Cruise O Matic MX odd problem - shift through itself - Wrong pattern, slipped down

[ced715]

I have a strange problem with a 1961 Thunderbird Cruise O Matic MX Transmission.

Just bought it a few weeks ago and seemed fine during the test drive.

Heard a strange story from the previous owner that the transmission slipped out of park and almost pinned him against the wall. He replaced the shift detent and shift lever, but then he said he found out that the transmission "shifted through itself" and when he opened up the transmission he saw "a shift lever was on the wrong side of a valve". I didn't really understand his story but since everything was working ok, I assumed he had fixed it.

Bought the car and pulled it onto the trailer and found out that it didn't seem to have a Park pawl. Thought that maybe the linkage was off or something but cash had already changed hands and title had been signed over. strapped it down and figured I would deal with it later.

I lifted up the car to take a closer look underneath after I bought it, and noticed that the "manual shaft and lever" that sticks through the side of the transmission had been welded at one point. That seemed strange to me but didn't think much of it.

Second drive around down, I've put about 20 miles on it, I came to a stop, put it in park, shut it off. When I started the car it lurched forward like it started in gear. Put it into Neutral quick and it went out of gear. Shifted into Reverse and also had a forward gear.

Long story short, with the gear shift in Park and Reverse the transmission was acting like "Low". With the shifter in the Neutral, D2, D1, and L positions, the transmission acted like it was in Neutral. The linkage on the outside of the transmission operated fine. With the linkage detached from the shifter arm, I could shift the manual shaft and feel the detent spring clicking inside the transmission with each position, so I figured it was the linkage inside the transmission.

I dropped the pan and found what I think the problem is. It seems that if I push up on the manual shaft I can bring it up high enough to move the control valve (is that the correct term?) freely in and out of the valve body without the manual shaft staying engaged with the control valve. What could cause that? There doesn't feel like there is slop in the manual shaft or the valve. If I drop the valve body, is there some kind of a lock that holds that in? Also, do I have the manual arm in the correct place on the control valve in the last picture? Or should it be all the way on the end? The first two pictures are how I found the arm when I dropped the pan.

Also I still cant seem to be able to engage the Park pawl. Should I be able to see it operate with the pan dropped?

Thanks for any help you can give

[bbogue]

In addition to posting here, you might also try posting your question on the Ford Transmission Forum on Tapatalk. Lots of knowledge over there as well. Good luck.


Bill

[ced715]

Thanks Bill, I posted over there too to see if I get a response.

Found this page in my shop manual. It appears I do have the manual shaft located in the correct groove of the manual valve in the last picture of my previous post. You can see the manual valve on the middle left of this shop manual page.

I will try and adjust the linkage with the pan off to try and see if I can prevent this from happening in the future. My guess is that it was adjusted so that if I held the column shift left of park that it raised the manual shaft high enough to allow the manual valve to move freely.

If someone has had this problem before or knows that I am missing something, please let me know!

Still wouldn't mind hearing advice on the park pawl and if I can see it operate or identify that it is indeed broken off with the pan dropped.

Thanks

[ced715]

Just a quick update, the transmission works normally again. I fixed the problem by adjusting the linkage that bolts to the manual shaft, on the outside of the transmission. With the pan dropped so I could see the linkage on the inside, I had a helper shift through the pattern to make sure the manual valve couldn't move freely. I paid close attention to the linkage when my helper was holding the gear shift as far as it could go to the left of Park position. With a bit of adjustment I was able to make it so the valve could not move freely.

I'm not sure if the welded manual shaft that I have is what allowed for the extra travel, but if someone happened to be messing around with the manual shaft linkage on the outside of the transmission, there may be a possibility they could adjust it so far that this problem happens to them!

Could not identify the park pawl, but I didn't want to dive too far into the transmission just yet. I'm assuming that it is broken or missing. I have a working e-brake which will have to do for now.

Keep 'em rolling
Ced

[Unseenentities]

Howdy. Any luck with your pawl?

[Jim Wulf]

I'm certainly no transmission expert, but here's a thread that shows a broken parking pawl and indicates it's position in the case. In the past, my transmission guy has replaced a broken pawl with no problem from underneath with the transmission in the car.

https://www.vintagethunderbirdclub.net/ ... hp?t=15181

[Jim Wulf]

Found this in a YouTube Video at the 38:09 mark:

https://www.youtube.com/watch?v=IipJF9iKyqA