[V50_M66]

I’ll start this one with a little backstory. I bought my 04 XC70 a little over a year ago with roughly 187k miles on it for cheap because the transmission would shift like hot garbage after it was warmed up and was basically undriveable, but was mostly fine for the ~15 minutes of driving that it was still cold. Previous owner thought it needed a new trans, hence the asking price.

I immediately got to work fixing it. Thanks to some research on here and on other Volvo forums, I found that worn out solenoids in the trans were causing my issues. I pulled the cover (kind of a pain, but doable. A forum post that I’ve since lost and the VIDA instructions were key) and replaced the three main solenoids. Sealed it back up, put the car back together, drained and refilled the fluid to the same level with Volvo Genuine fluid (verified correct level on dipstick), reset the fluid counters with VIDA, and took it for a drive. It shifted kinda rough at first as it got used to the new solenoids, but after a week of varied driving, it started shifting pretty much exactly like my old 05 XC90 with the same drivetrain. Thought it was fixed, drove it over 10k miles no issues. Earlier this year when it was still cold outside it started shifting like crap when it was cold. Super rough shifts and the occasional flare, and delayed drive and reverse engagement. Once it warmed up, it drove fine. If I drove it in manual mode, it was way better when cold, so I’d drive it for like 5 minutes in manual mode and then it’d be fine. Checked the fluid level and it was spot on, and didn’t look very dark. Figured it was a quirk of the trans having 200k on it and called it good enough, since it was fine unless it was super cold.

Well, as it’s gotten warmer, driving it cold isn’t as bad, but still not great. Still the occasional delayed drive and reverse engagement that goes away when warm. However, it isn’t shifting great when it’s warm either. 1-2 is pretty hard sometimes, 2-3 flares somewhat (although not always), 3-4 usually flares, and 4-5 is still good. Mostly the same in manual mode, but not as bad, especially since I can correct for it with changing throttle. Downshifts in manual mode don’t really engage unless I get the revs up usually (when slowing down). When giving it a bunch of gas and downshifting, as if I was trying to pass someone (in both manual and auto), it takes a good second or two to fully engage, especially the 3-2 and 4-3. 5-4 is fine. Almost like it’s in limbo between gears. Also, I’ve noticed the torque converter lockup works fine on the gas, but you let off and the revs drop. Give it gas again and it goes up and then comes back down as the converter locks again. Let off again, same deal. Rinse and repeat. I don’t remember it doing that last fall.

I can get a video of it if needed.

Is there anything I can do to prolong the life of my trans? It doesn’t slip, just shifting isn’t great. I’d love to get at least a few more thousand miles out of it before I either throw a junkyard AW55 in it or tackle an M66 swap (which would be awesome, but not in the budget currently unless so can get parts cheap). I also don’t really have the time for another project right now (my V50 is currently taking up my lift with its own issues), and it’s my daily, so prolonging the original trans’ life is ideal.

Would changing the fluid help? How about running the adaptation with VIDA? I’ve already done the solenoids, so it’s unlikely they are the problem again, right? Especially since it’s different symptoms. At least I would think.
Where should I begin?
Thanks in advance

 

[ZZZZZZZ]

Subscribed. Hoping to read what the solutions are.

 

[Georgeandkira]

Get a pressure testing kit and the data chart. Your woes sound like they could be pressure related.
Harbor Freight has a basic one so look at it to see if it's OK or if you'd rather buy a "better tool".
Maybe AZ has one in their "tool loaner" program.

 

[volvogod]

Do you have any TCM codes? Dump in a can of Seafoam transmission conditioner, can't hurt. Any trash that was in the oil is probably inside the valve body and can not be flushed out. A new valve body probably will not help. The transmission will probably fail in time. SW may or may not help. There is SW available for your car. Look thru the list for year, model and symptoms.

 

[zak]

Servo cover, while you're in there put in a longer GM pin.

