I've posted about this issue in the past and I thought I had it resolved. It would appear I do not as it has reared its ugly head again. 

My TH400 in the 64 Fleetwood has an intermittent problem of not shifting into 3rd. I have tried to replicate it the best I can but can find no pattern to why it is happening. 

So far I have cleaned and checked the gov gear and replaced that seal as well as a new vacuum modulator. 

My suspicion now is that it is temp related. 

I have had my Fleetwood out and about since early March. Its been a rather cold spring here in C Illinois. Today was a high of about 85. I went to the gas station and to the car wash. As I was headed home, the temp gauge was level with the second mark. This is the warmest the engine has gotten this year. I noticed a late shift into 3rd. After I had stopped at a stoplight and proceeded forward again, no 3rd. 

I then drove around in the country for about 15 miles. Sometimes it would shift like butter, others it wouldn't shift until I accelerated past 60mph and then coasted. Then it would shift around 50 mph. 

I am completely stumped and have no idea what this issue is. 

I am going to order a new filter and gasket and see if maybe it is a fluid issue. I am meticulous about keeping the fluid level correct as mine has a slight leak. So fluid I know is always topped up. 

Any suggestions on what's next besides a rebuild would be greatly appreciated. 


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Hi Logan

Have you checked that the valve inside governor moves freely? That valve is essential for operation of governor. My bad I forgot to mention that last time.


I did! I have had the governor completely out and made sure the valve was moving freely. Truth be told, I don’t recall now if I had the valve out of the body of the gov or just cleaned it really well inside and made sure it moved freely. 

When I do the filter and gasket, I may pull the gov again just to be sure it’s clean and functional. 

If you cannot get it right, and do not want to cough up the big bucks for a complete rebuid, I have about 18 1964 Turbo Hydramatics, of which 3 or 4 are for parts, about 5 from running, shifting cars.  I sell the better ones for $250. Change fluid, filter, & gasket and front and rear seal and you will be good to go. Price is $250 and you would need to provide transport but I can give you the details of working with Engines Direct Shipping which has shipped dozens of engines and transmissions for my customers at reasonable prices over the years. Here is a picture of my current stash of 64 THM's:

I may take you up on this. I have no desire to keep the original trans if it’s going to give me fits….

Had the 64 out and about again today to give the A/C a go (I'll post about this later) and as soon as the engine temp makes it just past halfway, that is when I start having this issue. 

I can force it to shift into 3rd SOMETIMES by stopping the pedal all the way to the floor and that will kick it to 3rd, sometimes. This is obvisoly NOT good for a 60 year old motor, but it got me home at more than 30mph lol. 

Thinking the ol girl will stay garaged a while until I can acquire all new seals and filter. I am hopful that will solve the issue. 

Since I am hedging on temperature, I am wondering if maybe the trans cooler is bad? Is the A/C condenser and trans cooler all one?

Thanks all



The trans cooler is at the bottom  section of the radiator 

Nothing to do with the AC 

You can follow the lines from the trans to the rad 




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