Mercomatic no shift (all nuetral) All help tremendously appreciated

[Noodlecare]

Hello everyone . I’m new to this forum so if I accidentally mess up sorry I’m advance . I bought my 55 mercury Monterey after it was sitting for 25 years. Got it running did fluids . I took it for one test drive and I cut it short due to my radiator having a leak . I took it home and parked . Two weeks later do the water pump and radiator ,excited for my test drive , I shift it from nuetral to drive nothing . Neutral to park and I get nothing . Same with reverse.

I checked the linkage it’s all hooked up and it’s moving at the trans . The throttle position pressure linkage to trans is also hooked up . No noise or anything off . Just all gears are neutral. I checked fluid with it running and it is where it needs to me . Can the mercomatic tranny just go bad like that ? Nothing changed . I jacked up the rear axle and the driveshaft wasn’t spinning with the motor . And I confirmed all the shift positions are neutra (I can spin rear wheels easy ) I’m really stumped . All help is greatly appreciated

[KULTULZ]

How did the trans operate @ the first test drive?

[Noodlecare]

It was completely normal . Fluid level maintained . No noise or vibrations. Shifted fine .

[Noodlecare]

Originally Posted by KULTULZ

How did the trans operate @ the first test drive?

I accidentally forgot to quote you in my response . But it was completely normal . Shifted fine . Fluid level maintained . No noise or vibrations . And shifter linkage operated same as it does now I believe .

[KULTULZ]

If you changed the fluid and filter, it may be the new fluid ate away the varnish deposits in the trans.

There will be a complete trans diagnosis procedure in the period A/T REPAIR MANUAL.

[Noodlecare]

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Originally Posted by KULTULZ

If you changed the fluid and filter, it may be the new fluid ate away the varnish deposits in the trans.

There will be a complete trans diagnosis procedure in the period A/T REPAIR MANUAL.

The only fluid I didn’t change was trans . It was to level when running and was clean and didn’t smell burnt at all. It was also red like atf should be . I changed diff oil and engine oil . Where do I find a/t diagnosis section ? Thank you

[Noodlecare]

Another update. Today started the car . And had gears again. Park reverse neutral and drive and low. I drive it 50 ft and flip around and let it idle in the driveway. I hop back in it after 5 mins of idle and lost gears 😳. Same as yesterday . Just stuck in neutral . Shifter on trans still moves but nothing .

[dmsfrr]

Originally Posted by Noodlecare

... Where do I find a/t diagnosis section ? Thank you

The automatic transmissions have their own Service Manual, not part of the usual vehicle Service Manual.

There are currently a couple on ebay that 'could' be what you need.
Not sure, I'm not familiar with them at all.

https://www.ebay.com/itm/13450677493...YAAOSwcntcxFyU

https://www.ebay.com/itm/19559636083...0AAOSwz0Nj6dHT

[Merc Cruzer]

From the book, hope it helps.

Make the throttle control rod longer, to make it shift harder and shorter to make it shift softer.

[cadillac512]

Maybe you've found the reason it was sitting for 25 years? Seriously though, it sounds like it could be a sticking pressure regulator valve or a pump suction problem (filter/screen?). May even be a sticky valve in the valve body, so the more you drive it (when it will go) the better it may behave. Better stay close to home though....


Terry

[rjlester]

I'm also in the camp of, drive it more and it will get better. As stated by cadillac512 the more you drive it the better it will get. Probably a sticky valve in the valve body and with use/heat it should loosen up.

[Alaska Jim]

My guess would be that the shift selector valve is sticking, since you did not change the fluid. Changing the fluid could fix it, BUT, it could also make it worse, as the new fluid will have "detergents" that will help clean any varnish off the internal parts. you might try a Transmisson conditioner additive. it may cure your problem

[Merc Cruzer]

If all else fails, you could try this (or something like this), before you change the fluid. If it is sticking, because it is all gummed up, it might clean it up enough to make the transmission work again. If it does work, then you can change the fluid and filter:

https://www.ebay.com/itm/14497853933...289d4dc0983d08

[50fordcoupeman]

Originally Posted by Merc Cruzer

If all else fails, you could try this (or something like this), before you change the fluid. If it is sticking, because it is all gummed up, it might clean it up enough to make the transmission work again. If it does work, then you can change the fluid and filter:

https://www.ebay.com/itm/14497853933...289d4dc0983d08

Good advice!! My transmission guy said to run a bottle of similar cleaner thru BEFORE I change the filter and fluid.

