Check your speedo mph and GPS mph. What is the difference?
With the low profile tires your speedo will read higher than actual GPS speed. YOu need to correct the speedo gear to get within 1-3% difference. Only then will your trans shift come close to functioning correctly.
You need a different speedo gear. Probably 2 numbers bigger.

 

Speedo indicates 5 or 6 mph faster than actual speed.

 

There you go. You need to get a gear that brings that to within +/-1mph at 60mph. It can be a little trial and error on the correct speedo gear needed to correct this.

 

How would the jeep know that though? It can't tell how tall the tires are. I can't think of how tire height could affect anything other than the speedo reading a percentage higher.

 

I asked the same questions when my friend told me this. Finally after having the two tranny codes come up every 6 months I went ahead and got the correct speedo gear. After doing that, no more codes for the tranny. That's been over a year now.

Not sure how it works but it does.

 

hmmmm, alright. It's got 26 inch tires on it now but i plan to go to a 28" so ill leave it alone for now. I took a video last night. You can see what its doing on the 1-2 shift in it.

 

Jeep ran 9.69 at 71.5mph in the 1/8th. Gonna use a rotary switch to manually shift the trans to see if that helps. Need to weld wideband bung on too. Really want to do a 2.5 inch front exhaust pipe but can't find one. Probably needs to be custom i guess.

 

The supercharger kit is for sale. If anyone is interested pm me.

 

what happed to the jeep?

 

Nothing. I'm going to do a 5.3 or 6.0 ls turbo swap

 

do you still have the jeep? still planning LS? your rev issue is definitely trans and TCM related, but I dont want to get too much farther into it if the jeep is gone, or motor is pulled.

 

Yep I still have. The motor and supercharger are long gone though. Currently building the motor and getting the engine bay ready for paint. Thanks for offering your help though.