2001 GMC Jimmy Tranny problems?

[MarthaPlimpton]

My 01 Jimmy won't shift into 4th gear. It's a V6. Has about 75k miles on it. It worked fine this weekend....but now it's not shifting into 4th. I feel it shift from first to second and second to third. Then it just runs high and won't shift. Any ideas?

 

[fenixat1]

then you need to have your transmission looked at

 

[zbelle]

Change your fluid and filter. I change mine with every other oil change. (I have a 79 Chevy van with over 200K on it. I've rebuilt the engine, but my tranny's still good.) If that doesn't help you'll have to overhaul it.

 

[eshamn]

It is a good idea to make sure that when you get it fixed you take proper care of it. Taking it to the shop to have it diagnosed is a good idea... that way you know exactly what you are dealing with and how much it will cost to fix. My guess would be that you can probably fix it pretty cheaply by getting a tranny kit. But take it to a shop and find out whats wrong with it and what you could do to fix it.

 

[Saturday Morning]

How cold is it outside? Many vehicles won't shift into 4th or overdrive until the engine transmission have warmed up - if it's real cold outside it may take a while. Other than that:

1. Check the AT fluid level - read owner's manual to find out how. Many times engine and transmission must be warmed up (10 miles minimum)and left running with AT in park and vehicle on flat ground.

2. Control system (valve body) failure: like the solinoid that activates TC lockup/4th gear may have quit.

3. Hard part failure. I believe that on the 700R4 a fracture of the sun/orbital gear will cause this -but you also loose reverse.

4. Torque converter failure. If the TC lockup function has failed the transmition may intentionally stay out of 4th gear/overdrive.

sorry. good luck!

 

[Mari]

Either take it back or take it to the shop...