Torque converter lockup

[Army_yevich]

'92 rodeo with RWD and the 4L30-E automatic. The thing runs like a champ, even with a cracked radiator, hardly even breaks 200F. Problem is that the torque converter will not lock up in D. works in 3 just fine, and will work in D if i pull back ever so slightly on the shifter, checked the linkage for a misadjustment, and even backed it down a hair, no change. after about an hour of driving it will stay locked up without holding the shifter but if i hit a bump on the highway, it may or may not unlock. was thinking solenoid, but it really can't be that simple can it? possible TCM problem? help!!!

[Ramblin Fever]

How many miles you got on this rig? Sounds like you've maintained it really well, but what has your maintenance interval been with the fluid change outs?

I know my '91 Rodeo, which you confirmed also had the 4L30-E tranny had a transmission dipstick, which made it easy for fluid swaps. I'm not sure if your '92 has the dipstick though - my '97, with the same tranny, has no dipstick, which makes it a pain in the arss.

[Army_yevich]

yeah i've got just under 80,000 i've been to iraq twice and my wife has been out of state for the deployments, so unfortunatly it has sat for a couple years, i change fluid and filter every time i get back, and yet the problem remains exactly as it has. i'm leaning towards an electrical contact problem (sort of like the one you can get with a blower switch only working on 3 out of four settings or only working in that in-between area, i was just looking for a second opinion before i started tearing the transmission apart. i try to keep up on the truck, but its keeping me busy. i've just replaced the carrier bearing 2 u-joints and both collector gaskets. in the future i'm going to need a gearbox a little bit of bondo and i'm looking into buying a locker for the rear end (as its cheaper than buying a transfer and front end). i've also got the same ALDL bit... i've worked around many older model vehicles, this is the only one where i still haven't located the ALDL, and i my check engine bulb took a poo on me and won't light up anymore so i'll have to rip the dash apart to change that someday too. not too concerned, i make about 23 on the highway as an average.

[Ramblin Fever]

First and foremost, I want to thank you and your wife for all that you're doing, I can't even fathom how hard that is, in going to Iraq and being separated from one-another. My hats off to you and your wife and may faith bring you both home always.

Do double check for any electrical gremlins, other then that, I've got to be honest, I haven't had any tranny issues to assist.

23mpg is great!

Wow - 80k miles, I've got almost double.