Auto box fluid renewal

[Kev0607]

Mr Google says...

"Simply put, when the engine is off, the fluid drains from the torque converter into the pan leading to an incorrect transmission fluid reading. On the other hand, with a running engine, the fluids will be all around the transmission system, including the torque converter. This gives a more accurate fluid-level reading."

So the only way to set the level properly is with the engine running. This allows the fluid throughout the transmission, which won't happen if the engine is off.

[Backinavolvo]

Originally Posted by Andymharrison

That depends on the gearbox, the older ones have a dipstick which is much more sensible, you can leave the airbox in place.

You are right but my advise was for this spa subgroup

[DG97]

Originally Posted by Bonefishblues

Or find your local specialist with one of these machines to do it for you (every c50-60K miles is the typical interval for these 'boxes for the manufacturers who specify them):

https://www.edtautomotive.com/transmission-clean/

It's what our Indy uses, and I had it done on mine at slightly higher miles than yours. Interesting article by him:
https://hortoncars.com/volvo-news/vo...and-solutions/

Sorry to chip in but this is something I’ve wanted to do on my SPA platform S60. I like the recommendation for Horton Cars. Do you know if they deal with the SPA cars often/can the do this procedure on the SPA cars too?

[Kev0607]

Originally Posted by DG97

Sorry to chip in but this is something I’ve wanted to do on my SPA platform S60. I like the recommendation for Horton Cars. Do you know if they deal with the SPA cars often/can the do this procedure on the SPA cars too?

Yes, Horton's are Volvo Specialists. They work on new and old.

[Andymharrison]

Originally Posted by Kev0607

Mr Google says...

"Simply put, when the engine is off, the fluid drains from the torque converter into the pan leading to an incorrect transmission fluid reading. On the other hand, with a running engine, the fluids will be all around the transmission system, including the torque converter. This gives a more accurate fluid-level reading."

So the only way to set the level properly is with the engine running. This allows the fluid throughout the transmission, which won't happen if the engine is off.

Thats sort of what I'd always assumed was going on. I guess it must be a relatively small amount of fluid otherwise you'd be able to drain more from the sump but enough to upset the level readings.

Strangely I've never been too bothered by getting underneath a running car to get to the level plug etc but have always been very wary of shoving my arm down the side of a running engine as you do to get to the dipstick on my old xc90.

[Bonefishblues]

Originally Posted by DG97

Sorry to chip in but this is something I’ve wanted to do on my SPA platform S60. I like the recommendation for Horton Cars. Do you know if they deal with the SPA cars often/can the do this procedure on the SPA cars too?

Yes. It's worth considering a trip down, I'd say, especially if combined with a family visit to Bicester Village or Oxford. Graham's (chap who owns it) loan cars are legendary in their own right. I don't think I've ever had one with less than 200K on it, but they just go on and on.

When I last had my XC70 done in 2021 (IIRC) it was c£300 for the service, which transformed the car. He reckons that the kit changes well in excess of 90% of the fluid, so it's as good as you're going to get.

Hope useful.

[Carabind]

Originally Posted by Carabind

Thank you !

The physical part is fine, and no issue for me
I have a foxwell diagnostic tool , which I’ve used for resetting the service interval and rewinding the rear caliper for brake servicing. I'll check out if it has access to the TCM and report back .

What would happen if you just changed the oil but didn’t interrogate the TCM to reset the fluid counter ?

My Foxwell tool does display the box temp, but nothing visible for resetting any values.
Bonefish , I do whiz up and down the M40, so will contact Hortons for a quote, too.( If they can do it whilst I wait, that will help)

[Kev0607]

Originally Posted by Carabind

My Foxwell tool does display the box temp, but nothing visible for resetting any values.
Bonefish , I do whiz up and down the M40, so will contact Hortons for a quote, too.( If they can do it whilst I wait, that will help)

Resetting the counter isn’t strictly necessary. Setting the level in the transmission is.

Originally Posted by Andymharrison

Thats sort of what I'd always assumed was going on. I guess it must be a relatively small amount of fluid otherwise you'd be able to drain more from the sump but enough to upset the level readings.

Strangely I've never been too bothered by getting underneath a running car to get to the level plug etc but have always been very wary of shoving my arm down the side of a running engine as you do to get to the dipstick on my old xc90.

Depends if the transmission was overfilled or not in the first place. It holds say 3 litres give or take. If you add more than what it holds (which people tend to do when doing a trans service to renew as much fluid as possible), that additional fluid that was added is what should drain out when the car is running to set the level.

[Volvocano]

Of course if you have a couple of big plastic measuring jugs and fill one with the used fluid (after it's cooled) and the other your new fluid - and pour that exact amount back in plus a cap-full for what's stuck lining the jug you won't introduce any new problems - if the fluid was slightly low before it still will be. I actually prefer that method if I'm not operating on a perfectly flat surface. My drive is on a slant so I can't rely on the to-the-book levelling method.

[Bonefishblues]

Originally Posted by Kev0607

Resetting the counter isn’t strictly necessary. Setting the level in the transmission is.

Depends if the transmission was overfilled or not in the first place. It holds say 3 litres give or take. If you add more than what it holds (which people tend to do when doing a trans service to renew as much fluid as possible), that additional fluid that was added is what should drain out when the car is running to set the level.

Just for clarity the AW55 and TF80SC have a 'box capacity of 7 litres of ATF, but only c3 litres can be extracted by a drain, hence the multiple drain and fill method used by many. I'm sure that's what you meant, but it reads as if it's the total capacity