AW55-50SN woes-easy to repair? Topic is solved

[vtl]

External filter gets only a part of ATF that is circulating inside the transmission, by design. All that escaped gunk will be flowing through the valve body, that's why transmission is dying later. The colder the ATF, the higher is the pressure, the lesser amount of ATF is diverted by the ball valve to the cooler.

Just be aware.

[renns]

Hopefully the repeated flushings via dipstick hole will clean things out well enough. Time will tell.

[renns]

The job is now complete, and the car is back on the road, with 100 km of driving so far. It shifts fine when warm, but has does still have some random flares when cold. The horrible transmission howling sound on startup is now completely gone. I had to reset transmission codes twice in the first couple km's of driving, but no further codes have been set since. Hopefully this 'fix' buys us enough time to source a suitable replacement vehicle. Many thanks to those adventurous souls that posted this information.

[renns]

A quick update: The odometer has now rolled past 700 km since the 'fix' described in this thread was applied. The transmission has settled down nicely, with flare issues gone. Considering the car was not drive-able, and destined for the recyclers a couple weeks ago, the transformation is amazing.

[precopster]

I missed this journey as you posted. Well done!

[renns]

Well over a thousand km's now, and am starting to have faith in the old girl once again. We've been shopping for newer replacements (Venza, Murano, RX-350...), but the XC70 is hard to replace - Luxury, loads of interior space, 3500 lb towing capacity, AWD...

[renns]

I thought I'd post a quick follow-up. The transmission after 'hack' continued to function. It did go in to limp mode twice more during the 2500 km's I put on the car. Fortunately, simply clearing the code with my phone returned the transmission to proper shift operation again, with minimal fuss. That said, I didn't trust the car for some of the long-distance travel we have scheduled in the months ahead. I put the car up for sale, clearly stating it needed a transmission replacement. It was sold the first day! Interestingly, the buyer is planning to strip the car, and ship good parts to Africa. He purchased an XC90 the same day that met the same fate.
A Toyota Venza has been purchased as a replacement. I'm sure it will serve us well, but I will truly miss the XC70.

[abscate]

The worst part of getting rid of a car on 'suspicions' is when you sell it local, and see it around town 10 years later, still looking great, with 600,000 km on it!

[vtl]

The worst part of getting rid of a car on 'suspicions' is when you sell it local, and see it around town 10 years later, still looking great, with 600,000 km on it!

P2 is the last Volvo that is able to last that long. Wife's P3 (2016 XC60) is starting to fall apart. Everything I take apart is made of plastic or rust-prone metal where in P2 it is a spotless alloy. Material quality-wise Volvo is like Toyota now.

[evilcowboy420]

I would like to say thank you to the OP of this thread and everyone who did this before me. I just did this because I had 0 pressure come out of the lines when I check and had the no move condition. I had did the valve body and solenoids and still nothing. As a last ditch effort I tried this modification and boom car moves.

It was slow at first but then the gears started shifting correctly. I have driven 15 miles and filled with gas and it made it with only a few shift flares which I expected because of the learning process and seeing a new line pressure. Reverse was back almost instantly but the forward gears did take a second to kick in to an acceptable change. It was flaring around the 3 grand mark for only a few times. As with the OP my 1-2 gear feels soft but I expect it to be better once it learns.

The feel of the shifting is much better as well.

I drilled in exactly the same spot as both the OP and the guy with the SAAB. I drilled to 5/16th and tapped for a 3/8-16 thread and used a simple scratch awl to poke through the filter then I took a skinny long screw driver and widened the hole in the filter and started moving it around until I was satisfied it destroyed the screen. I used a hex bolt with an O ring to seal.

Now all i have to do is get a nice external filter and I will probably filter the fluid in my transmission funnel with a screen in it and reuse again since its new fluid from the valve body change and solenoid work I did.

Oh and this transmission was in a 2008 Pontiac Torrent.

Again I am extremely grateful to the guys who did the work and brainstormed the idea. Thank all of you for your contribution.