[1975fury]

To start my name is Jesse I just purchased my first mopar its a 1975 Plymouth fury 2 door with the 318 and 904 trans. Im having an issue with it when im accelerating its reving uncontrollably it does it about 3 times high then low high then low high then low and stops and drives normal. What is this problem and what do I need to do. Thanks ahead of time.

 

[valiant67]

I think you are describing the transmission slipping. Best case scenario is that the transmission fluid is low. It needs to be checked hot with the car idling in neutral after having been engaged in forward and reverse. Worst case, there are transmission issues. When you check the fluid level, look at the fluid on the dispstick. If it's not bright red the fluid may need changed. if the fluid smells burnt that may indicate transmission problems.

 

[TWX]

The transmission can have its bands adjusted as well, which might prolong the life of it, assuming they're worn. A reputable mechanic should be able to do that, no need to necessarily take it to a transmission shop. It will need fluid because the pan has to be removed, and if you're planning on keeping it a long time, it would be a good time to get a deep pan kit. Regardless of depth, I strongly encourage getting a pan that has a drain plug, as it makes servicing the transmission a lot cleaner and easier when one can drain it out before cracking the seal.

I like the looks of this kit from Mopar Performance via Summit Racing:

https://www.summitracing.com/parts/DCC-4007886/

That fifty dollars is well spent if you spend any time working on it. I dealt with transmissions several times before buying one and I wish that I had done it the first time I opened it.

 

[dana44]

If this problem is happening right after you start the car after sitting overnight, it is also a common issue and happens to almost all of us. There is a fluid drain that empties the torque converter when it sits and the front pump has to refill the transmission when you first start up. Later on in life they put a check valve into the pump to prevent this, but I think is was not until around 1978ish. So, if this is the case, when you first start the car, shift into drive, neutral, drive, neutral, then drive, about a second between the changes, and it pumps the fluid where it belongs and is good until next time you let her sit overnight. The other recommendations are also good, maintenance is usually pretty lax over the years, especially if you don't know the history of the vehicle.