory is accurate, the throttle connection is what regulates the line pressure in the trans.

More throttle, higher pressure, more clutch apply and firmer shifts. Less throttle, lower clutch apply pressure softer shifting. Misadjustment can cause too high pressure and harsh shifts or low pressure and slippage, especially when shifting or starting from stopped.

Hy guys, that lever connected to the trans. from the throttle lever is the transmissions throttle modulation. Without that connection the transmission would shift at the same road speed regardless of where the throttle was, basically the more throttle the later the transmission upshifts. As for the torque converter, no the hydramatic does not have one, it uses a fluid coupling. As for linkage adjustment I was taught that with the carb at full throttle the pin should just go into the lever on the transmission, hope that helps.

KENC,

You are the man. This is exactly what I suspected. I found a picture of the complicated linkage arrangement online, and a important spring is missing from the setup my friend has.

With the spring missing, the lash up makes no sense..with the spring, it does...now to find a spring!

http://chevy.tocmp.com/1929_57chevyparts/57cmpc0354.htm


Thank you for your help.

Stuart

3B,

It all helps...I do appreciate it.


Stuart

I am in the process of building linkage for my GMC with Hydramatic for the 2 carburetor manifold. It takes a bit of engineering, since I have Fenton headers and the manifold has the carb. flanges turned 90 degrees from the way the factory is. The linkage interferes with both the headers and the manifold. I am in the process of engineering a linkage that will clear everything also will be progressive, the 2nd carb will start to open when the primary is at about 1/2 throttle. Oh the fun of making hot rod stuff, reminds me of how we did it back in the '50's when there weren't hardly any aftermarket parts made.

chevman32,

Does your truck have the rats nest bunch of linkage at the block area where the bell crank is?

The truck I am helping with has Fenton dual exhaust and a Fenton 2X1 from Patricks. My knuckles are bloody and my arms are burned.

I guess I will need to find the torsion spring that wraps around the stud hanging on the side of the block, and does "something" that affects the relationship between the throttle linkage and the transmission linkage.


Stuart

Chevy and GMC use different linkage. I have the 54 Chev with HydraMatic and Offy dual carb intake. The lever you are talking about is throttle pressure. I don't know about a progressive linkage setup. Mine opens both carbs at the same time. With the throttle pressure lever pressed rearwards and the carbs set at idle, the linkage to the carbs should just go in. The throttle pressure lever is checked with a jig but shortening the rod that goes to throttle pressure lever lengthens the shift points and speeds up the downshift poit. It also harshens up the downshifts. Too long and it will slip and run thru all 4 gears in record time. Very small changes makes a big difference. Let me know if you need more info and I will see what I can e-mail to you.

Greg_H,

I would love more info. Anything at all would help.

Evidently this truck has been running around for quite some time without all the parts required to make the lever/linkage operable.

I am doubtful I will find the missing torsion spring, so I am formulating plan B.

It is not my truck, and I don't want to roast his transmission.

Thanks for your offer.

Stuart

Contact the B and M Racing guys. They know all about these old Hydra-Matics.

www.areds.com and talk to Leon

Give Tom Meyers a call, I have bought hydro truck parts from him before.

tom meyers
miami oklahoma
work#918-542-3871
[email protected]