So I have searched several different posts about this topic and tried various things but continue to have issues. I live 2 miles from work. When i drive it to work it shifts perfectly as it should, after 2-3 hours at work and I head home for lunch, most times, it will not shift properly until I tac it to at least 3500 to shift. Once it has done that it shifts properly as it should and doesn't do it again unless I let it set for an 1-3 hours. Anything less that an hour or more than 4 it shifts as it should and I don't have any issues at all. I bought it a year ago and have had this issue since the beginning, not realizing how far down the rabbit hole I would go. I currently live in Hawaii, so parts and donor vehicles are far and few between. I've replaced the TPS, Solenoids, Torque Converter and flushed and replaced the filter twice. Based on the symptoms I'm stumped on what the actual problem could be. Any help would be greatly appreciated.

 

try this:CRUISER'S MOSTLY RENIX TIPS

TRANSMISSION CONNECTOR REFRESHING

OCTOBER 30, 2015 SALAD 22 COMMENTS



Over near the transmission dipstick tube are 2 rather large connectors. One is black and goes to the NSS and the gray connector goes to the transmission itself
. These 2 connectors carry all the info between TPS, TCU, NSS, speed sensor, and transmission solenoids.

Unplug each one, visually inspect for corrosion or bent pins, spray them out with electrical contact cleaner and plug them back in.

Additionally, if your Jeep is an ’87 to ’90 Renix, it’s always a good idea to reach up under the glovebox area and unplug the connector to the TCU and spray it out along with the receptacle of the TCU. While you’re there, find the fuse right in that area for the TCU. Remove it and spray out it’s receptacle and clean any corrosion from the fuse.

 

If you have replaced the torque converter already in an attempt to fix this issue I would say you have already gone too far down the rabbit hole
I don't know what you mean by "it will not shift properly until I tac it to at least 3500 to shift."
Do you let the vehicle warm up for several minutes? In a 2 mile drive things wouldnt be getting very warm so I am assuming this is an issue only when the engine and trans are at least warm. Am I understanding that right?
If the vehicle is cold if shifts fine but when you drive it after its warm it gives you trouble?

 

Not shifting meaning won't shift out of 1st? Have you adjusted the cable from the throttle body?

 

I had this issue. I have resolved it, twice.

1st time: I replaced the TPS, TCU, solenoids, adjusted the kickdown cable, etc etc. I ended up figuring out that I had a TPS issue after replacing the TPS. Parts store sensors are bad about that. They'll read good when bench tested, but they're really not. Try swinging by a U-pull-it and grab a handful of OEM Mopar TPS. They're cheap, and better than anything aftermarket.

2nd time: I replaced the whole transmission with an AX-15. Now it shifts just fine!
(Mostly kidding. I didn't swap it because of the TPS)

 

 

It shifts fine as long as it's cold, when it warms up and sets for an hour or longer it acts as though it's in 3-4 gear and stays there until I get the RPMs to 3500. It's an intermittent issue that has many variables but none make sense to me as to what the problem could be.

 

It will go into a higher gear like 3-4 and stay until I get it around 3500 RPMs. After that it will shift properly until I start the cycle all over again. i've adjusted the cable several times in an attempt to resolve this.

 

How about the Tip I posted?
what fluid are you using?

 

The first thing I did was the Bleepin' Jeep video, I checked the connectors and sprayed them before replacing the solenoids and torque converter. It kind of seems like it's internal to the transmission based on the fact it does fine at first then once it's warmed up it act crazy if I let it cool off for a certain amount of time. It doesn't do it every time either, sometimes if i let it idle 1-2 minutes before trying to drive away it shifts as it should. I flushed the transmission using Transmax Dex/Merc.

 

Just a theory to put into a more knowledgeable head on the AW4 but could it be a fluid drain-back related issue? Like a one way valve is failing/has failed and within the specified timeframes it causes issues? Maybe foaming of the ATF, or foaming of the owner trying to figure this issue out?

 

That's what I'm wondering. Is it an internal issue from a check valve or something like that. The jeep has 238k on it and doesn't appear the engine or trans have ever been rebuilt. With my current location reputable shops are far and few, getting a replacement trans is extremely costly due to shipping.