V70 T5 Tranny Troubles

[01_Nautic_V70]

01_Nautic_V70 asked: "When the unit was running/warming up, did it have a whining sound from the transmission area?"

When it was running/warming up this weekend, no, it did NOT have that sound. However, shortly before I was unable to drive it a few weeks ago it DID. What do you make of it???

That's not good. Spending money on solenoids, additives or valve bodies won't touch that problem, so I'd save the dollars.

The filter is clogged, and the transmission fluid pump is starved. As an automatic transmission is a hydraulically operated machine, that pump starving means nothing happens no matter how pristine the valve body is.

There are three (four) ways to handle this:

First and least expensive is the MVS Forum documented "Precopster Super Awesome Aussie Way to Fix It" Essentially, it is drilling a hole under the filter (the filters on these transmissions are not serviceable without transmission removal and disassembly). This will likely run you about $100-150 in new fluids, a die set and RTV sealant. Plus anxiety as you drill into the bellhousing of your beloved wagon.

Second and mid-expensive is the "hey, it works for awhile" method of removing the transmission, opening it up, replacing the filter and seeing if something else is broken in there, then fixing that and putting it all back in. I did this, and it ran about $300-400 plus anxiety as your whole garage is crowded with dismembered Volvo parts waiting to be cleaned and put back in. The results were not great. I found a cracked pressure plate that could not be purchased new, so I had it welded. I found spun bushings that could be replaced, so I bought new. I lovingly rebuilt the whole thing on my workbench over the course of a week. I put it all back in over the next week. It ran. Okayish. For a year. Which brings me to...

Third and more expensive is the "Let's put another transmission in this sweet wagon" method. This has two ways to go. I chose the cheap route and purchased a lowish miles transmission from a 2002 S60. That was $500, delivered to my driveway (in the rain, by a guy in a van, at 1AM) I had another $350 or so in fluids and sundry parts to put in. $850 and a week later, I have a daily driver that shifts wonderfully. Does it have another 50,000 miles in it? Certainly. 100,000? Gosh, I hope so.

The most expensive route is "Wait, what if the transmission being put in was professionally rebuilt by actual professionals" method. It's effectively the same as the method above, except that the transmission is in great condition and painted all nice and gunmetal grey. Cool. The rebuilt transmission is going to be in the $3,000 range, shipped to you (presumably during normal business hours.)

Pour a drink. Do some thinking. Stare at that V70 T5 and think how cool it'd be if you could daily drive it for the next decade. It's 17 years old. If you keep it purring for a decade, you've got a bona fide classic car and will be getting plenty of nostalgia street cred.

Keep us posted on how it goes.

[01_Nautic_V70]

Here's the dreaded filter in question, all gunked up.

And here's the pump that isn't pumping. The good news is that the pump doesn't break due to low flow, it just doesn't pump. so at least it won't need replacement.

Here's what that filter is supposed to look like.

And here's where that filter goes, all tucked up in an open transmission.

[SuperHerman]

Brenda: Your transmission most likely has one of two problems. You have to figure out which one it has. It is known the car has an SLU trouble code. Here you need to dig deeper to choose the correct path needed to solve the issue.

Scenario 1a: The SLU code is caused by a sticking SLU solenoid. A drain and fill or flush may rectify this problem, adding a detergent with the fluid change could aide the process. All of this information has been provided already.

Scenario 1b: The SLU solenoid is starting to fail and working intermittently. They do go bad. Nothing will solve this issue short of changing it. Maybe it is an electical connection harness issue, but without opening the valve body one cannot tell. Although here having a scanner on the car while operating would reveal more definitive information as the computer would provide information of the SLU solenoid behavior.

For Scenario 1a and b - the problem is in the valve body. Repairs range from fluid change to valve body rebuild and this has all been discussed. Transmission does not need to be removed from car and repair solutions not as difficult as transmission removal.

