Jeep Repair: 1997 Cherokee Jeep Auto Transmission, current exchange rate, jeep specialist

Question
I have a 1997 'R' reg Cherokee Jeep 4.0L Ltd auto on petrol and LPG. After accelerating for a half mile up hill at speed, then  stopping for fuel and then setting off, the gears wouldn't change. I was later told that a detected fault will lock the Jeep into 3rd gear.  Next day, all was okay again but over a time I had stalling at junctions. Engine running was cured with oxy sensors and new catalytic and exhaust.  However, gear still got stuck in 3rd after accelerating onto motorway.  After parking up, and restarting #to reset things# all returned to normal but step down from top gear to 3rd can be jerky at low speeds.

I took the Jeep to an auto transmission specialist but his machine only had 2 programs and he said gearbox was older than their machine could work with.  I used to use an independent Jeep specialist who was brilliant - but in our last recession, he disappeared.  Now I am left with main dealers.

Because I am now short of funds, after the engine work, I took a chance it was the output speed sensor on the side of the gearbox casing.  However, having changed this, with no noticeable improvement, I think it's something else.  The cost of having a proper test analysis is an hour's labor and then the cost of fixing.  In the UK, labor is #at current exchange rate $176 an hour!  So it would be that cost to test it on the right machine, plus whatever labor and parts would be needed to fix.

At no time have I had the engine check light come on or any other visual fault warning. (The light works normally at start up and then goes off#.

Any suggestions of typical/common issues and/or things I could try - before resorting to the main dealer - would be appreciated.

Thank you.

Answer
There are many common problems, both electrical and hydraulic, that could be the source of your transmission concern. But without have a proper and complete transmission diagnostic performed there is no way to determine what will fix the transmission. I'd advise you to spend the money on having that done instead of throwing it away on guesses.