Unfortunately, other commitments are restricting my progress at the moment but I thought I’d report on what little headway I have made so far.
I started underneath with the sump pan (20-off 10mm A/F bolts) and removed the metal & rubber gasket.
As soon as the sump pan came off it was clear that something was amiss - it looked like there’d been an explosion in a glitter factory! Everything’s covered in fine metallic debris. The guy that I got the transmission from simply said that the transmission had lost reverse.
The filter comes off easily (just pull).
Note that the filter has a spacer and two seals.
Like with the ZF boxes the filter is made by Filtran in Germany (The German border is only a few yards away from where the transmissions are built in Strasbourg, France).
The wiring harness comes out next :
…followed by the valve block assembly. This is retained by nine screws – one with a 10mm A/F head and the remainder requiring a Torx E8 socket.
Interesting to see that GM put the inhibitor (or XYZ) switch inside the transmission rather than the ZFs on the outside.
Here's the valve block assembly from underneath :
The five solenoids can clearly be seen as well as the four accumulators :
The three (identical) solenoids with the green connectors are the shift solenoids for the 1-2, 2-3 & 4-5 shifts (labelled A, B & C respectively in the casting).
The similar sized solenoid at the other end of the block assembly, with the grey connector, operates the torque converter lock-up clutch.
The remaining (large) solenoid is the pressure control solenoid whose job it is to adjust the transmission’s line pressure.
I did a quick check of all five solenoids’ winding resistances and all were to spec. (at 20 deg. C. these should be : shift solenoids = 15 to 17 Ohms, TCC solenoid = 10.0 to 11.5 Ohms and pressure control solenoid = 3.5 to 4.6 Ohms)
The two speed sensors can then be removed (each held in with a single screw) :
The sensors should have a resistance between 325 and 485 Ohms at 20 deg. C. Mine measured 387 and 389 Ohms.
The jump tubes that feed fluid from the valve block to the clutches in the casing can then be removed (they're held together by metal straps) :
Anyway, that’s all for now. The bellhousing is next and then I can start to remove the running gear ...........
Phil