OOHHH, now I have to dig deep!
First I had a 1200 mile trip on flat autoroute, then I came back and was asked to haul a empty but big caravan, and I was not allowed to use the peage (tollroads) so I found myself in very faul weather on a very small curvy steep mountain pass at night, not knowing nothing about that OD button.
The first 1200 mile went smooth, almost empty. than back home a few days later I hooked up a big bumperpull trailer, which made my truck as long as a semi. and then we went to get that caravan. and after that I had to deal with that mountain pass.
this is about 4 years ago, so please bear with me.
I forgot a bit when it started hunting through the gears (If i remember correctly?) but I think after when I attached the trailer? it was a nice day and over the peage it didn't give any problems apart from maybe hunting through the gears ? (It's also possible that only started after we loaded the caravan on the trailer? can't remember)
Anyway, on the way back certainly on that pass, problems started, hunting through the gears, hearing shafing sounds, couldn't stop due to no shoulder and lots of traffic honking their horns behind me, at a certain point it started to smell hot (oil), and on accelerating it stayed very long in 1st,2nd gear, and really revving up before go to the next gear.
At a certain point I dicided to get of that pass, but instead of going to the same type of road, but less occupied, the bloody TomTom take me on a goat trail!!!, so 4WD Low gear, and pulling through, my god, what a horror! anyway, we made it, But the last mile or so, the trans had much difficulty with pulling away in a normal fashion, instead it ran at least at 3000Rpm before switching over to the next gear. and we came on a crossroads, where I stopped to look for the right direction, and at that very moment,I heard something like a "splouff"or something, and a cloud came from under my car, and rightaway it started to smell like very hot atf oil, and I heard something like "sploufsploufsplouf" then when I got out and looked under the truck, it was all wet with ATF. It had vomited all through the rear seal.
At that point I had to call for the wreckers.
when the truck was back home on the forum they told me it could probably only be the rear seal, which I replaced,filled with new oil, and then as soon I choose the "D" gear, started to "sploufsploufsplouf", which didn't dissapear,
so I new something was very wrong there.
Later the guy from the trans shop told me that the torque convertor's clutches were completely burnt. and then some.
Oh, and that delay if you select R is still there. I'll try to find some images from the load that day. and from the standard trans cooler FORD used at the time.
And in the meantime I also installed a VDO trans temp. gauge. I now think that's a very important piece of kit!