2.3L ('83-'97) Decelerating while driving

[S.Wardlow]

Hello, I've been experiencing some issues while driving the past couple of days. whenever I'm up to speed on the highway the ranger will start to decelerate after maybe 10mins of driving. then it will only go about 15mph. I ended having to put it into 1st, 2nd, then drive and it would be fine. Today I waited a while for the truck to cool down and it drove fine. the oil levels are okay. the transmission fluid levels are okay, the engine runs fine.
was wondering if i could get some help or ideas as to what might be the problem thank you.
1997 ford ranger XLT 2.3L I4

 

[franklin2]

See if you can listen to it and find out more what it sounds like it's doing.

Is the engine struggling like it's under load? Or the engine starts to slow down by itself. It sounds like if you can downshift and bring it back up, that the engine is being loaded down by something. Brakes locking up? When it does it again, pull over and put your hand on each wheel, all 4 corners. See if one of them is hotter than the rest.

 

[S.Wardlow]

I would be able to smell the breaks if it were them. it will throw its self into neutral and the only way to get it to move was whenever you put it into 1st, 2nd. however now I've changed my gear lever position sensor or neutral safety switch and it fixed the problem of throwing its self into neutral but at a certain point it wont go past 2nd gear. So I'm thinking the torque converter clutch solenoid but who knows till i get it into the shop. thanks for the suggestion

 

[franklin2]

What color is the fluid on the trans dipstick? Hopefully not brown and has a burnt smell. If it's very dark burgundy, a fluid and filter change may help it. New fluid looks bright pink, good used fluid is a red color.