Tranny Issue

[JBM]

Hey all i have a Jeep GC with the 4.0 6 in it. When everything is cold the transmission has trouble going from 2nd to 3rd. The transmission wont shift until about 3k rpms. After it warms up, everything shifts fine.

I have no idea about the maintenance on the vehicle, so my plan so far is to add 6 oz of ARX and drive it for about 1000 miles and do a fluid/ filter flush.

The Jeep has 125k on it, and i am aware there is a sensor or 2 that typically go in these transmissions, but im not sure if this is a sensor issue or a mechanical one?

Opinions, i know nothing about transmissions ?

 

[aquariuscsm]

My old 300ZX turbo was the same way. It wouldn`t go into overdrive until the engine was at a certain temp. Look at an FSM to make sure it`s not normal in your car. In mine it was.

 

[ionbeam22]

Leave it alone, ATF+4 only.

 

[Kestas]

What does the fluid look like?

 

[Trav]

There are some issues with sensors and solenoids,one of the guys here has the same jeep with the same engine/trans and had the same problem.
It was something to do with the Governor pressure,i will ask him on wed when i see him exactly what he did, i remember he changed two components out and it worked like it should.

All the additives in the world isn't going to help if its a component failure.

 

[JBM]

Ahh thanks guys. Ionbeam, are you saying not to add the ARX to the transmission?

 

[SteveSRT8]

additives may only compound the issue. They don't fix broken parts.

 

[PT1]

You could have:
1. dirty or malfunctioning solenoid
2. " " " " speed sensor
3. ECM issue not sending correct data
4. bad alternator= low voltage to ECM=bad data
5. weak battery= all of #4
6. poor internal hydrauiics/mechanical part failure

 

[440Magnum]

Originally Posted By: JBM
Hey all i have a Jeep GC with the 4.0 6 in it. When everything is cold the transmission has trouble going from 2nd to 3rd. The transmission wont shift until about 3k rpms. After it warms up, everything shifts fine.

I have no idea about the maintenance on the vehicle, so my plan so far is to add 6 oz of ARX and drive it for about 1000 miles and do a fluid/ filter flush.

The Jeep has 125k on it, and i am aware there is a sensor or 2 that typically go in these transmissions, but im not sure if this is a sensor issue or a mechanical one?

Opinions, i know nothing about transmissions ?


I wouldn't put ARX (or any other solvent) in anything unless you promised me a free Challenger SRT-8 to do it. Especially not in an electronic transmission.

Most, if not all, Jeep 4.0s are backed up by the Aisin-Warner AW4 automatic, which is NOT a Chrysler transmission. First off make sure which transmission you have... but its probably an AW-4.


If so, its most closely related to transmissions used in rear-drive Toyotas. Its pretty stout, doesn't need ATF+4 (although it works fine with it), but it does have all the usual electronic transmission wierdness. It could be an output speed sensor, or it could be an internal problem. Since it happens cold and not warm, I doubt its a failing clutch pack or mechanical problem that's usually the other way around- works cold, fails when hot. It could be something as simple as a clogged filter.

I would do a simple fluid and filter change (NO FLUSHING AGENTS!!!!) and see if that helps.

 

[bustednutz]

I'm betting on a sensor issue, or solenoid issue.

 

[Colt45ws]

ARX is not a solvent. I have used it in a GM 3T40 with success.

 

[Gary Allan]

Do we even know the year here? AW4 was in the Cherokee ...don't think it was ever in the Grand.


..but something is hanging up due to visc ..which will translate to temp/pressure.

 

[JBM]

Its a 2000 Grand with the I6. I dont know what kind of transmission it is, but i will get it to the shop for a filter/ fluid change and see if that helps. Thanks guys.