If that doesn't get it, time for the GM valvebody swap (better solenoids than the aftermarket ones). No ones ttried it yet, but with the valvebody off it should be possible to carefullly backflush the filter using Seafoam or more like BG transmission cleaner, then backflush the screen with some fresh fluid, letting all of this drain out the bottom.

for the latter see firstv70's post here

V70 T5 Tranny Troubles - Page 4

New MVS member here - not too familiar with Volvo’s though I have a bit of car knowledge overall. My GF is on her 5th Volvo (over the past thirty years). Her ou

www.matthewsvolvosite.com

or zak's post here:

AW55-50SN woes-easy to repair? - Page 23

A second observation after reading this thread: In this post zaq (no relation) discusses using the drilled in port to simply vacuum off the screen: https://www.

www.matthewsvolvosite.com

or

Repairing a AW55-50SN Transmission in a 2001 V70

On a C70, I too figured out that using air to clear the filter works. Then once driving it clogged again. I gave up after that and swapped the transmission out. I never thought about finding a solvent to cure the issue.

www.matthewsvolvosite.com

 

[V50_M66]

Get a pressure testing kit and the data chart. Your woes sound like they could be pressure related.
Harbor Freight has a basic one so look at it to see if it's OK or if you'd rather buy a "better tool".
Maybe AZ has one in their "tool loaner" program.

Agreed that it seems like a pressure issue. Should be pretty easy to test - just hook into the trans cooler lines right? What should the pressure values be?

Do you have any TCM codes? Dump in a can of Seafoam transmission conditioner, can't hurt. Any trash that was in the oil is probably inside the valve body and can not be flushed out. A new valve body probably will not help. The transmission will probably fail in time. SW may or may not help. There is SW available for your car. Look thru the list for year, model and symptoms.

There aren’t any lights on the dash (except for an ABS light that I know 100% is a cracked tone ring on the front passenger wheel, which came after the trans issues started so it’s not related. I’m waiting for a new one to ship and then I’ll get that fixed). I haven’t had time to scan it with VIDA yet but I’ll do that as soon as I can. Can I do the SW updates myself with VIDA or do I have to go to the dealer to get that done?

Servo cover, while you're in there put in a longer GM pin.

If that doesn't get it, time for the GM valvebody swap (better solenoids than the aftermarket ones). No ones ttried it yet, but with the valvebody off it should be possible to carefullly backflush the filter using Seafoam or more like BG transmission cleaner, then backflush the screen with some fresh fluid, letting all of this drain out the bottom.

for the latter see firstv70's post here

V70 T5 Tranny Troubles - Page 4

New MVS member here - not too familiar with Volvo’s though I have a bit of car knowledge overall. My GF is on her 5th Volvo (over the past thirty years). Her ou

www.matthewsvolvosite.com

or zak's post here:

AW55-50SN woes-easy to repair? - Page 23

A second observation after reading this thread: In this post zaq (no relation) discusses using the drilled in port to simply vacuum off the screen: https://www.

www.matthewsvolvosite.com

or

Repairing a AW55-50SN Transmission in a 2001 V70

On a C70, I too figured out that using air to clear the filter works. Then once driving it clogged again. I gave up after that and swapped the transmission out. I never thought about finding a solvent to cure the issue.

www.matthewsvolvosite.com

Interesting, thanks for the info. Funny you mention that - I have an 07 Saab 9-3 2.0T with the same 5 speed (just the GM/Saturn/Saab version) and it seems to behave much better, even before the trans on my XC started misbehaving.
Where would I get that GM pin? When you say servo cover, should I replace the cover, or just take it off again to inspect and replace stuff?
Putting in a whole GM valve body and solenoids wouldn’t confuse the TCU or anything else? It’s just plug and play?
Oh and thanks for the articles and threads. Gonna give those a thorough read.

 

[dcswan]

I’ll start this one with a little backstory. I bought my 04 XC70 a little over a year ago with roughly 187k miles on it for cheap because the transmission would shift like hot garbage after it was warmed up and was basically undriveable, but was mostly fine for the ~15 minutes of driving that it was still cold. Previous owner thought it needed a new trans, hence the asking price.

