auto box transmission flush

[Bonefishblues]

Yes, pretty much that /\/\

Kev, not sure that wholly clean ATF would be, as you put it, 'a shock' to the transmission. What exactly do you mean, given I much prefer to 'shock' mine every 50-60k miles?

[IainG]

Hi

'a shock' to the transmission

Generally this refers to a gearbox with old dirty oil in it will also have pockets of dirt / sediment and possibly some varnish/ gum type deposits around the solenoid valves.
The new oil will have a "new package of additives" and detergents .
If you replace all the oil with new, the detergents might clean/ relaease the dirt all at once and can end up blocking hydraulic ways.
If you do a 3 Ltr change at a time all the deposits will clear more slowly and will be held in suspension that will then be reduced with the next 3 Ltr change.
So if you have a gearbox with old dirty oil people seem to have less problems with a partial change.but more frequently.
If you have changed your oil before it gets bad a full change every now and again will probably have less issues.
I am sure if it was my gearbox I would certainly err on the side of caution and at least do a partial change the first time until I see what come out and if there are any negative effects on the box.

Iain.

[Bonefishblues]

So something rather different to a 'shock' to the transmission, rather we're back to doing the changes that Volvo doesn't (arduous use and towing excepted) and the associated fear that if we change too much fluid at once the box won't be able to cope.

When I next speak to the Indy who do my changes (whole change, that is, special machine and all that) I'll ask him if he's ever experienced this issue.

What a stupid state of affairs that this debate is being had - I'm talking to you Volvo.

[Tannaton]

I think in 6 years of being on this forum, I can only recall one instance of someone doing a full transmission flush and the gearbox being worse after that process than before....

[Kev0607]

Originally Posted by Bonefishblues

Yes, pretty much that /\/\

Kev, not sure that wholly clean ATF would be, as you put it, 'a shock' to the transmission. What exactly do you mean, given I much prefer to 'shock' mine every 50-60k miles?

I don't know the condition that the previous owner of my vehicle kept the transmission in... It has nearly 103,000 on the clock full Volvo service history, but I don't know whether he/she ever changed the fluid because its not a service item (Unless used in extreme conditions or towing) & there's no receipts that indicate the job has been done (I purchased it from a non-Volvo garage, not privately). This is why a partial drain/refill of the system (3L at a time) periodically on a higher mileage vehicle particularly is the better option to a whole flush in my opinion, as there's less chance of gunk being removed at once & getting trapped inside the internals of the transmission (Flushing can potentially do this, 'shocking' or causing the transmission to 'play up' for one of a better word).

I've heard & am aware of plenty of stories where flushing gearbox caused issues - These weren't on Volvo's mind, but for this reason, I don't flush a transmission on any vehicle & I don't flush the engine oil either. However, I stick to the principle that there's less of a risk of dislodging gunk/grime that builds up over the years by draining & filling a transmission periodically than flushing one in one go. The original poster has 110,000 on the vehicle in question & has no record of the transmission fluid being changed (Or hasn't indicated so, so presumably it hasn't). In my view, taking the mileage into account, a drain & fill is the best route to take to reduce the chances of dislodging harmful deposits. The garage I brought my car to doesn't do flushing & simply said "It can cause more harm than good, we don't do it". Again, I was advised against the flushing process.

I don't know how much a transmission is for these vehicles, but I imagine it won't be cheap & probably in the thousands bracket. Flushing is not a risk I'd take personally, but if it works for you & you've had no issues with your car, then that's fine. It boils down to personal preference & there's no right or wrong way. What people do with their own cars is their choice - I'm no expert & don't claim to be one either. I'm simply offering my opinion on the job in hand, but ultimately, people can do as they please.

Note, I've said flushing can potentially cause issues. As an example, many Volvo D5 owners are aware the aux belts are a weak point - There's a potential for them to fail prematurely. It might never happen, its something that could happen. The same with flushing a transmission, you might never issues. Potentially though, there's a higher risk of gunk/dirt being dislodged when flushing the transmission in one go than draining & filling 3L over a period of time.

Here's some threads on other forums, with posts that advise against flushing. Although, flushing is recommended by some people too... Its a grey area, but again, its up to individuals what they do with their vehicles. I don't flush mine, nor would I recommend it:

https://forums.swedespeed.com/showth...er-fluid-flush

https://volvoforums.com/forum/volvo-...nge-not-27375/

https://volvoforums.com/forum/volvo-...d-flush-10115/

https://volvoforums.com/forum/volvo-...uid-not-38922/

[Bonefishblues]

Kev, that was clear in your previous posts. You've done a lot of research over the last few weeks since you first started looking for advice, clearly - I know we had some discussions then.

Of course one can find lots of stories on the net. That's the nature of the net. People with issues post, people who don't, don't. As Tannaton states in his recent post though, actual documented cases are few and far between.

I chose to do what I did with a slightly higher mileage car than yours (at 113K miles and 8 y.o.) on the '80 box, going to my usual Indy, and taking his advice (just for others' benefit/info, here's Graham's treatise on the gearbox, he also has an AW55 one on his site):

https://www.hortoncars.co.uk/volvo-n...and-solutions/

Initially we thought we might be in for a valve body change, because the banging hadn't disappeared, but it seems that over the course of the next week or two everything freed up nicely. One can only speculate whether a 3L drain and fill might have made a difference or not, as opposed to this more 'aggressive' approach - term used advisedly to chime with the 'shock' word

Anyhow, that's been my approach running AW55s and now the '80 over the last 9-10 years or so, but everyone will of course make their own judgement as to what's right for them after what I think's been an interesting and useful debate.

[Kev0607]

Yep, I've done a lot of research myself since & recently invested in VIDA also. Thank you for any advice that you may have given at the time, much appreciated. I remember looking at that article from Horton Cars, a very interesting read it was too. I've also had a look on Auto Trader at some of the cars they have for sale & there's some very nice ones at reasonable prices.

Each to their own as they say, there's no right or wrong way as such. It all boils down to personal preference.

[PaddyB]

I've always been an advocate of flushing auto-boxes when changing auto oil. It takes more oil & maybe another filter (if your OCD like me) but I'm interested to hear why it's considered to be bad practice.
It's been a while since I've been into cars & the accepted wisdom is always in flux - I'm just interested in learning.

[Kev0607]

Originally Posted by PaddyB

I've always been an advocate of flushing auto-boxes when changing auto oil. It takes more oil & maybe another filter (if your OCD like me) but I'm interested to hear why it's considered to be bad practice.
It's been a while since I've been into cars & the accepted wisdom is always in flux - I'm just interested in learning.

It all boils down to personal preference as to how an individual does a job...There's no right or wrong way as such & I'm not implying that anyone that flushes their transmission is wrong for doing it.

From what I've researched & have been told, it seems that flushing a transmission is a bit harsher so to speak. Therefore, there's a chance of gunk/grime that's built up over the years being dislodged & getting trapped inside the internals of the transmission, which can lead to problems. I suppose another example would be flushing an engine, many recommend it & many don't.

I don't like flushing a transmission for this reason personally & have been advised against it by garages. Do as you please though, I'm not an expert.