My mate has had on-going issues with his current Grange with transmission problems. Every time he goes on a trip, or has to spend a long time crawling in traffic, the transmission goes into limp-mode and stays locked in, I think it's 5th gear. Just jams in 5th and won't change up or down until you let it sit for 15 mins to cool down, and reset by turning ignition on and off several times.
He's had it back to Zupps at Mt Gravatt here in Brisbane probably 10 times complaining about this specific issue. They have fitted an external oil-cooler, several re-flashes of software, oil-level checks, and last time, a new torque converter, all to no avail, and in fact it has been getting worse.
This morning we took it to Fulcrum suspension to discuss some shock-absorber issues, and having a look underneath on the hoist, the transmission problem immediately became obvious, even to my non-mechanically-minded mate.
Some genius first-day apprentice has fitted the oil-coooler and connected it to the original in-tank cooler in the bottom of the radiator........but has disconnected the pipes from the transmission to the radiator and just connected one to the other with a "U"-shaped loop of hose !!
So, now the transmission oil travels from the transmission, down the pipe to the U-hose and back to the transmission, completely by-passing both the original radiator-cooler and the new external cooler which does absolutely nothing since it's not even in the oil-circuit .
If it wasn't so bloody frustrating and stupid it would be funny.
So, guess who will not be back to Zupps for his next (4th) Grange.