Transmission slipping?

93' 4.0HO NP231, 125K, AW4, stock DD

I've never really experienced a slipping transmission until today, so i wanted to bounce what i experienced off of you guys.

While under load and going up hill, it felt kind of like a jerking motion. at first just once then i would continue to accelerate, then it happened a few times in a row, spaced out by a second or two. i let up and then tried accelerating a bit slower and it was fine. it just happened so i haven't even had a chance to check the fluid level yet.

Does that sound about right? i haven't changed the trans fluid in ~3 years im thinking. i have the filter, gasket and fluid, so i will do that this wkend.

i have heard that these AW4's will last the duration if properly taken care of, anything i should look at while i have the pan off? i also need to check the trans mount, as it felt like it was giving a pretty good lurch when it was slipping.

thoughts?

thanks for your input!

Slipping usually doesn't feel like a jerking. More often you will see the engine revs climb with no change in vehicle speed.

not really seeing the engine revving higher while it is happening, more that it is just not accelerating smoothly.

maybe just need a tune up? or could be the transfer case as well?

Tune it up and service the trans for starters. Actually sounds engine related to me.

i am going to do a pretty full service on it soon: trans, tune up, new hoses, flush coolant and replace thermostat, dif fluid change in both difs, TC fluid change.

come to think of it though, i put in rotella 15W40 on my last oil change about 1000 miles ago, when i normally use 10W30. i wonder if that could be part of it.

Oil ain't part of it.

Agree with cruiser 54, oil isn't your problem.

Perform service on your transmission, (use Dex/Merc III compatible fluid) and also verify or better yet replace tuneup hardware such as plugs, wires, cap, rotor, and a bottle of high quality fuel system cleaner such as BG44K, Techron, etc. which can help optimize fuel injector spray pattern.

Then see where you are at.