I noticed this problem with my wife’s car over the past few days. It seems like the automatic gear is not catching at the speed it is supposed to, so the engine runs high until it “catches up”. For example, I would expect a shift around 40-45 mph, however, the engine runs hard up until 55mph, where the gear finally catches. If I slow down, it runs in that gear until it gets down to 45mph, where you will hear feel the transmission adjust downward, but the engine is still running high (RPM-wise). The car is a 1988 Plymouth Reliant with about 107,000 miles. I thought the car was a 4-speed auto transmission, and it seemed as if the 3rd gear was just not catching at all, but according to this, it seems the car only has 3 speeds to begin with. I can definitely feel the three gears, from 1st to 2nd at around 25-30 mph (the RPM rate seems a tad high at that shift), and the 2nd to 3rd at 55 mph (with the problem as above). I plan on asking a friend tonight his opinion, and plan on taking it to the shop later this week as this can’t be normal, but any opinions will be most welcomed.
How long has it been since the tranny was properly serviced? Not just changing the fluid and screen but adjusting the bands? With any luck that may be all it needs.
Can’t say that I know, we bought it about 6 years ago at 70,000 miles, and changed the fluid at least once. We take it in at least once a year for a wintertime full inspection/tune-up, so I’m not sure if it has been “serviced”.
I’ve always been avised not to go to a transmission shop but it you need a rebuild you need a rebuilt. Ask aound for a reputable shop to use. Have it diagnosed and serviced properly and see where you are after that.
a) Can the bands be tightened?
b) Can the bands be tightened by warming up the car in my driveway and, with foot on the brake, slowly run through each gear? Does this help at all?
At least, in the past before I was driving, they claimed this worked…did it? And, does it now? - Jinx
IIRC, the last MoPaR transmission with adjustable bands was the A727 Torqueflite. None of the FWD transaxles have adjustable bands. Assuming that the fluid is correct, and that it isn’t burnt, the pickup filter/screen is clean, and the level is good, I’m suspecting from the symptoms described that the lock-up torque converter isn’t engaging.
You may know all this, but just in case…When you check the fluid level, the car should be warmed up and running (as well as the obvious on a flat surface). The fluid should be red, no brown in it. Too much fluid is just as problematic as too little. The problem with transmissions is that there are so many internal parts, it’s really hard to make a call on what’s wrong. There are websites that will help narrow down some possibilities based on symptoms, but not a whole lot you can do without taking apart the tranny. Then, of course, you’re at the mercy of the mechanic. Have you looked into all of the other possibilities? Plugs and wires, fuel pump, timing, that sort of thing? I had to have a new (rebuilt) transmission put in a couple of months after I bought my most recent (used) car. I shopped around, got recommendations and then the dealer I bought it from had it done somewhere for 1200 dollars, which was cheap compared to the quotes I’d gotten - anywhere form 1500-2000. So far, so good, but it really sucked having to put the money out so soon after I bought the car. At least the dealer gave me a “rental” while it was being done. And a marriage proposal. Neither one really took the sting out, though.
Update…I drove it again this morning, and I did not notice the problem at all, except possibly near the end of my inbound to work journey; a stark contrast from yesterday. Still plan on taking it in this week though.
I’m betting your normal shifting behavior is probably like this: when you accelerate hard, the engine revs way up before it shifts, hard, at a high road speed. But if you accelerate lightly, it shifts much more smoothly, at a low RPM and road speed. The automatic transmission takes input from the throttle in order to accomplish this behavior.
Your transmission is most likely connected to your throttle, either directly, through a springloaded steel cable, or via an electronic sensing device (called a throttle position sensor or something similar). If it’s a cable, it could have broken, become disconnected, or gotten stuck. These cables work such that when you press down on the accelerator, the throttle pulls on the cable, and when you release the accelerator, spring tension allows the cable to retract again. If the cable got stuck and didn’t retract, then the transmission might think you’re pressing the gas much harder than you actually are, and consequently it would rev higher before shifting. Much the same effect could occur if something has gotten broken or corroded in an electrical throttle position sensor. These sensors are simply variable resistors, and a little bit of dirt or rust, or a loose connection, could confuse your transmission or its control unit.
Either scenario is a possibility on an '88 in light of the age alone. Moreover, in light of the fact that your transmission spontaneously started working normally again, it seems like an easy explanation would be that what was stuck simply became unstuck again, or a loose electrical connection jiggled itself back into place. In any case it’s worth checking - it’ll be a lot cheaper than a rebuild if it is in fact the culprit.