Help with transmission diagnosis

[Xfingers]

FirstVolvo, all these sellers say the same thing, "with Gaskets and Seals" but they don't list any specifics. Thanks for the heads up. I bought a gasket for the pan to avoid using RTV sealant but I guess I'm gonna need those two seals ($17 at FCP). Replacement of those seals is critical? I thought I saw a video where the tech was breaking down the transmission, he noted those two seals, but didn't say anything about replacing them. I ordered a used trans harness pulled from a 2009 Chevy Equinox so I'm figuring its gonna have the longer wires for the solenoids.

Edit: FirstVolvo, FCPEuro says 274470 gasket kit doesn't fit 2002 v70XC. Their site's gotta be wrong.

[FirstVolvo]

I think it's a very good idea to replace the two rubber seals between the valve body and case and I don't know of any other part number for the 2002 model year. Not sure if the 2009 Equinox wiring harness is going to work on your Volvo, I don't know if the connectors are the same.

[Astro14]

The pan came from the factory with RTV, and that didn't leak for the first 100,000 miles. I just used RTV. Good RTV...freshly opened and on a clean surface. Still not leaking eight years later.

The two rubber seals come as part of a kit. Volvo calls the valve body a "transmission control system". Perhaps a friendly parts guy can help with sourcing those seals. I would absolutely replace them.

When I did mine, these were the part numbers:
Transmission Control System Seal kit (Volvo PN 274470, which consists of Volvo PN 30651154, gasket and 2 of Volvo PN 6843829 O-rings)

[Xfingers]

The pix of the 2009 Chevy Equinox wiring harness looked to have the same connectors and colored wires as the harness in Astro's tutorial so hopefully it'll work. I'm thinking the 2009 AW50-55 VB it was pulled from would have to be type B or later so it'll match up with the new GM VB I ordered. If not, I guess I'll use it to make a butt joint and extend the length of my original harness. I ought to be able to check the fitment with the new VB before I do the install.

Just spoke with the Amazon seller of the GM valve body. He checked and said NO gaskets or seals are provided with the valve body. He said Amazon itself controls the pictures and descriptions of its listings - they like to use the same picture/description for all sellers. I ordered Volvo 274470 Transmission Gasket kit from FCP. Thanks FirstVolvo and Astro!

[FirstVolvo]

For the 2009 Equinox wiring harness I'm not sure about the connectors on the wiring harness outside the transmission, the one(s) that plug into the main wiring harness. All the connectors to the solenoids and temp sensor inside the transmission should be the same and the wire length long enough to reach the bottom connectors on the linear solenoids.

If you do have to extend the wires you must use high quality automotive grade wire and and high heat, high chemical resistance heat shrink tubing. I have these supplies since I didn't need them so let me know if you'd like me to send the stuff to you at no cost, I just ask that you document and share the wire mods so others will benefit.

The GM valve body part should come with the small cover gasket that's installed when the valve body is installed but nothing else. The Volvo kit with the two sealing ring also includes this small cover plate gasket.

Something else that I should mention about the gaskets used on the valve body. There are gaskets between the valve body plates and end cover plates but be aware this gasket material is not your typical type gasket, it's thin, relatively hard, brittle type material so you have to careful with it. You'll see and can contact the gasket material on the valve body side surface areas that goes against the transmission case and also when you remove the end plate to remove the B5 control spring. Be careful with this gasket material, don't bend it, it will break. Ask me how I know.

[Xfingers]

FirstVolvo, here's a link to the Ebay listing of the trans harness I bought: https://www.ebay.com/itm/322993790127
If you care to look at the 2nd photo, you should see what the connection to the main harness looks like. I have no idea whether it'll be compatible. It definitely looks funky.

Thanks for the warning on the gasket material. I'll be replacing the S2 solenoid and most likely the B5 spring. Great write-up, by the way. I'm using it as a main reference.

[FirstVolvo]

I don't think the Equinox wiring harness is going to be compatible based on a comparison with the Volvo harness pictured in the link below. If it's not plug compatible you can still use the connectors and wires for the two linear solenoids that need the wires lengthened. Use the connectors and wires from the purchased harness to eliminate one of the wire splices needed. Just adding a length of wire would required two splices per wire but having the connectors and wires cut from the other harness you'll only need one splice per wire. My plan (see picture) was to use non-insulated butt connectors to crimp and hold the wire ends for soldering and cover with heat shrink tubing. These are the supplies I have, the butt connectors, wire and heat shrink tubing if you need this stuff.

Volvo wiring harness
https://parts.volvocarsannapolis.com.../30651188.html

[Xfingers]

huh, that connection doesn't look like it's gonna mate up too well with my Equi harness. My Vida shows volvo harness 30713954 for 05-07 XC70s instead of 30651188 like the link you provided but there's no reason to think the two connections wouldn't be the same. I guess its option 2. Thanks for the offer, FirstVolvo, let me look into this wire splicing. I guess it's this soldering I have no experience in. That pic is great, though. Are those first two pieces already soldered and then you cover with the black shrink wrap? Or does solder still need to be added? Lemme do some research and I'll get back at you!

[FirstVolvo]

Sequence from bottom to top, wires crimped in connector ready for solder, middle shows wires soldered in connector, top is a soldered connection covered in heat shrink. Soldering wires is not difficult with a decent soldering iron, just be sure the wire and connector are clean and hot enough. Heat the wire and connector and when the solder melts when touching the connector/wire junction (not the solder iron tip) you'll have a good solder joint.

[Xfingers]

I've got some experience soldering copper tubing with a torch. I'll need to pick up a solder gun and a heat gun for the shrink wrap (some people use a lighter?). So if the wiring of 2 of the 3 linear solenoids needs to be lengthened, then that's 4 butt joints I'll need to solder and shrink wrap. Now, it seems that Brett San Diego extended his wires using butt connections WITHOUT solder and still had success so maybe the perfect application of solder is not critical if using butt connectors? Also, I'm thinking to do the wire splices correctly the entire harness should be detached and removed from the vehicle completely? If that's the case, then maybe I'll just eat the cost and buy a new wiring harness since either option will require a full wiring harness reinstall.

The fate of my car (and the entire free world?) is hanging in the balance, so I want to give this repair every chance to succeed. Buying a new harness would remove the variable of my untested wire-splicing skills from the equation. I do have VIDA/DiCE so I guess I could check my work by looking at the current readout of the solenoids and activate them to check their function. Still, if the shifting isn't improved after the VB replacement, my XC70 is probably headed for that Great Junkyard in the Sky. I don't want to have a little voice in the back of my head asking, "Did you screw up the splices?"

The 2009 Equinox harness is due in the mail. I want to take a look at that and then I'll probly make a decision. Thanks everyone for your help!