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1950 Cadillac Hydramatic Issue - Stuck in Drive

Started by justin0949, January 01, 2021, 05:10:37 PM

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justin0949

I have a 1950 Cadillac 331 with the Hydramatic in it, and I recently pulled the motor and transmission to clean and paint. Rebuilt the engine, while just resealing the transmission to fix some leaks. Now once I reinstalled, the transmission is stuck in drive.. When shifted to Neutral it still drives forward. When shifted to reverse, it acts as if it is in neutral. Does this sound like a valve sticking? There is no neutral gear, and no reverse... Transmission has new dex/merc 3 fluid in it...Any recommendations? This transmission shifted great before the seal kit was put in.

Thank you

Mike Baillargeon #15848

Justin, I would start with eyeballing the shift linkage....maybe something got out of wack with the re-install of motor & trans...

Mike
Mike
Baillargeon
#15848

justin0949

Okay, thank you for the reply. I will double check. I manually put the transmission in neutral, and it still spins the tires forward, thats why I was assuming maybe the valve body needed cleaned or possibly the governor is acting up.

Thank You!

Jon S

Is this happening with the tires off the ground or with the tires on the ground?
Jon

1958 Cadillac Sedan De Ville
1973 Lincoln Continental Coupe
1981 Corvette
2004 Mustang GT

justin0949

Once engine was installed, I started it up and it drove forward while in neutral, so I shut it off and put it on jack stands and it does the same. Wheels spin at all times unless it’s in reverse. In reverse it acts as if it’s in neutral, and when you press gas it sounds like it’s going to die.

Jon S

I believe the wheels will spin forward even in Neutral when the back wheels off the ground. Anyone else care to comment?
Jon

1958 Cadillac Sedan De Ville
1973 Lincoln Continental Coupe
1981 Corvette
2004 Mustang GT

justin0949

There not just spinning a little, it’s in gear trying to accelerate forward fast. For some reason it’s stuck in drive gear :(

Jon S

 have you tried disconnecting the linkage and manually turning the selector on the transmission ?
Jon

1958 Cadillac Sedan De Ville
1973 Lincoln Continental Coupe
1981 Corvette
2004 Mustang GT

justin0949

Yes sir. I disconnected the shifter and manually put it in neutral, same result. It spins the forward like it’s in drive. I’ve never seen anything like it lol

savemy67

Hello Justin,

Your post indicated you pulled the engine and transmission.  Did you pull them as a unit, or did you separate them before pulling them?  If you pulled them as a unit, did you use a load leveler on your hoist and have to attain a steep angle to remove the unit from the car?  Or, if you separated the engine from the transmission, did you drop the transmission from under the car?

Your post mentions you resealed the transmission.  Exactly what was done to reseal the transmission?  What were the contents of the seal kit?  Did you do the work yourself, or was it done at a shop?

If I recall correctly, if you push the manual valve lever at the side of the transmission (with the column linkage disconnected) all the way to the forward (front of car) position, you will be in the Neutral detent.  The first detent rearward is Drive, the next detent rearward is Low, and the last detent rearward is Reverse.  When you moved the lever by hand, did you feel all four detents, and feel them robustly?

This vintage Hydra-Matic will exhibit forward creep in N, but generally not enough to accelerate the car unless the idle is very high and the bands are not adjusted properly.  What is your idle speed in Drive?

You could drop the bottom pan to check that the link from the manual lever to the manual valve has not fallen out of place.  If the link is connected to the valve it is not possible for the valve to get stuck.  If it was stuck, you would not be able to move the lever at the side of the transmission, nor the shifter on the column.

The fluid should be OK, unless something in the transmission was on its last legs, or something got dislodged by use of the newer fluid.  Let us know what you find if you drop the pan and examine the manual valve link.

Respectfully submitted,

Christopher Winter
Christopher Winter
1967 Sedan DeVille hardtop

Bobby B

#10
Quote from: savemy67 on January 01, 2021, 09:27:37 PM
Your post mentions you resealed the transmission.  Exactly what was done to reseal the transmission?  What were the contents of the seal kit?

Yes, This is Key. What EXACT gaskets/ hard parts were replaced and where was it leaking from? Was the valve body removed or dis-assembled at all? If you removed/split the valve body or removed the internal shifter mechanism,  it's very easy to get it re-installed incorrectly, rendering it in-operable. Trans does move in neutral on Jack stands, but you need to retrace your steps if it's actually in Gear in Neutral. Did you touch the pressure regulator assembly or the front intake pipe from the pump to the servo? Did anyone fool with the reverse shifter bracket/ reverse shifter crank? Please more info on EXACTLY what was touched, removed, or dis-assembled. I can point to 100 and 1 different things unless I know what was done.
                                              Bobby
Did you fool with any part of this?
1947 Cadillac Series 62 Convertible Coupe
1968 Mustang Convertible
1973 Mustang Convertible
1969 Jaguar E-Type Roadster
1971 Datsun 240Z
1979 H-D FLH

fishnjim

Clarify: in reverse it acts like neutral?   ie, wheels freely turn backward and forward or forward only?
If it didn't have this condition before, then something you did during the take out and put back is the cause.
Sounds like a check the fluid level and the linkage adjustments, first.   Not sure what you did to "seal up the trans" that could've caused issues but don't that rule out.

justin0949

Thank you everyone for the replies. I have found the issue. Over the weekend, I pulled off the side cover and found the manual valve in the valve body was not connected to the external shift linkage pin; therefore, causing it to be stuck in drive. Thank you for the help!

Bobby B

Good Deal! That's what I figured and that's why I sent you the pictures of the valve body for reference. That's a common overlooked issue.
                             Bobby
1947 Cadillac Series 62 Convertible Coupe
1968 Mustang Convertible
1973 Mustang Convertible
1969 Jaguar E-Type Roadster
1971 Datsun 240Z
1979 H-D FLH

Joe Jensen

I did the exact same thing on my transmission.  Sorry, I didn’t see this sooner.  I might have saved you some time.

Good luck!

Joe Jensen