Sir,
I am facing slipping trouble but only in reverse, both conditions hot /cold
2 times transmission opened up but problem is still,
I replace quad rings, friction discs, but didnt change metal rings because its look good and scratch less. Same parts replaced in forward pack also, which is working correctly.
I also found that orifice plug which you discussed above, partially broken and its thread has been slipped. But i didnt change because that part is not available at dealer.
I also checked it at another daewoo truck by removing this orifice plug and didnt found any change.
Please help.