olrik_wonderer

I bought a new set of plugs and cap and button last week. Just need to find the time, and a warmer coat to change those again. I probably need to get teh plug wires too, but I hate paying for them when I have a life time warrenty on the set I have on now. This tranny thing is just driving me nuts. At first it slips back out of OD, but if you gradually get up to speed it shifts just fine, but if you floor it, it just hangs and doesn't want to go into OD unless you slow or feather the speed. If the tranny fluid wasn't so high, I could care less as to how many times I changed the fluid out.

cruiser54

How old are the wires? How many miles on them? Do the connectors!!!

byrinxx74

Tps sensor had same problem. Changed it and shifting came to normal.

olrik_wonderer

LOL, I love that cruiser54, always state the obvoius. LOL
I replaced teh TPS sensor today. Nothing changed. Except I have a new TPS sensor now. LOL The old one did break in half when I pulled on the plug to take it off. So either way I still have to have a new TPS sensor. I'll post a reply about the connectors by 9am in the morning.

cperk

Well, it has been a long time since I started this thread but I am back in the area and working on my Jeep again. The first thing I did when the problem started was replace the TPS and reset the cable. Then I took it to a transmission specialist who told me I was getting codes for bad shift solenoids so I replaced those. That seemed to help for a little while but then I lost overdrive completely. My Jeep would drop into 3rd and the only way to get it out was to put it in neutral for a few seconds then back into drive. I finally found a used TCU (Jeeps run forever so there aren't many in the junk yards around here) and put that in. So far it seems to be running fine. I took it on a few 50 mile trips and haven't had any problems. I think I may go ahead and hit those connectors anyway though since it only takes a minute.

On a side note - if anyone ever finds themselves in Seaman Ohio I can tell you which transmission spec to NOT go to. My Jeep sat at his shop for 6 weeks so he could swap the solenoids. What I got back was a Jeep that did not run better, had a fried battery, had too much fluid in the transmission, and had a destroyed CD player. Apparently he thought it was a detachable deck so he pulled until the entire front ripped off of it.

olrik_wonderer

Sorry to hear about the radio.
Ok today has been a really ugly day. Nothing but go here, go there, go back over here, then try back over there again today. I put 110 miles on my jeep today, 40 of it was highway at about 62MPH. This is just a weird tranny problem. But then again, it might just be those pesky wires.

Trip specs today.
8 miles to work. Top speed 50 MPH (tranny OD problem.)
20 miles round trip for company parts. Top speed 65 MPH (tranny OD problems.)
8 miles to home. Top speed 50 MPH (No tranny OD problem.)
15 mile round trip to dentist. Top speed 50 MPH. ( No tranny OD Problem.)
8 miles to work again. Top speed 50 MPH (No tranny OD problem.)
20 miles round trip for company parts again. Top speed 65 MPH (No tranny OD problems.)
8 miles to home again. Top speed 50 MPH (No tranny OD problem.)
15 mile round trip to fix brother inlaws radiator. Top speed 50 MPH. ( No tranny OD Problem.)

I hope this isn't the calm before the storm? Could it have been something as simple as some grunge stuck in one of the solenoid bores and the vibration and higher spped running in OD could have cured itself??? When I have time to get my hands on some contact gel, I'll do the plug thing.

Ok, I am assuming that the TCU is the Transmission Control Unit/Module. Question? 1. Square Dimensions?(Rough Guess) 2. Location?

cruiser54

See Post # 17.

cperk

The Transmission Control Unit is in the dash on the passenger side under the long panel that your ashtray is mounted in. The panel runs across the whole dash. It's about 1 inch thick, 3 inches wide, 4 inches long, and has one green and white connector on it. When you pull that panel it's pretty much the only thing you'll see in there. It's pretty easy to get to - pull 8 screws or so (I didn't count) and it's held down by 2 nuts. You can get the computer for around $50 at a junk yard and I changed mine in about 10 minutes.

I would still try the connectors under the hood they are talking about though since it is practicaly free. I would have done it first but no one had talked about it before I went through the rest of this.

agosto4x4Cherokee

I'm have similiar problems with my 89 xj 4.0
my tranny shifts at the right time, do only problem I'm having is that my jeep is not downshifting when I floor it all it does is suck in air and slowly go up in speed. I changed the #3 solenoid since the snap on tool said it was off the entire time. but still shows the same. I tried adjusting the cable the way I read here still no luck, i even changed the TCU and still nothing. 1 thing i noticed on the valve body was that the cable was loose (could this be the problem) im gonna change it sometime this week. but if anyone has any other ideas im all ears!!! PLEASE HELP