transmission is shifting late and hard.

2000 JEEP GRAND CHEROKEE
175,000 MILES • 6 CYL • 2WD • AUTOMATIC
Avatar
JOSH88
  • MEMBER
  • 1 POST
whenever i hit the gas the rpm's go up normally but when it gets to the point of shifting into second gear it will keep on reving up until it finally shifts. It's very noticable and it just shifts very rough. It does it with all the gears; its worse when ever i give it alot of gas. The transmission could be going out,but who knows it could be something simple. Thank you.
Aug 6, 2011 at 6:48 AM
Advertisement
Avatar
CARADIODOC
  • ✓ASE Certified Mechanic
  • 34,321 POSTS
  • ASE Certified Mechanic
Older transmissions had a cable that would stick sometimes. I checked rockauto.com and they show a "modulator" for your vehicle. I don't know where it lives but given the o-ring in the photo and the fact it measures engine vacuum, I suspect you'll find it somewhere on the intake manifold.

There could be a problem with this unit but first check for a vacuum leak. That would cause the same low vacuum as when you're accelerating. The Transmission Computer will interpret low vacuum as heavy acceleration and increase the shift speeds and harshness.
Image (Click to enlarge)
Professional Diagram for 2CarPros Members
Click here to log in and view diagram.
Aug 6, 2011 at 7:57 AM
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.
Ask a Free Question
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.