Scenario 2: The car's transmission filter is clogged. Under this scenario the options are drilling a hole in the transmission, installing a used transmission to rebuilding the transmission - in order of cost.

01_Nautic_v70 and precopster have given you the information you need here. Rereading all the posts their extremely important questions don't appear to be addressed at the level their importance warrant. To fully address their concerns you need to drive the car and listen for the "whine" they state will happen as the transmission oil pump starts to starve from lack of fluid due to a restriction caused by a clogged transmission filter. I have failed to consider this.

Backing up I will try to explain the issue as I understand it - hopefully it will provide you some guidance. The transmission fluid is dirty (or was dirty under prior ownership and said owner tried to solve the problem by a drain and flush - this fix worked for sometime, but never solved the clogging filter fully) and the transmission has particles floating around. A good deal of these particles are covering the transmission filter and permanently stuck to it. Very little fluid can pass through the filter. When the car is off some of these particles fall back down and when restarted some fluid can pass the filter for a short period of time. As the transmission oil pump starts up during operation the pump sucks the fluid up and starts to circulate it and more particles hit the screen and fluid flow is severely restricted to the point almost nothing gets through. The transmission is designed so that the flow of the transmission fluid always passes the filter, removing debris from the fluid, to protect the valve body and the rest of the transmission. When the fluid flow becomes restricted a whine is now heard, the vehicle may not move, car codes or shifting becomes erratic and the car starts to slam and buck as the solenoids lack the fluid needed to properly operate shifting. The problem is most likely a clogged filter.

[These particles could be normal clutch material or parts from a failing mechanical component - my brother had a Toyota Camry with a failing component that was shredding metal - the Camry would work for a bit - but once the filter became obstructed as the metal was sucked back into the filter (it would fall down under zero pressure) the Camry would stop moving. I mention this because it is a case where actual physical damage rather than normal wear and tear was the route of the clogging. That is why I suggested when you drain the fluid you take a look for metal sparkle in the drained transmission oil. Under this scenario a used or rebuilt is the only real option.]

You need to focus on the whine and if it is there - this will tell you which of the two scenarios you have with greater certainty.

[firstv70volvo]

Assuming the transmission filter screen is clogged, restricting fluid flow and causing a transmission pump whine here’s something I would try if it were my transmission. I would try to backflush the clogged screen. There is access to the pump suction port after removing a small cover plate on the lower left of the valve body. This suction port provides access to top side of the filter screen.

With the cover plate removed I would pump clean transmission fluid into the suction port to backflush the filter. Have the transmission drain plug removed and using a hand pump for ATF filling pump fluid into the port using a hose through a small plate to seal the port opening and create some pressure in the port. If the filter is clogged with particles I would expect you would see the crud coming from the filter and in the fluid coming out of the drain plug. It wouldn’t cost much to do this, just the fluid for flushing and the labor to get to the valve body. I haven't done this myself but the idea came to me when reading that these filter screens can sometimes become clogged and knowing there is access to the topside of the filter through the valve body cover plate.

This won’t solve internal damage to the transmission or problems with the valve body but if the filter is clogged this may help.

It might be a good idea to have a Volvo valve body gasket kit on hand in case the cover plate gasket gets damaged.

Volvo valve body gasket kit, Volvo part number 274470

pump suction access cover plate.jpg (98.11 KiB) Viewed 3404 times

[SuperHerman]

firstv70volvo - excellent information. I did not know that. I would like to hear from 01_Nautic_v70 and precopster to see if they have tried this - and if so their success.

Brenda: If you do have a whine, then I would try this solution first (if the transmission oil does not have metal sparkle), although the valve body cover will have to come off. For the gasket, the valve body cover is usually sealed with RTV, but a gasket makes the process a whole lot easier. You can use a gasket from a Nissan Maxima that uses the same transmission. Do not recall the years - do a little digging. Most auto stores sell the gasket.

