97 Ram 1500 delayed 2-3 shift when hot

I just bought a neglected truck. When I first got the truck, it would not shift out of 1st. The tranny was 2 qts low and the pan was covered in mud. I cleaned the tranny and changed the filter and added about 5 qts of ATF+3. Now the tranny started to shift and after a while it started shifting to all gears. Now it shifts great almost perfect until about 15-20minutes when the tranny is warmed up, then it shifts later to 2nd and I have to let off of the gas to get it to shift to 3rd. Once it shifts to 3rd the overdrive shift is fine.

Should I go to Jiffy Lube and do a full fluid exchange 18qts? The fluid and sludge I got out with just the filter and 5qts was pretty bad. It was really slimy and sludge like.

Should I take it to a transmission shop for diagnosis?

Since it shifts great when its cold after the filter and small amount of fluid change, I'm thinking that the tranny was serviced with crappy fluid before I got it, and when it gets hot the fluid doesn't perform well. The local tranny guy says that would not cause my problems. Is he right?

What should I do?

Thanks
Chris

Also I just got check engine light and the code is 37. is that the solenoid or the tranny temp sensor for 97'. If so, what should I do.

Chris

This could be a code indicating the delayed upshift to which you referred. It could be a code indicating the solenoid is defective, but that would eliminate the shift entirely. My suspicion is that the delayed upshift is setting the code. I would have the trans serviced, convertor and all, then service it again within two months, or 5,000 miles. This could be a varnish issue. Ray

Thanks for the advice.

Amco said not to change the fluid, that it would make it worse. I followed RABarrett's advice and also added some transmission varnish remover. Then I changed the filter and also disconnected the cooler return line and did a full fluid exchange. The transmission works perfect now. But about 2 miles down the road the check engine light came back on and I did the ignition check and the codes were 12, 37, 55. I'm going to stop by my friends shop and read the codes with his computer. Thanks again

Chris

Chris

Hopefully it is not to late. I am having the same problem you had with your tranny except my check engine light does not come on. After a while during warmup my tranny does not want to get into 3rd without letting off the gas a bit. please help me out

Ryan

Ryan
Well the tranny is still fine after I did a full flush. First I ran some varnish remover through the tranny from napa, then disconnected the cooler return line and pumped out about 4qts at a time by running the truck and putting it in neutral, it comes out very quickly, then I added the 4qts. I did this until the fluid was pink and ended up with about 14qts or so. If you need some more details let me know.

Chris

Chris

Wow a whole lot in my investigating have I found. First thing is their was a problem with the transmission in the manufacturing process. According to the Transtechnical Bulletin they state that some problems are in the Direct clutch inner seal may have been machined incorrectly from the factory. This allows the original seal to slide into the casing and create a problem with the delay in revers, slipping 2-3, and no 2-3 complaints that have been reported. These reports do not show up in any of Dodges bulletins as they claim. According to this particular bulletin from Transtechnical the original molded lip seal from the 518 transmissions are .130" on the 89 models and up. The updated seal calls for a .170" seal made of viton to resist wear and heat deterioration like the original seal has done.

In learning even more from several mechanics around the state this is an ongoing issue with the dodge products. Although according to these mechanics, YES the change or flush does seem to prolong the problem, but does not solve this issue. I was informed that prolonging this problem can lead to greater problems in the future, thus costing 2k or better in replacing the transmission. They call it a temporary fix to get rid of the vehicle. Hopefully this info is helpful if you find out any more info yourself. This is not by any means a solve to the problem, but info I figured I would share. Hopefully Dodge Corp figures a problem and is willing to fix the problem. Thank you for sharing info and hope this can be helpful as well.