All Info About Auto Repairs
Your One Stop Source For All The Information You Need For Your Vehicles.

Questions and Answers

Up And Down... In And Out

Q. I have a 98 Jeep Cherokee, 4.0L Automatic. I'm pretty unhappy with the way that the transmission downshifts, especially at highway speeds (60mph+). Driving in the high plains (NM, CO) with A/C on into a head wind, it wants to continuously shift between third (very high RPM) and fourth gears. This engine has enough torque to push the truck, but the transmission doesn't seem to know it. Maybe this is OK for the engine, but it's very annoying.

Is there anything that can be done to change the shift patterns to make the Cherokee keep its RPMs down?


A. I agree with you wholeheartedly. My 1987 Nissan Van does the same thing. Unfortunately, there's not a whole lot you can do. These are what we call, "busy transmissions". The A/T Control Unit tells the transmission when to shift from third to fourth and back again. It get's some of the information from the EFI control unit and based on engine load and vehicle speed, it shifts between the two gears.

There may be a modification to help smooth it out, but you would need to go to a transmission shop to see if there is and what it entails.

Back to Index

Additional Information provided courtesy of AllDATA and Warranty Direct
© 2000-2008 Vincent T. Ciulla

FREE Newsletter. Sign Up Now!

Help keep this site free

Search All Info About

Related Articles