2001 v70xc transmission shot or sensor?

[volvo in ny]

second change this morning,,,fluid is still black. I read somewhere that someone had shift problems and it was related to a worn bracket (dogbone?)that holds the trans to the car. I looked at my bracket and the part closest to the transmission had no rubber. The bolt was in the upper most section of the grommet hole. Not saying this is it but could it be part of it? there was daylight through the bolt hole.

[rockydog331]

My 2001 V70 is going going gone, flushed it (drain and refill ) twice ran it through the gears several times , held the brake on put in D 1 2 3 4 d r put it on the ground same . It will go for 1-2 min then forget what it's job is. The only weird thing is i can shut the car off restart and it works, Changing valve body and solenoids wast of time ? What else could it be ??? Hope all is well Walter

[precopster]

What exactly does "forget what its job is" mean can you be more descriptive? Does the car slip and rev while in gear?

If it does it sounds like a blocked filter

Best to start your own thread but we'll go with this for a while

[precopster]

Accompanying your breakdown is there a turbine-like whine coming from the engine bay when car is revved?

This is how I unblocked the filter in my T5 last year. Car still runs fine though fluid seems to get dirty quicker than I remember. You need a Magnefine 3/8 inline filter (or 2) to prevent contamination.

viewtopic.php?f=9&t=82841&hilit=unblock&start=50

[SuperHerman]

From the sounds of your transmission, specifically how it works when it starts and then starts to fail, hints at a clogged filter. It looks like precopster is of the same opinion. You have two options here, actually three. 1) Precopster's method; 2) Precopster's method and the addition of an external replaceable transmission filter; or 3) the yet to be attempted back-flush of the transmission filter from the valve body.

(I would really like you to try #3 - the wisdom of this forum would be enhanced. I think it has a good chance of working as the filter flows enough at cold start to show you have flow and not a solid screen.)

[xHeart]

Precuhfs Method!

[SuperHerman]

Check out this discussion, last 15 or so posts and pictures where the "back-flush" method is discussed. viewtopic.php?f=9&t=84857&start=30

In the hopes some member tries it, I pulled out an old valve body to take some measurements. Attached is a sketch of the post and a description of what I think may work.

First is an actual picture of the port.

This is a trace of the port.

Port Trace.jpg (222.9 KiB) Viewed 519 times

I think that one could fashion a plate, affix a fresh transmission fluid supply inlet port, and push fluid into the system and have it drain out the drain port nut. Looking at the trace one would cut a piece of stiff metal or plastic 2.5cm x 7cm to serve as the cover. What is important is the gasket and mounting holes not so much the plate. It can be a rectangle, but the two attachment holes must be exact, and the inlet port fully covered. With these dimensions there will be over lap, but it is fast and simple. It can be trimmed to size if one wants.

Using the two bolts that hold the port cover on will secure it, a washer or two may be needed to prevent the bolts from bottoming out. This could ruin the valve body so take note. Sealing the cover will be by gasket, which will have to be hand traced. The original port cover should provide a good source for the trace dimensions. Describing what is going on, the dark purple outline with purple and orange hash marks, would be a paper gasket one would have to cut. This is to seal the system so pressurized fluid could be forced in. In the gasket area, is a 10mmx10 mm square where the fitting would be attached, denoted by blue hash marks. This is a size limited spot - maximum width on one side is 10mm - the other side has plenty of space. The depth would permit a fitting to be sealed with a nut. The fitting has to be towards the top of the valve body as depth is limited on the lower end. You will see this in the picture. I think a 3/8" fitting could work, but wonder if it can pass enough fluid. Depending on skills and material, one could weld something on and create a larger inlet.

Just some ideas - I want to see someone attempt this. Even if it is a fail, it could still be used to flush debris from the drill method.

[precopster]

How close is the filter to that port? Can't be too far away...

I wonder if a compressed air nozzle could blast away enough gunk on the filter screen to make it work.

I already tried using solvents at around 50:50 ratio mixed with ATF with filter unblocked by blowing compressed air through the cooling port of the radiator. Perhaps Shellite 99% hydrcarbons was the wrong solvent.

Another poster on my blog mentioned a product called BG Transmission Flush that worked for him.....no need to fabricate plates, high flow pumps or anything out of the ordinary. Just pour can into transmission and let idle.

[SuperHerman]

I thought the concept was to back flush. If that is not it, then you are right. I could be totally confused.

Pushing fluid at a clogged screen, unless the solvent dissolves the fluid, isn't going to work. You are right - just add the cocktail to the mix and run it. Drain and refill.

From what I recall when I opened a similar transmission for some exploratory fun, the screen is on the other side of that opening. I think the idea is the fluid is picked up in the pan and runs through the filter then vents into that port. So by pushing the fluid the other way, it rinses off the screen and pushes the crud into the pan, which then drains through the drain plug.

The question is whether enough fluid can be forced to clear the entire screen, rather than just a small spot, which of course will get covered again.