I immediately got to work fixing it. Thanks to some research on here and on other Volvo forums, I found that worn out solenoids in the trans were causing my issues. I pulled the cover (kind of a pain, but doable. A forum post that I’ve since lost and the VIDA instructions were key) and replaced the three main solenoids. Sealed it back up, put the car back together, drained and refilled the fluid to the same level with Volvo Genuine fluid (verified correct level on dipstick), reset the fluid counters with VIDA, and took it for a drive. It shifted kinda rough at first as it got used to the new solenoids, but after a week of varied driving, it started shifting pretty much exactly like my old 05 XC90 with the same drivetrain. Thought it was fixed, drove it over 10k miles no issues. Earlier this year when it was still cold outside it started shifting like crap when it was cold. Super rough shifts and the occasional flare, and delayed drive and reverse engagement. Once it warmed up, it drove fine. If I drove it in manual mode, it was way better when cold, so I’d drive it for like 5 minutes in manual mode and then it’d be fine. Checked the fluid level and it was spot on, and didn’t look very dark. Figured it was a quirk of the trans having 200k on it and called it good enough, since it was fine unless it was super cold.

Well, as it’s gotten warmer, driving it cold isn’t as bad, but still not great. Still the occasional delayed drive and reverse engagement that goes away when warm. However, it isn’t shifting great when it’s warm either. 1-2 is pretty hard sometimes, 2-3 flares somewhat (although not always), 3-4 usually flares, and 4-5 is still good. Mostly the same in manual mode, but not as bad, especially since I can correct for it with changing throttle. Downshifts in manual mode don’t really engage unless I get the revs up usually (when slowing down). When giving it a bunch of gas and downshifting, as if I was trying to pass someone (in both manual and auto), it takes a good second or two to fully engage, especially the 3-2 and 4-3. 5-4 is fine. Almost like it’s in limbo between gears. Also, I’ve noticed the torque converter lockup works fine on the gas, but you let off and the revs drop. Give it gas again and it goes up and then comes back down as the converter locks again. Let off again, same deal. Rinse and repeat. I don’t remember it doing that last fall.

I can get a video of it if needed.

Is there anything I can do to prolong the life of my trans? It doesn’t slip, just shifting isn’t great. I’d love to get at least a few more thousand miles out of it before I either throw a junkyard AW55 in it or tackle an M66 swap (which would be awesome, but not in the budget currently unless so can get parts cheap). I also don’t really have the time for another project right now (my V50 is currently taking up my lift with its own issues), and it’s my daily, so prolonging the original trans’ life is ideal.

Would changing the fluid help? How about running the adaptation with VIDA? I’ve already done the solenoids, so it’s unlikely they are the problem again, right? Especially since it’s different symptoms. At least I would think.
Where should I begin?
Thanks in advance

Based on your symptoms a valve body fix or replacement will likely help you out. It's not only the solenoids that cause problems, a worn valve body can mean the fluid pressure shared by the 3 linear solenoids isn't what it should be and you'll get shifting problems like you're having, especially differences in shift quality between cold and hot operation.
Sonnax make a Zip kit for a little over $200. I haven't used the Sonnax kit but it looks like a good quality kit.
Sonnax Zip Kit® - AW55-50SN-ZIP

Or, an AC Delco valve body for ~ $500 (made by Aisin) and you'll have to do a couple of minor changes to make it work your Volvo, I have replaced (5 years ago) the valve body with the AC Delco part and it works great. See my notes on what to do to make it compatible.
Amazon.com: GM Genuine Parts 24228787 Automatic Transmission Control Valve Body with Gaskets and Seals : Automotive

As long as your transmission isn't slipping and in good shape overall a valve body fix should help with shift quality problems.

 

[V50_M66]

Based on your symptoms a valve body fix or replacement will likely help you out. It's not only the solenoids that cause problems, a worn valve body can mean the fluid pressure shared by the 3 linear solenoids isn't what it should be and you'll get shifting problems like you're having, especially differences in shift quality between cold and hot operation.
Sonnax make a Zip kit for a little over $200. I haven't used the Sonnax kit but it looks like a good quality kit.
Sonnax Zip Kit® - AW55-50SN-ZIP

Or, an AC Delco valve body for ~ $500 (made by Aisin) and you'll have to do a couple of minor changes to make it work your Volvo, I have replaced (5 years ago) the valve body with the AC Delco part and it works great. See my notes on what to do to make it compatible.
Amazon.com: GM Genuine Parts 24228787 Automatic Transmission Control Valve Body with Gaskets and Seals : Automotive

As long as your transmission isn't slipping and in good shape overall a valve body fix should help with shift quality problems.

