Matt129 Posted July 27, 2023 Share Posted July 27, 2023 Hello, I’m looking into getting an 1960 AMC rambler cross country that’s in great condition, but the only thing wrong with it is that it won’t shift gears until the engine is revving higher than it should. The owner says that it just needs a Vacuum Modulator solenoid replaced on the flashomatic transmission, and it will be fine. How hard is it to replace this part and where would I even go about finding one? I’ve done some searching online and I can’t seem to find one although it seems like a common issue. Should I pass on this rambler because of this issue? I don’t have experience with the flashomatic so I wouldn’t know lol. Thank you for any help you can give me. Link to comment Share on other sites More sharing options...
TerryB Posted July 27, 2023 Share Posted July 27, 2023 On more modern cars the modulator screws into the side of the automatic transmission. I would guess the same may be true for this car. There is a vacuum line from the engine that gets connected to the modulator. 1 Link to comment Share on other sites More sharing options...
TerryB Posted July 27, 2023 Share Posted July 27, 2023 Check with a transmission parts supplier called Fatsco. They have a website. 2 Link to comment Share on other sites More sharing options...
rocketraider Posted July 27, 2023 Share Posted July 27, 2023 Flash-o-Matic was AMC's trade name for the Borg-Warner M8 three-speed torque converter automatic. Other carmakers also used the M8 so shouldn't be difficult to find a vacuum modulator. You might have to go thru sources other than your local auto parts store. Try Fatsco, Northwest Transmission or Edwards Transmission. All those specialize in older transmissions. As Terry has pointed out, check the vacuum modulator's vacuum source line from engine to modulator. If it's kinked or loose the modulator won't function and the transmission will only upshift when its governor forces it to. Since it does eventually upshift, that tells me the transmission is functioning. 2 Link to comment Share on other sites More sharing options...
joe_padavano Posted July 27, 2023 Share Posted July 27, 2023 X2 on Fatsco. 1 Link to comment Share on other sites More sharing options...
Matt129 Posted July 27, 2023 Author Share Posted July 27, 2023 19 minutes ago, joe_padavano said: X2 on Fatsco. Can you post a link? I’m probably just dumb but I looked on there and I couldn’t find it 😂 Link to comment Share on other sites More sharing options...
TerryB Posted July 27, 2023 Share Posted July 27, 2023 (edited) https://www.fatsco.net/ Never hurts to call them for the part even if it’s not listed. Edited July 27, 2023 by TerryB (see edit history) 1 Link to comment Share on other sites More sharing options...
joe_padavano Posted July 27, 2023 Share Posted July 27, 2023 1 hour ago, Matt129 said: Can you post a link? I’m probably just dumb but I looked on there and I couldn’t find it 😂 Not everything is shown in their online catalog. Open their PDF catalog and you see this. 1 1 Link to comment Share on other sites More sharing options...
Oldtech Posted July 28, 2023 Share Posted July 28, 2023 Easy to change from under the car. Common problem with these, at least was 40 years ago. 🙂 1 Link to comment Share on other sites More sharing options...
Bloo Posted July 28, 2023 Share Posted July 28, 2023 (edited) Be sure there's vacuum to it and the hose isn't leaking. In addition to the shift problem, bad ones usually feed a bunch of transmission fluid to the engine and it makes a bunch of white smoke out the exhaust. I can't help but wonder if the hose on yours is disconnected or damaged. This one seems to have an electrical solenoid implemented. I'm not sure why that is. Since there is a repair kit listed in @joe_padavano's link, it may be rebuildable. That is probably the best option if so. A bad modulator was never considered a big deal to fix back in the day, and it probably isn't a big deal now. They do generally need adjustment after replacement. On newer modulators, the adjustment is a screw up inside the vacuum fitting. I'm not sure how that one in the picture adjusts. You'll probably have to have the service manual to figure that out. What you are adjusting is the part throttle upshift speeds (miles per hour). There will be specs in the manual. Edited July 28, 2023 by Bloo (see edit history) 3 Link to comment Share on other sites More sharing options...
TerryB Posted July 28, 2023 Share Posted July 28, 2023 My 1961 Motors manual has the instructions for setting the operation of the modulator. 2 Link to comment Share on other sites More sharing options...
c49er Posted July 29, 2023 Share Posted July 29, 2023 Some sellers are so lazy. He says all it needs....a modulator and so easy to install...if true he should do it to make an easy quick sale. Jeez lazy sellers! 2 Link to comment Share on other sites More sharing options...
Matt129 Posted August 5, 2023 Author Share Posted August 5, 2023 On 7/28/2023 at 10:37 PM, c49er said: Some sellers are so lazy. He says all it needs....a modulator and so easy to install...if true he should do it to make an easy quick sale. Jeez lazy sellers! His excuse was that he didn’t want to put any money into a car he was getting rid of lol, but the more he tells me about the car sounds more and more like the modulator might be fine and he just doesn’t know what it’s supposed to be like😂. He says that it feels like it shifts out of 1st into 2nd at about 10-15mph and then stays in 2nd gear until it gets to like 50-55mph and then it will shift into 3rd. He says it seems to like higher RPM to shift. Is this normal for one of these? Link to comment Share on other sites More sharing options...
Littlestown Mike Posted August 5, 2023 Share Posted August 5, 2023 "He says that it feels like it shifts out of 1st into 2nd at about 10-15mph and then stays in 2nd gear until it gets to like 50-55mph and then it will shift into 3rd. He says it seems to like higher RPM to shift. Is this normal for one of these? " This line alarms me. " He says" Have you driven it? Never accept a seller's description. Never buy a car that the seller won't let you drive. The seller may be able to control how the car feels because he knows more than you. You sitting on the passenger side would never suspect the driver may is able to mask all kinds of issues. Now, if this is a long distance buying opportunity, then my criticism is not valid. Replacing a vacuum modulator is an easy task--so easy one wonder why the seller doesn't do it. \Lots of discussion on the AMC forums. 60 year old rubber diaphrams tend to crack and leak. NOS may not be much better since rubber deteriorates with age. 4 Link to comment Share on other sites More sharing options...
c49er Posted August 5, 2023 Share Posted August 5, 2023 I don't think the seller really knows how to fix the problem...just another car he needs to get the most cash out and with the least effort and repair cost. 1 Link to comment Share on other sites More sharing options...
rocketraider Posted August 5, 2023 Share Posted August 5, 2023 After thinking about it a minute...🤔 In seller's defense, he may have no idea how to replace or adjust the modulator. Yes, there ARE people who like to own old cars, and to be seen driving old cars, but who have no idea how to do anything more than wash them and vacuum the interior. Then there's the matter of finding someone who can and is willing to make the repair. Around 2004, I needed some transmission work done on a 1976 Turbo HydraMatic 400. With four transmission shops in this area I had a hell of a time finding somebody who knew anything about them. THM400 had been out of production 18 years at that time and all anybody knew about were electronic and computer-controlled transmissions. 20 years later I'm sure it's worse. Link to comment Share on other sites More sharing options...
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