This actually goes back to my post from late last year, so I'll recap briefly:

My '89 745T had an alloy case M46 with the late P-type OD. Second gear was hard to shift into. After a few days, it became impossible to shift into second anymore. I was bummed...

Well, in my garage sat a free M46, iron case, J-type OD, with the 240 shifter bracket, etc... Sure felt crisp shifting it through 1-4 on the floor, so I swapped over the necessary exterior bits and put it in my wagon. I hoped for the best with the OD, but this OD was clearly AWOL - no response at all to my repeated pushbuttoning. I verified the solenoid was good, even swapped over the known-good solenoid from my bad tranny. Still no luck. I was bummed again...

Took off the nonfunctional OD and opened it up to find the sliding clutch cracked around 60% of its diameter - not a good sign. The pistons were also the old, old type with skinny O-rings. I replaced the sliding clutch and installed the new style pistons with the fat O-rings. Everything else looked clean, moved freely, etc... I was so sure this would work, I filled up with Redline Racing ATF. Unfortunately, I still got absolutely no response from the OD. At this point, Duane gave me some food for thought on what the problem might be, and I drove on until I had time to break it all apart again. Bummer...

The time to break open the OD came unexpectedly. As I accelerated down a looooong entry ramp to the highway, I hit approximately triple-digit speed when the OD shuddered and engaged! This would have been great, except I didn't press the button. Nor would the OD disengage when I did hit the button. OD was stuck on from that moment onward in all gears, 1-4. Stopped and sat for a couple of hours - OD was still locked on. Bummed once more...

Which brings us to the present day. Now I've split the OD apart again and opened up the PRV plug and the pump plug. The pump spring, ball, etc... look fine to me. The PRV (I have the late style as indicated in the Green Manual) had two issues I could see. One, the O-rings on the outer sleeve and inner sleeve seem to be worn. Two, the little hole in the tip of the PRV (and the two exit holes in the sides of the tip) has some significant crud buildup/blockage, as well as the metered orifice coming into the PRV from the solenoid. The valve seat is firmly in place, resisting all efforts to tug it out, so I reckon those seals are good.

So my question to the Guru, et al, is: could the crud I picked out of the PRV tip, the bad O-rings, and the cruddiness of the metered orifice cause the behavior mentioned above (no OD function at all, then nothing but OD after a high speed burst)? Everything else in the OD seems to be in great shape, with the possible exception of the pressure filter (I cannot open that plug for the life of me.) Any input would be appreciated before I put this thing back together again. I do not wish to be bummed one more time...

http://www.brickboard.com/FAQ/700-900/SpecialTools.htm#OverdriveTools

I do not know what you are using to remove the caps but this homemade tool makes it much easier than methods I had used in the past (punch and hammer).

Randy

I bought an adjustable spanner from mcmaster-carr, then added a pipe over the end for extra leverage. That filter plug is seriously tamper resistant!

If there is that much gunk in there, it could block proper fliud flow and prevent then lock on everything.

With that much stuff floating around, you do need to get the large filter plug out and clean or replace the filter. I have a feeling there is no filter in place or it has been damaged.

You also will need to get the PRV seat out. If there was stuff in the valve top, there is probably more in the top of the valve prior to the dump slot.

Since it is stuck so well, a bit of force will be necessary. Spray some PB Blaster or similar up partially through the center hole, attempting to get the end of the tube stopped in the hole in the side of the valve seat. Also spray around the bottom of the seat at the edges of the bore. It will provide some lube as you pull the valve down.

Find a poultry lacing kit at he hardware store or supermarket. The Stainless Steel skewers have a nice right angle bend and the metal is a lot stronger than any wire or small picks you have in the shop. get the hook end up into through the hole, you may have to grind a bit off the end to get it to fit, then follow with a round screw driver shaft or 1/4 inch wood dowel to hold it in place. Grab both skewer and holder with a vise grip which you can then lever down or drive with a small impact tool.

Also, ther is a small passage between the bottom of the PRV area and the solenoid. Internal to this "large" hole is a small plug with a pin hole used to meter flow rate. With the amount of stuff at the top of the valve, I am pretty sure this is plugged which is preventing the OD from releasing to off. blow through from the solenoid side to the valve.

Duane

Thanks Duane.

There was some crud in the little orifice, I managed to blow that out. I will get the seat out and somehow open the filter plug to check those areas.

PRV = Peugeot-Renault-Volvo, a V6 engine.

Very funny, you PeRV... :)

In the case of the Laycock OD, PRV = Pressure Relief Valve. However, it is conceivable that most of the world's problems can be traced to the original PRV V-6...

Sorry for the confusion.