It’s not slipping, just shifts aren’t the best. Not sure what kind of shape the trans is in. The previous owner changed the fluid in hopes it would fix it originally so I don’t know what the fluid looked like before

 

[Brett San Diego]

My money's on a new valve body needed. It's not just the servo pistons that wear. The valve body itself wears. It's aluminum. I put the AC Delco unit in my 2002 XC70, and it's been good since.

See this thread over on the XC forum (remove the spaces). Pretty much everything you need to know.

https://www . volvoxc . com/forums/showthread.php?29347

The pdf file attached above is very good, too.

Brett

 

[V50_M66]

When I get a chance over the weekend I think I’ll change the fluid again if I can find some, reset the counters, and do the adaptation. I never did the adaptation when I put the new solenoids in (I’ll do it tomorrow type deal - just never got around to it) so I’ll try that and hopefully it helps

 

[dcswan]

It’s not slipping, just shifts aren’t the best. Not sure what kind of shape the trans is in. The previous owner changed the fluid in hopes it would fix it originally so I don’t know what the fluid looked like before

Not slipping is key as any slipping will ruin things internally in a short amount of time. The linear solenoids SLT and SLS are most important for shift quality and garage shifts and there are many wear areas in the valve body that can affect the regulated fluid supply to these solenoids. Because you have a delay engagement for both D and R, which are controlled by different linear solenoids for the garage shifts I think there's a problem with the regulated fluid supply to the linear solenoids. The Sonnax Zip kit addresses all the regulated fluid supplies in the VB and should be a good fix. If you can afford the additional $300 for the valve body it gives you an all new valve body and solenoids. I have over 50K miles on the replaced valve body now and still working like new.

 

[Brett San Diego]

When I get a chance over the weekend I think I’ll change the fluid again if I can find some, reset the counters, and do the adaptation. I never did the adaptation when I put the new solenoids in (I’ll do it tomorrow type deal - just never got around to it) so I’ll try that and hopefully it helps

Don't waste money on more fluid. It's not cheap. Your money is better spent on a new valve body. Change the fluid when you put in the new valve body.

Brett

 

[V50_M66]

Don't waste money on more fluid. It's not cheap. Your money is better spent on a new valve body. Change the fluid when you put in the new valve body.

Brett

I hear you. Honestly just don’t really feel like doing that job again until it gets really bad, and I’m hesitant because I’m concerned it’s actually a clogged filter or a combo of the two.
I can get some Toyota T-IV (exact same J3309 stuff as the Volvo fluid) for pretty cheap so it’s not that expensive. I might just do the adaptation if I don’t have extra fluid laying around.
Probably just gonna start with adaptation with the current fluid and go from there depending on how well that works.

 

[Brett San Diego]

I don't pretend to be a transmission tech who's seen hundreds of these transmissions through the years, but anecdotally on forums, I don't see cases where someone has said they replaced their valve body and that didn't solve the problem and that they had to go back in and take measures to clear the filter. So, FWIW, I don't think the filter is your concern here.

Brett

 

[V50_M66]

I don't pretend to be a transmission tech who's seen hundreds of these transmissions through the years, but anecdotally on forums, I don't see cases where someone has said they replaced their valve body and that didn't solve the problem and that they had to go back in and take measures to clear the filter. So, FWIW, I don't think the filter is your concern here.

Brett

Thanks for that. Would valve body issues also cause the odd torque converter lockup behavior? That combined with the other symptoms and the articles/threads linked above by others about clogged filters causing issues has me concerned that I’m gonna do all this work and spend all this money for that to not be the issue. Would almost rather just try the adaptation (free!) and hope I can get another year or so out of it and save the money for an M66 swap down the road.

 

[Brett San Diego]

Thanks for that. Would valve body issues also cause the odd torque converter lockup behavior? That combined with the other symptoms and the articles/threads linked above by others about clogged filters causing issues has me concerned that I’m gonna do all this work and spend all this money for that to not be the issue. Would almost rather just try the adaptation (free!) and hope I can get another year or so out of it and save the money for an M66 swap down the road.

If you're planning a manual swap, I'd save your money for that. I don't think there's a cheap short-term repair here, but I'm not a transmission tech. So, you can take my opinion for what it's worth.

