The S5 has a safety feature built into it, that if the solenoid open circuits, it goes to maximum line pressure to prevent the transmission burning out - Giving rough upshifts & thumping when coasting back down through the gears. The other 7 solenoids are shift control solenoids.

If you lower the rear of the valvebody, you can get the S5 out without taking the valvebody completely off - It saves trying to re-align the manual valve, Z-link & detent if you are doing it by yourself.

i rang up a few places today.

and went over some fish's on my gearbox to get the ford part number.

$650 for a S5 solenoid FORD GENUINE PART.

$250 for AFTERMARKET UNIT through my work at trade price.

so before i go all out, does anyone reckon its worth having the transmission professionally flushed?

my problem is this to be exact.

after about 30mins of driving from cold in stop start traffic. the gearbox will THUMP/THUD/SNAP 2nd gear, then from 2-3 it will rev out before changing almost like a double clutching action. 3-4 is fine. and there is no difference in the downshifts.

but for $250 i reckon i could buy an entire transmission from the quokka.

What was the oil like when you took the pan off the first time? Burnt?

Try pricing a Holden VR - VY 4L60E pressure control solenoid, or "force motor" as GM likes to call it - It is the same solenoid thats used in Ford EA - AU BTR auto's & it is usually a LOT cheaper!

If you still have the old filter that came off it originally, Open it up & see whats in the Dacron lining inside - If a clutch is wearing out, the material will be inside the Dacron lining & not in the pan - The material that lays in the pan is metal sludge on the magnets or brass particles from the heat exchanger in the radiator coming apart.

If you can put a scan tool on it when it starts playing up, It will bring up the code for a crook S5 to be 100% certain before laying out the dollars.

I don't think it's worth it. I just replaced a gearbox for my brothers car as it was getting worse. $300 for a second hand BTR for an I6 that had 3 months warranty. So it depends on what you can get a second hand gearbox for. Once you have the old one out, you could then strip it down and fault find it in your spare time.

i mean how much would i be looking to have someone install a transmission?

given that i track down or buy another transmission?

there was metal sludge or grease over the magnets in the pan when i inspected it.