64' Plymouth Valiant v-8 Push Button - Torqueflite Linkage or ???

[HotWheelsGarage]

Happy to say I bought my first convertible, Plymouth Valiant Signet 200, and have had a ball driving it. Loving every minute of it until yesterday when the push button transmission failed. Push 1 - all good. Push 2 - no problem. Push D and it was not catching and no acceleration. Drove home in first and second.

Dad is a hot rodder who suspects linkage issues, but we would love your thoughts on what it might be and if it is something we may be able to crack ourselves? He is a car guy, with a lift, but at 83, might be wiser to get as much info as we can before going in. I'm a daughter with very little mechanical knowledge, but just love working on cars with my dad who is teaching me bolt by bolt.

Any thoughts are appreciated. Feel free to explain like I know nothing because I know nothing about this!

Thank you!

 

[AJ/FormS]

IMO, it's really doubtful to be the linkage, but, in the interest of being thorough;
How does reverse work?

The reason I ask is because, to get reverse, the trans uses the L/R band, and the 3rd gear clutch; which is also called the Hi-drum, or in Moparese, the front clutch. So then, if reverse works, then we know that the Hi-drum is ok. and if that's true, ok, I concede that you could be having a linkage problem.

Then again, are you sure that it's hi that you are missing?
Tell me again what happens in "D", from a stop.. OR
If you have a tachometer, what was your rpm in "2" on the hiway? and did it take off as normal in "1"?

What I'm trying to figure out here is if the KD mechanism fell off the carb, and the trans is just upshifting really fast. or if the governor is working.

 

[Bewy]

See ifyou can lie under the dash & get your hand on the shift cable [ or you might be able to see it ]. Get a helper to push the push buttons & you should feel the cable move with each shift increment. No movement might indicate a push button fault, but it could also be inside the trans.

 

[HotWheelsGarage]

IMO, it's really doubtful to be the linkage, but, in the interest of being thorough;
How does reverse work?

The reason I ask is because, to get reverse, the trans uses the L/R band, and the 3rd gear clutch; which is also called the Hi-drum, or in Moparese, the front clutch. So then, if reverse works, then we know that the Hi-drum is ok. and if that's true, ok, I concede that you could be having a linkage problem.

Then again, are you sure that it's hi that you are missing?
Tell me again what happens in "D", from a stop.. OR
If you have a tachometer, what was your rpm in "2" on the hiway? and did it take off as normal in "1"?

What I'm trying to figure out here is if the KD mechanism fell off the carb, and the trans is just upshifting really fast. or if the governor is working.

I really appreciate your help and your questions because I didn't know where to start. The Valiant is at my dad's house so I'm going to ask him to check reverse, which we both noticed was a hard shift into yesterday. Clunking shift so that's worrisome. If he can also perform some of those operations, I'll get that information your way as soon as he gets it my way.

Sorry to not have all of that info sooner. More to come!

 

[HotWheelsGarage]

See ifyou can lie under the dash & get your hand on the shift cable [ or you might be able to see it ]. Get a helper to push the push buttons & you should feel the cable move with each shift increment. No movement might indicate a push button fault, but it could also be inside the trans.

Thank you so kindly for the suggestion! I will have my dad give that a go this evening when he's with the car and will get back to you. I really appreciate the time and help. More to come!

 

[HotWheelsGarage]

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Okay update is that dear old dad is taking the car to his transmission guy because he knows how much I love this car. Didn't have time to drive it or do any diagnostic, but says he will get more info soon so apologies for not having anything solid to report.

 

[65 Dartman]

Your 904 is proably going to need some internal work to fix it. Taking it to a knowledgeable transmission shop is probable a wise move.

Although a 904 is relatively easy to work on, I elected to take my 64 904 (which was a loose transmission) to Dynamic Converters for rebuilding and replacing the front drum/input shaft to accept 68-later torque converters and build a torque converter for me. Eventually my 904 will be giing in my 47 Dodge