On the torque converter lockup... maybe? I don't know. Maintaining clutch engagement is all about maintaining the proper fluid pressure. I would think that lower rpm would lead to lower pressure being available to all valve body circuits. So, when rpm's drop you lose pressure, but when they go up, you get the pressure back. If your valve body is worn such that the required pressure in the lockup circuit can't be maintained when the oil pressure drops at low rpm, then yeah, it makes complete sense. But, I don't know enough about the actual fluid circuits to answer that question definitively.

The transmission computer uses a variety of inputs to decide whether to lock the converter. rpm is probably one of them. Maybe it's programmed to unlock at low rpm. Again, I don't know.

Brett

 

[V50_M66]

If you're planning a manual swap, I'd save your money for that. I don't think there's a cheap short-term repair here, but I'm not a transmission tech. So, you can take my opinion for what it's worth.

On the torque converter lockup... maybe? I don't know. Maintaining clutch engagement is all about maintaining the proper fluid pressure. I would think that lower rpm would lead to lower pressure being available to all valve body circuits. So, when rpm's drop you lose pressure, but when they go up, you get the pressure back. If your valve body is worn such that the required pressure in the lockup circuit can't be maintained when the oil pressure drops at low rpm, then yeah, it makes complete sense. But, I don't know enough about the actual fluid circuits to answer that question definitively.

The transmission computer uses a variety of inputs to decide whether to lock the converter. rpm is probably one of them. Maybe it's programmed to unlock at low rpm. Again, I don't know.

Brett

Yeah it’s odd. It locks when you are on the gas like normal, but unlocks off the gas. Give it gas again, and the revs go up, and then the converter locks again and drags them down. Over and over. Even at like 90 mph in top gear (~3k rpm) when it should be consistently locked. I think I’ll save for a manual swap. Kinda sick of mediocre autos anyway.

 

[Georgeandkira]

"Agreed that it seems like a pressure issue. Should be pretty easy to test - just hook into the trans cooler lines right? What should the pressure values be?

Pressures and such are what's on the data sheet. I want to guess ~150psi.

Do at least one drain & fill as you want to see how foul the fluid is. If it's real disgusting, consider several to dilute the dirt before replacing to the valve body. Get 4 quarts of Toyota T-IV fluid for your your first D&F. Then, if it's foul you can order more cheaply from an online source. I cleansed several of these AW55-50 Volvo transmissions using Valvoline MaxLife Dex/Merc LV. The LV makes it usable in these units. I've used gallons of the Toyota T-IV, real 3309, Wolf's Head Super Universal synthetic...all with success. I also use LubeGard red as it smoothed out a balky AW55-50 so I trust it.

Raise the left (driver's side No.America) higher than the right to get more fluid out.

Over the years I used up my stock and when the transmission drain came around on my 2007, I bought a Volvo fluid kit online for reasonable money and now I have no ATF stash. I should check my mileage.

 

[V50_M66]

"Agreed that it seems like a pressure issue. Should be pretty easy to test - just hook into the trans cooler lines right? What should the pressure values be?

Pressures and such are what's on the data sheet. I want to guess ~150psi.

Do at least one drain & fill as you want to see how foul the fluid is. If it's real disgusting, consider several to dilute the dirt before replacing to the valve body. Get 4 quarts of Toyota T-IV fluid for your your first D&F. Then, if it's foul you can order more cheaply from an online source. I cleansed several of these AW55-50 Volvo transmissions using Valvoline MaxLife Dex/Merc LV. The LV makes it usable in these units. I've used gallons of the Toyota T-IV, real 3309, Wolf's Head Super Universal synthetic...all with success. I also use LubeGard red as it smoothed out a balky AW55-50 so I trust it.

Raise the left (driver's side No.America) higher than the right to get more fluid out.

Over the years I used up my stock and when the transmission drain came around on my 2007, I bought a Volvo fluid kit online for reasonable money and now I have no ATF stash. I should check my mileage.

I've checked the fluid with the (buried) dipstick and it's not super dirty. I'll get the adaptation done and go from there.

 

[jschaefer7406]

I've checked the fluid with the (buried) dipstick and it's not super dirty. I'll get the adaptation done and go from there.

That dipstick is a pain in the nads, isn’t it?! 😂

Who thought that was a good idea, when it needs to be checked hot and there’s a zillion degree radiator hose right above it. Not to mention finding a funnel that fits…