1988 Dodge Ram b250 van, 5.2 engine.

It won't upshift into the highest gear unless I let off the gas a bit or get the revs up way high. I have not checked fluid levels or anything.

Help!

 

We do not know if you have just a 3 speed transmission and the 2-3 shift is the issue, or a 4 speed overdrive transmission with a lock up torque converter, and Overdrive is not engaging, or if the lock up is not engaging.

All are different problems with different causes and solutions.

Do you have an OD off button?

If you do, Have you done the 'Key dance' and seen if you have a code 15 for the vehicle speed sensor?

 

No OD off button. I'm guessing its a 3 speed, cuz that's what it feels like.

 

You'll have to wait for somebody more knowledgeable to respond but I think a pan drop filter change and band adjustment would help if not solve the issue

Use only ATF+4, nothing else to refill

 

"Pan Drop", is that the engine oil pan, or transmission pan? I've never touched a transmission in my life! I'm looking forward to youtubing it to learn though.

 

Sounds like the governor valve inside the tranny is cracked and leaking. If you don't know transmission very well then this is a tranny shop job.

 

If the governor valve is contained within the valve body I would say he could change the entire valve body easily enough without having specific knowledge about transmissions.

 

I was thinking more that the pressure had to be tested to confirm an issue with the governor rather than just throwing parts at it.

 

Yeah that is definitely the proper and professional line of thinking. But if you plan to drop the pan to change the fluid and gasket anyway it might be worth changing out the valve body. My local U-Pull yard only charges $20 for one so in my case it would be worth a try.