I decided to name my 89 Jeep Grumpy. Sure acts that way. Got 188050 miles. Transmission was shifting fine. Only once did I think I felt it slip going into OD. When I say overdrive, I mean the D has a circle around it. Is that common? There’s no button to manually turn OD on or off. When I shift down to 1-2, I feel it downshift. Any thoughts?

 

Sine it is an electric controlled transmission, I would start with this...

https://cruiser54.com/?p=58

 

As it happens, I bought a TPS and never installed it since it wasn’t the problem. I just installed it and now it shifts. You and others I have talked to all recommended the TPU, so I ordered one to keep handy. Thanks for the reply!!
Now I have to figure out all the adjustments to make sure it’s shifting right. Grumpy wants to downshift when you let off the gas. And it seems to be idling a little too fast.

 

You must complete Tips 1,3,4,5 and 10 at www.cruiser54.com before anything else.

Then, adjust the TPS and throttle valve cable.

 

Thank you!! I’ll admit that I’m gonna have to get someone to help me out with some of those. But I’ll let you know how it turned out.

 

Ive found cleaning the butterfly on the throttle body helps too. If it can't shut all the way it will throw off the TPS and hence the shift points. Any mill with 100k or more will get the carbon circle around where the butterfly closes. MAF cleaner and toothbrush.