[SuperHerman]

Here is the write up I used when I did my valve body work. I did not use an engine brace, rather I supported the engine with a jack and wood block on the engine oil pan. Engine needs to be supported as part of the subframe is being dropped. The second time I did it I skipped a few steps that made things quicker. It is a good starting point to see what is required. You don't have to take the valve body off, just the valve cover and the plate he points out, if you try firstv70volvo's back flush method.

http://www.volvoxc.com/0/resources/how- ... -Notes.pdf

[01_Nautic_V70]

It seems possible to backflush the filter through that port, though I don't know of anyone here successfully doing so.

That port, specifically the opening on the left as you are facing the valve body, does indeed go back to pump suction (through a pretty convoluted path)

Transmission with Valve Body Removed.jpg (137.58 KiB) Viewed 3312 times

As these casting photos show, only the left port should be used for backflush, the right port goes to the pressure regulator in the valve body.

Mid Casting.jpg (227.16 KiB) Viewed 3312 times

If you could actually pressurize that port with ATF, the fluid would move into the gear pump and be pushed down into the filter.

The O-ringed connection below is where the pump seats on the filter itself.

The good news is, the "stuff" coming through that filter falls out of the filter pickup in the area of the drain plug in the middle of this photo.

What remains utterly unknown is how effective this would be. Will the fluid flush the whole screen clean and get all the gunk out? Or will it flush a square inch of the screen clean and then, because fluid seeks the path of least resistance, the bulk of the gunk remains untouched? My guess here is that high volume, low pressure is the best approach to getting the fluid to backflush that filter rather than a high pressure flush. HVLP may be a real struggle given the small port and the torturous path the fluid must pass through.

TL;DR It MAY work, but it is not known.

[abscate]

Awesome photos and info. It makes me want to run out and buy an AT...

[01_Nautic_V70]

Awesome photos and info. It makes me want to run out and buy an AT...

Fight that urge. If the rest of the family could drive a manual AND if I could find a T5M around me, this one wouldn't be an auto.

[firstv70volvo]

It seems possible to backflush the filter through that port, though I don't know of anyone here successfully doing so.

That port, specifically the opening on the left as you are facing the valve body, does indeed go back to pump suction (through a pretty convoluted path)
Transmission with Valve Body Removed.jpg

As these casting photos show, only the left port should be used for backflush, the right port goes to the pressure regulator in the valve body.
Mid Casting.jpg

If you could actually pressurize that port with ATF, the fluid would move into the gear pump and be pushed down into the filter.
Pump Internals Annotated.jpg

The O-ringed connection below is where the pump seats on the filter itself.
IMG_1870.JPG

The good news is, the "stuff" coming through that filter falls out of the filter pickup in the area of the drain plug in the middle of this photo.
IMG_1917.JPG

What remains utterly unknown is how effective this would be. Will the fluid flush the whole screen clean and get all the gunk out? Or will it flush a square inch of the screen clean and then, because fluid seeks the path of least resistance, the bulk of the gunk remains untouched? My guess here is that high volume, low pressure is the best approach to getting the fluid to backflush that filter rather than a high pressure flush. HVLP may be a real struggle given the small port and the torturous path the fluid must pass through.

TL;DR It MAY work, but it is not known.

Nautic V70, you have a good understanding of the pump suction path and yes it's somewhat convoluted but I think the filter could be cleaned well with a combination of transmission cleaner, such as the lubegard kooler kleen product, maybe some low PSI compressed air and a final flush with ATF. A small plate with a hose hole would be needed to seal the port for the fluid and air input and I think you could get some idea of the effectiveness of the filter cleaning by the flow of what's coming out of the drain plug vs what's being pumped in, how much and has fast is the fluid is coming out in addition to the amount of crud that's come out. If I ever have to service the valve body again I plan on doing a backflush of the filter.

http://www.lubegard.com/~/C-184/Kooler+ ... ed+Formula