Transmission will not shift to third and fourth when warm

TNB13

MEMBER
2002 JEEP GRAND CHEROKEE
4.7L
V8
4WD
AUTOMATIC
216,000 MILES

I have the vehicle listed above it is supercharged h.O. Pos. When cold the transmission shifts through gears like normal. After I drive it for five minutes suddenly it will not shift out of second into third. While I can hear the engine sounds as if it is going to shift I do no't hear or feel the transmission do anything. If I go to fast the car will jerk a little as if I slammed my brakes (I do not drive it because of this. I was only testing it out after replacing the TPS. It is good on fluid and even put Lucas transmission treatment in it. What would you recommend doing?

Friday, February 16th, 2018 AT 8:28 AM

2 Replies

ASEMASTER6371

MECHANIC
52,796 POSTS

Good afternoon.

The first thing I would do is change the transmission oil and filter and add a can of valve body modifier and see if that takes care of it.

It could also be a failing seal or piston in one of the drums.

Roy

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Friday, February 16th, 2018 AT 9:31 AM

KEN L

MASTER CERTIFIED MECHANIC
54,601 POSTS

Hello,

This can be a shaft speed sensor. Can you run the codes to see what comes up?

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Please let us know what you find. We are interested to see what it is.

Cheers, Ken

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Friday, February 16th, 2018 AT 10:19 AM