Weird Tranny Problems

Hey guys,I am new to the site and need some help.I have done a search,but nothing really fits my problem.I have a 96 cherokee 4.0 auto.The other day while driving the trans just jumped from od to 3rd and wouldnt shift back.Then when I came to a stop it tried to take off in what felt like 2nd or 3rd.I made it hope cut it off next did fine no problems at all.Then today its back.I have noticed that when I touch the brakes the Torque converter doesnt lock up.When you give it a lil more gas it does.Does this sound like an elictrical prob or the trans.It just comes and goes.Any help will be greatly appreciated.

Any number of sensors could be out and I'm sure that someone better at transmission stuff than me will be along shortly.

In the meantime, how many miles on yours?

I had similar shifting problems with my 2000 4.0 when I needed a Crankshaft Position Sensor. Have you tried getting the codes? From vehicle off, turn the ignition on (until gauges light up) then off 3x in 5 seconds, then leave on. The odometer will flash up a series of numbers. Let us know what those are, and we'll be able to help better.

Its a 1996 2wd 4.0 auto.It has 188,000 miles on it.Never had a problem with it till now.Bought it brand new in 96.By the way what type of tranny does it have?

AW4 auto trans.

Drain the fluid and see if it is dirty, smells burnt, or have metal particles in it.

Pull pan if you think necessary. Look at filter for debris.

Refill and flush by draining again and running. Search for previoous posts on this.

Or go to a trans shop for diagnosis and testing. They have gages for pressure testing.
Since it is a 2wd, the transmission is easy to pull and rebuild.

Take a look at you MAP sensor and the vacuum line running from the throttle body to the MAP sensor. A bad MAP sensor or leaking vacuum line to MAP sensor could cause erattic shifting like you describe. I had an 89 do the same thing, it ended up being the vacuum line to the MAP sensor.

Ok guys.I checked for vacuum leaks and no luck.Now around 65mph the torque converter is locking,raisin the rpms about 300 and staying that way.When I give it a lil more gas the rpms actually drop.Then when I level off they jump back up again.Could it be the TPS?

Have you gotten any codes from the system? Checked the trans fluid?

I've got a similar but different problem with my 91. Mine tries to lock, bangs and does not engage... Now, it's started "neutralizing" while driving. From all the testing and research I've done, it sounds like the "lock-up" part of the torque converter is failing. Try what everyone said already. If none of this stuff works, it's likely converter time. If there is an unusual amount of metal on the trans pan magnet, this is a pretty good indication that something is coming apart. Mine however didn't have any when I checked it but I'll bet it does now!
Keep us posted!

Well guys.I changed the filter and fluid,then had the codes pulled.All that showed was an oxygen sensor.What I dont understand is when I cut the switch off and back on it drives fine for a while.Any more suggestions will be greatly appreciated.

Please clear a couple of things up first.

Do you have a check engine light? (You said they pulled up a code.)

What switch are you refering to when you say "when I cut the switch off and back on it drives fine for a while"?

Just for the record, I've experienced the exact same issues from a dirty at first and then misaligned NSS. (Neutral Safety Switch)

Also affecting my tourque converter for a short spell and suddenly turning into full shutdowns at highway speeds was the CPS (Crankshaft Position Sensor)

~Good Luck!!

Alos.. lol.. This thread seems to attack the same issue about now...

http://www.naxja.org/forum/showthread.php?t=943519

Thanks for all the help and info guys.I have noticed one other thing,If i drive 75mph or higher is does just fine.It just does it between 55 and 70mph.I think it may poss. be the throttle postion sensor.I have checked the vacuum lines,grounds,changed fluid and filter,also had autozone pull codes.Could it poss be a worn spot on the tps?Thanks again for all the help.

well, I don't think it'd hurt to get a new one on there (DIY) just to see if that's the case.. you can always take it back.

Hey guys,The problem is still there.Today I pulled the fuse under the hood to the tcm.I manualy shift it and it does fine.No jerking or the down shifting for no reason.Could it pss be the tcm?