Cherokee XJ - Hard shift auto when cold?

[Mike1]

Hi All

I have a 98 XJ, recently it has started to shift hard up through the gears on initial start up when cold. Once the vehicle heats up then the shifting becomes normal again. I have checked the transmission oil and it is at the correct level with engine running in park, the oil is the correct spec. as per the user manual, and the service on the tranny was done around 4000 miles back? I only use the vehicle once a week on weekends, so it stands most of the time, what other obvious faults could there be, possibly a pump of some sorts needs to be replaced or should I do an oil change and service again, possibly something is blocked?

Regards

Mike

[Dry suit diver]

Originally Posted by Mike1

Hi All

I have a 98 XJ, recently it has started to shift hard up through the gears on initial start up when cold. Once the vehicle heats up then the shifting becomes normal again. I have checked the transmission oil and it is at the correct level with engine running in park, the oil is the correct spec. as per the user manual, and the service on the tranny was done around 4000 miles back? I only use the vehicle once a week on weekends, so it stands most of the time, what other obvious faults could there be, possibly a pump of some sorts needs to be replaced or should I do an oil change and service again, possibly something is blocked?

Regards

Mike

did you replace the filter in the auto box?

[Bounty__Hunter]

I'd consider a synthetic tranny fluid, work much better when cold.

[Mike1]

Filter was replaced with service approx 4000 miles back, and box never shifted hard when cold until around 3 weeks back, there arent any leaks and oil is clean, also havent done any river crossings so no water in oil?

Mike

[MudderChuck]

Hard shifts beat slipping any day. Have you done any top end work on the motor lately? TB or intake. Is it possible your TV cable is out of adjustment?
If the TPS is acting up and it shifts late it will sometimes shift harder than normal.

	Throttle position sensor A throttle position sensor (TPS) is a sensor used to monitor the position of the throttle in an internal combustion engine. The sensor is usually located on the butterfly spindle so that it can directly monitor the position of the butterfly throttle valve. The sensor is usually a potentiometer and therefore provides a variable resistance dependent upon the position of the butterfly valve (and hence throttle position). The sensor signal is used by the Engine Control Unit (ECU) as an input to its control system. The ignition timing and fuel injection timing (and potentially other parameters) are altered depending upon the position of the throttle, and also depending on the rate of change of that position. For example, in fuel injected engines, in order to avoid stalling, extra fuel may be injected if the throttle is opened rapidly (mimicking the accelerator pump of carburetor systems).

[Mike1]

It only does it when cold, once warm shifting is fine again, no work done on Jeep lately, only item I can think of was a trail we did around 3 weeks back, it was a moderate trail but didnt hit her on anything and didnt do any water work?

Mike

[Tarouka]

I am having the same problem in my xj 95, I changed the transmission oil, transmission filter but with no good results.
Someone told me that there are special set of sensors which gets week and should be changed, others said I should reset the computer!!!
anyway I changed the type of fuel and began to use "octane 95" since 5 days and I think that this problem disappeared, I wish it will not reappear again.

[Tarouka]

Hi ,
I had the same problem returned again, I searched the net so I found this site

http://www.autozone.com/az/cds/en_us...rInfoPages.htm
please read the article about TV cable adjustment as "MudderChuck" adviced in his reply, I did it myself and I was astonished to find my cherokee got completely changed and the transmission is no more hard to shift.
I wish it could help and thanks for "MudderChuck" for her valuable advice.

Throttle Cable

AW-4 AND 30RH/32RH MODELS

See Figure 6

Have a look at the pic for "Throttle Cable Adjustment" . here......
Jeep Cherokee Transmissions - AW4 Automatic - AW4 Throttle Cable Replacement