Hi guys just wondering if anyone has any thoughts before i take it for expensive garage work

I bought my 2011 barbarian auto in Oct last year with the idea that it would be the ideal tool for towing the horse trailer we were renovating and our heavy(ish) caravan, well that and the fact I had always wanted one and it was a good excuse.
It did not have a towbar fitted and shoed no signs of ever having one so finally when the trailer was finished and the touring sites re-opened I got my nice shiny new, big enough to tow a bus, towbar fitted and off we went. The horse was loaded and off to first show on and off a muddy field with no problems whilst others struggled. then the caravan, first visit to a local site was so uneventful I forgot it was on the back at times towed like a dream.

Then this last weekend a trip up into the Derbyshire peaks near Ashbourne and if anyone is familiar with the area, some formidable hills.
Fearing nothing with my beast I chose a route away from the dual carriageways and heavy traffic on a Friday afternoon and for the first twenty miles no problems. Then we reached a long windy hill section and it felt at first like it was laboring then some high revs as if the clutch was slipping on a manual. I quickly knocked it into neutral then back into drive which appeared to reset it an we carried on ( given the lorries and heavy traffic on this route it was scary not to) It was then that the red A/T temperature warning light came on and the truck was struggling even more. as if by a miracle suddenly a lay-by appeared and we managed to pull over and switched off the engine and sat there for about thirty minutes.
We set off again and reached the pinnacle with no issues, a few more shorter up and downs caused no problems until we had a very steep but short climb up to the campsite that i feared at one stage we weren't going to make again having to reset the gearbox a couple of times, finally setting up and having a well deserved beer.
Next morning we decided to give it a try around the area with nothing attached, up and down hills like a dream gearbox changing just as it should even the steepest climb was no problem whatsoever.

Then the return journey, deciding on the more arterial route the first few hills out caused no issues. 15 miles down the route we hit a long slow climb on the A38 our speed dropped to about 30 and the box stared to slip again. Once again after reaching the top we found a lay-by and rested for about twenty minutes and then managed to complete our journey home, a few more shorter hills were covered without issue.
About half an hour later after putting the van to bed at the storage facility i took the return journey home via as many hills as I could find, the truck did not even notice they were there.

So as I said before I take it to the sharp intake of breath specialists, is there anything I should be looking for that a complete idiot could understand?

Thanks

john

It sounds like the A/t fluid is overheating, now I'm not 100% sure but I think ( and stress) think there was a recall for an auto box cooler? Do an mot check on the .gov website and there is a section for recalls outstanding, have a quick look there

Had a look on .gov which shows no outstanding recalls and also on https://www.vehicle-recall.co.uk/make/MITSUBISHI/L200 which has nothing related to A/T fluid or auto box cooler.
Not much else on interweb at all

Ok , I could have been imagining it LOL. mY first port of call would be to get the automatic transmission fluid changed , along with the filter ( think they have one )...could be old fluid and a blocked filter causing the fluid to not be moving about the box correctly

HAve a read of this old thread ( before it gets deleted LOL ) 2013 L200 auto gearbox problems whilst towing

Yep that's exactly what happened to us.
Strange thing is that our truck had never towed before, there was no indication that a bar had ever been fitted.
That thread was 6 years old and one truck having the issue, i see hundreds ( may be a slight exaggeration) of L200 towing far greater weights one the same year flew past me on the uphill stretch of the A38 with a van on the back. OK could not tell if it was a manual or not, but one reported incident on here in over 6 years? seems a little odd to say the least!
I needed an auto box due to health conditions and found the perfect vehicle but must have been the only one I have ever seen without a towbar fitted.

Jumping to the other thread on the link reveals the following
"Ahh i see, that post i put up is from a member of the Malaysian forum and mitsi fixed it as a recall as he complained.... but they'll only fix it if it is a complaint!!!! Rather than doing a mass recall even though they know it is an issue
I agree Twed, the result is that the oil gets over the programmed temperature in the ECU and it immediately shuts down the gearbox. There is a fix that can re program the temp setting in the ECU but I have read a couple who have had that done and it failed to fix it, both new trucks and Mitzi had to fit an Auto fluid cooler on warranty, apparently quite expensive.
Seems they may be adopting the old British Leyland policy of manufacturing something and letting the customers road test it to find the faults.

So where does that leave me? I have a 10 year old truck bought nearly a year ago and left it till now to tow thanks to that damned covid, never had a problem with it until now so way out of any warranty.
No sign of any recall on the .Gov.uk website so apart from a trip to Malaysia (if there are no hills on the way) where it appears they are aware of the issue and fixed it I don't appear to have many options apart from a. stop towing uphill b. part ex it, which i don't want to do c. pay for a fix that no one seems quite sure what that is or if it works.

Compared to the Gunong Korbu (2,183 m/7,162 ft), the Peak district hardly warrants the name and a June temp a balmy 14 degrees so if I can have an issue dragging the shed up that little hillock in comparison not to mention a steady gradient on the A38 on the way back it must surely be a more widespread problem and yet little or nothing to report.

So I wasn't imagining reading about a cooler then lol. It may be worth approaching Mitsi just to see what they say, I'd go straight to customer care at Colt Car Company rather than your local dealer

Have you actually checked the gearbox oil level? Need to do it with a warm gearbox and the engine running

Yes did check looked ok but no overconfident in what i was doing.
no towing planned for a while and its going in for MOT next week so will get my friendly garage man to give it the once over whilst it is there just to be on the safe side.

Update
Oil checked by mechanic all fine.
Checked paperwork that came with motor as I did see a bill that I took with a pinch of salt at first.
Contacted the garage and the specialist that did the work (£2540 worth) over near Kings Lynn
On 17th July last year it did not have a towbar but was constantly slipping out of gear and was sent to specialist where it had "drain transmission, change gearbox oil filter, fill with oil, strip and clean transmission, overhaul and re-build, clean out cooler and cooler lines, re-fit transmission with rebuild torque converter"

Some time after that it had covered another 1000 miles before arriving in Doncaster where I bought it late September last year. It has done another 6000ml gearbox trouble free until i towed the van even now ok without it.

The gearbox chap over in kings Lynn has said it would be covered by warranty for anything he did but personally I suspect that everything he did was good and there is something else as we have spoken about on here.
i am going to take it locally and get a read out of what the onboard computer is saying and then discuss the results with him before deciding what to do, trouble is Kings Lynn is about 2:45 from me so not that easy to get picked up if he needs to keep it.

Update
Oil checked by mechanic all fine.
Checked paperwork that came with motor as I did see a bill that I took with a pinch of salt at first.
Contacted the garage and the specialist that did the work (£2540 worth) over near Kings Lynn
On 17th July last year it did not have a towbar but was constantly slipping out of gear and was sent to specialist where it had "drain transmission, change gearbox oil filter, fill with oil, strip and clean transmission, overhaul and re-build, clean out cooler and cooler lines, re-fit transmission with rebuild torque converter"

Some time after that it had covered another 1000 miles before arriving in Doncaster where I bought it late September last year. It has done another 6000ml gearbox trouble free until i towed the van even now ok without it.

The gearbox chap over in kings Lynn has said it would be covered by warranty for anything he did but personally I suspect that everything he did was good and there is something else as we have spoken about on here.
i am going to take it locally and get a read out of what the onboard computer is saying and then discuss the results with him before deciding what to do, trouble is Kings Lynn is about 2:45 from me so not that easy to get picked up if he needs to keep it.