Seafoam Hydra Trans Tune

[Fleetwood Meadow]

My ‘52 Cadillac doesn’t shift. It has the 4 speed dual range Hydra-Matic in it. The car hasn’t run since 1976 and I got it running for a couple miles and now it won’t shift out of first. I’ve heard many suggestions as to different technical things that it might be. I’ve checked the governor, I’ve checked the control body. It still doesn’t work. There is a place that I am going to send it soon but I just found that Seafoam makes a product (the name of this thread) that is supposed to clean varnished fluid in the passages and fix shifting problems. I figure it is my last ditch effort before I send it out for them to either fix it or rebuild it. Has anyone used this product? 

[Bloo]

If its broken and you cant fix it without a teardown, Just bite the bullet and send it out. Chemicals to fix transmissions often do more harm than good.

 

[Bhigdog]

Yup. Fugetaboutit!........ bob

[Ben Bruce aka First Born]

Probably will do nothing. Except lighten your wallet. Though at this point not much too lose. Try it and then we will all know.

 

  Ben

[JACK M]

I say try it,

[m-mman]

I am in the same boat.

I have a 59 Lincoln that sat for 25+ years as a stalled project.  Now up and running the trans initially worked fine. Then it shuttered and banged going into drive. I drained all the fluid, sealed the leaks and added some Lucas trans conditioner. 

It now goes into reverse quickly and easily, but wont hit drive until it warms up. (about 15 minutes) After that it shifts great. 

SOMETHING is not right inside. Varnish? crud?  who knows.  

 

Yeah I MIGHT have to pull it and rebuild it, but until then . . . ?

Hey the additive only cost $8, what do I have to lose? I am driving it, hoping something breaks loose and it functions while cold. 

 

My vote - give it a try. The worst that can happen is that you are going to have to rebuild it anyway.

[cahartley]

I have experienced what Sea Foam in gasoline can do.

Give it shot.......if it does the trick it was REAL cheap fix....... ?
At a minimum it should clean up the internals in case it does have to come apart.

[Fleetwood Meadow]

I’m pretty sure that when I put a replacement part on the transmission from a parts car it had dirt or something in it and when the fluid pressure came through the part it pushed the obstruction into the transmission. My hopes is that the sea foam will dissolve the obstruction and it will run like it did before I replaced the broken part. 

[Fleetwood Meadow]

Ok, day one of the sea foam.. I put the pint into the transmission like it said and started the car. Before today I couldn’t get it to shift out of first gear. I had one day where it went to second but after that it wouldn’t shift again. So today I pulled the car out and stopped in front of the garage, put it in reverse and backed up a little then shifted through the positions in the transmission. After about 2 minutes I moved the car, mainly because I was bored and because it’s a little loud without the right exhaust on it and I didn’t want the neighbors whining. It immediately shifted into second. Online it said to drive it about 30 miles. Today I put on about 10. It wouldn’t get higher than second gear. I don’t know if the sea foam cleaned it enough to get it to second or if it was a coincidence. My cousin and his girlfriend came over later on in the day so I took them and the wife out to show them it shift. It wouldn’t shift out of first. Then after about 2 miles of it revving it clunked into second. After that it kept shifting into second. So I’d say my results are inconclusive as of day one. 

[Fleetwood Meadow]

So the weather wasn't great the past week, be it raining or super heat so I didn't ride around. Hydro-lectric windows make it so all the windows are down, can't drive around in the rain. i had added a second bottle of Sea Foam to see if that would help increase the cleaning power before I finished the first day of testing. The second day proved no better, with the exception that it shifted to second every time without problem. I can not get it into third gear though.

[dictator27]

Give it time to work.  My brother-in-law has a Chevy Venture which developed a hard shift condition ten years ago.  He was advised to put two cans of Seafoam in and drive it for three months.

  If it still had the hard shift at the end of that time it needed an overhaul.  It took three weeks.  The shifting smoothed out.  It has stayed that way for ten years until recently.  It now has an occasional hard shift so two more cans of Seafoam have gone in.  

[Franklin31]

HAVE USED THIS PRODUCT AND IT IS GREAT. USED ON 1953 Hudson 4speed AND 1997 Ford F150.  Corrected shifts on Hudson and fixed slipping on truck.

But I suppose varnish must be the ptobkem. I leave 1/3 of can in the transmissions.

[Fleetwood Meadow]

My problem is not hard shifting. I wish it was because I would be confident in the fact that it was shifting. The issue is that I had to replace the valve body in the transmission and it doesn’t shift now. I’ve cleaned it but I think debris is stuck in the block of the transmission. It has gotten better in the fact that it now shifts 1-2 every time. But 2-3 is a different valve and I don’t know if it is going to ever shift. The constant revvingis overheating my engine so I’m weary about continuing to run it like it is. I don’t want to damage my engine. The heatwave has finally broken so I am going to try it again tomorrow. I’m hoping that with the fluid sitting for a couple days it has eaten through the blockage, assuming it is a blockage. Before the second day of testing I adjusted the bands also. 

[Fleetwood Meadow]

I got a call today that the Cadillac is shifting through all 4 gears and is ready to be picked up. Luckily for me, Hurricane Michael is going to dump 4 days of rain on us. With a car that has no way to raise the windows it means the car is likely to be stuck at the mechanic’s until Monday or Tuesday. I will then attempt to drive it home the 20 minutes. I’ve never taken it for a ride that long. My only fear is overheating. I didn’t really get much of a chance to test things out for very long before I sent it out to get the transmission fixed. 

As for the transmission, the valve body was the problem. After he fixed what he thought was the problem, which was the reversed piston and missing spring, it still didn’t work. He new someone with a properly functioning valve body and put it on. It immediately shifted 1-4. Then he adjusted the T.V. Rod and road tested it several times.

[cahartley]

Thanks for posting with the solution.

Many don't which is not helpful to anyone....... 

[Dan Griffin]

Was the oil clean and pink or was ti brown? The old hydros did not use rubber O rings like later transmissions they used rings ,think tiny piston rings. Mouse milk swells up the rubber seals in latter transmissions but ti will not do much in a hydro.

[Fleetwood Meadow]

The fluid stayed nice and red throughout the whole experiment. The mechanic said he didn’t change the fluid, he just replaced what he drained when he was working on the transmission. It still gets hung up on shifting to third when you first start it but once it shifts through all of the gears that first time it shifts normally for the rest of the drive. 

[m-mman]

To add to the concluding stories, my 59 Lincoln transmission needed a complete rebuild.

The rebuilder said all the rubber rings & seals were as hard as metal and had to be picked and scraped out. It all works fine now. 

 

So related to the original thread, the additive MIGHT work, BUT . . . the trans in question needs to have rubber internal seals that are still able to be softened up and it wont fix missing springs or incorrectly installed valves.