[rotorwrench]

They run off pressure so the pumps have to give good flow and the pressure regulator has to work. The selector is connected with a valve that sounds like it was functioning normally at least when the car actually had band actuators and clutch pistons working. My guess it that it has an internal leak somewhere that's causing a loss in pressure. There are a number of tubes in there than can leak. The oil screen may be gunked up too.

Do you know what type of fluid it in the transmission? I ask this because the fluid that was used in 1955 is no longer available today. What ever is put in it in the future should be the same as what has been in it all these years.

[Noodlecare]

Originally Posted by cadillac512

Maybe you've found the reason it was sitting for 25 years? Seriously though, it sounds like it could be a sticking pressure regulator valve or a pump suction problem (filter/screen?). May even be a sticky valve in the valve body, so the more you drive it (when it will go) the better it may behave. Better stay close to home though....


Terry

That’s a good point . Thank you . It started to hit me maybe that’s the reason. Everything on the car mechanically besides trans was in decent shape. All bolts were easy to brake lose , spark plugs , wiring , etc. so it looked like somebody took care of it and then just stopped .

[Noodlecare]

Originally Posted by rotorwrench

They run off pressure so the pumps have to give good flow and the pressure regulator has to work. The selector is connected with a valve that sounds like it was functioning normally at least when the car actually had band actuators and clutch pistons working. My guess it that it has an internal leak somewhere that's causing a loss in pressure. There are a number of tubes in there than can leak. The oil screen may be gunked up too.

Do you know what type of fluid it in the transmission? I ask this because the fluid that was used in 1955 is no longer available today. What ever is put in it in the future should be the same as what has been in it all these years.

You are correct. I haven’t opened it up because I don’t have the experience , but that’s exactly how it acts . Eepecially cuz I disconnected the linkage and shifted it by hand . Is this something you think I possibly can diagnose by opening tranny pan while still on car or do I need to pull it out completely

[Merc Cruzer]

Basically, we have the same transmissions. Mine is in a 53' Merc. I changed mine last year, to include a new screen and gasket and draining the torque converter. Mine works great. Your screen and gasket may be different.

NAPA Type F, may be a bit hard to find, but if you call a coupe of stores, your should be able to get enough for the change. It took two stores for me to get what I needed. The screen and gasket, I had to get on line.

[miker98038]

I’m not much of an auto guy, at least for the last few years. But I’ve seen numerous references to a Lucas product guys have had good luck with. Cheap and easy to try.

https://www.amazon.com/Lucas-Oil-Tra...35946796&psc=1

Clean oil, no miles, intermittent. Sounds like maybe why it was parked. I’d try the “rebuild in a bottle” first, but I’d plan on dropping the pan and doing the service Cruzer outlined above. It’s a messy job, but worth the effort before you give up and pull a transmission. Those are heavy, use due caution and a friend.

[Merc Cruzer]

Originally Posted by miker98038

I’m not much of an auto guy, at least for the last few years. But I’ve seen numerous references to a Lucas product guys have had good luck with. Cheap and easy to try.

https://www.amazon.com/Lucas-Oil-Tra...35946796&psc=1

Clean oil, no miles, intermittent. Sounds like maybe why it was parked. I’d try the “rebuild in a bottle” first, but I’d plan on dropping the pan and doing the service Cruzer outlined above. It’s a messy job, but worth the effort before you give up and pull a transmission. Those are heavy, use due caution and a friend.

Totally agree. Go with a product, "rebuild in a bottle", first. By the way I used ramps, jack stands, and chocked the rear wheels. Can't be to careful!

Not sure is yours has it, but check to see if you have the cover plate, allot of the cars have lost them. Mine was gone when I bought the car.