Chick-N-Picker

Yes sir, I checked that connection thanks to you about 1.5-2 years ago when I first got the Jeep. It was clean and tight then and still is today when I checked it.

I also loosened the lower dash and checked the TCU plug. It was very clean and plugged in good.

I went ahead and changed the TCU fuse to another one. I reckon today or tomorrow if I get the chance I'll swing by the JY and hopefully grab a couple TCU's and pray it solves it.

But I did remember something. About 2 hours before it messed up the speaker in the driver door started crackling. I think it did this because my window handle rolls up but about half way it pops and then continues to roll up. I reached down and wiggled the handle and the crackling stopped and the speaker no longer plays music. Not sure if the two could be connected.

cruiser54

Probably not connected.....

We're beginning to see TCU failures lately. They're all pretty old.

Start snagging them at the junkyard whenever you can.

EZEARL

For those of us whose only access to jy's are hours away maybe someone here could do a Big David type of offer.

cruiser54

good thought.

ALERT!!!

there is a difference in tCUs from 90 to 91. They plug in and all, but operate differently. The color of the plug must match the color of the receptacle on the tCU.

I think one is tan and another blue.

EZEARL

We had three jy's locally but when the price of metal skyrocketed they crushed everything and closed shop. Can't blame though.

cruiser54

Buttstripe, a user on here, is an excellent source for junkyard stuff.

EZEARL

Thanks. I'll make note of him.

cruiser54

Brendan and his wife Ana are friends of ours.

I don't know if you saw any of his videos, but one or two were filmed in my garage with me narrating.

EZEARL

Haven't had the pleasure. With our only internet provider it's very rare that I can watch a video. Better chance if they're not too long. Actually most of the time pics that are posted don't even fully download for me. Then there is the kicking offline issue. No relief in sight either.

Chick-N-Picker

Well. Its going to be tomorrow before i can to the JY. But im going to grab as man renix TCU's as they have. Then if anybody on the forum needs one in the future i can help them out. I just hope it solves my problem.

Ill give an update some time tomorrpw or Saturday and see where its at.

ButtStripe

Hey Guys,
Like Cruiser said I go to the JY's to pick XJ/MJ parts. Right now Ive been on hiatus as my Jeep has been undergoing an overhaul, but I should be out in the field in the next week or so. Let me know if there is anything I can help with!

P.S. I just had the same issue myself. One day I had a slight burning smell, and disregarded it. The next time I went to start the truck it wasn't shifting properly. You can disconnect the TCU and drive it by manually shifting through the gears just fine for as long as you want. The only problem is, there are three solenoids I believe and gears 1-2 are on the same one so you will only get gears 1, 3, and 4. Please correct me if I am inaccurate.

67 GMC

I'll throw in my $0.02 here (and that's worth even less in CDN dollars).

May not be the exact same problem though. On my '87, it was the speed sensor causing something similar. Jeep would drive normal first thing in the morning or when it was cool outside. When the trans got hot, it drop down to to 1st gear and rev the engine up high. My conclusion was the speed sensor mounted on the trans was getting hot and flaky. The speed sensor would short and send "0" mph (like it was stopped) to the TCU which would then interpret that the Jeep was stationary.
My quick fix was to put a switch in line with the TCU. When the weirdness happened while the Jeep was moving, I would flick the switch which would de-power the TCU, it would then default to D. It would drive fine until I slowed down to a stop, then I would flick the switch back on, powering up the TCU, and then I would have first gear to get started. Once up to speed, I would flick the TCU off and ride around in D. It was kind of like driving a manual.

I would see what happens with the TCU fuse out while stopped. If you feel like the trans is slipping and you can hardly move, you're in D. If you put the fuse in and it drives ok but revs really high, you're only in 1-2.

Basslicks

I'll keep my eyes peeled. Been thinking about snagging common failure parts while I'm at the yards anyway. Sounds like I should start doing it.

Chick-N-Picker

Update

Well I made it to the junk yard today and pulled two TCU's. One from an 89 and one from an 87.

I went home and put the 89 in. I drove for about 3 miles and so far everything feels back to normal. To be honest I didn't have much faith it would fix it.

So I guess for the time being it's back to running right. On to trying to figure out why my driver side door speaker went out.

cruiser54

I wasn't worried.....