6L80 (V8 Trans) experiences after power flush?

[Dart77]

I was wondering if any V8 auto owners (6L80 trans) have found any dramas with their auto after having a transmission flush done? Have seen a few YT videos and heard of transmission places being reluctant to do the full flush (which involves pressure and full fluid replacement) because of the risk of foreign matter being pushed into areas where it shouldn't be.

I have been recommended as getting one because the car I just bought had never had an auto service done in 200,000+ km. I got a standard service done straight away and asked the shop to see the pan and fluid before they dumped it and it was horrible, as you'd expect. And the magnets had thick coats of powdered metal on them too.

My plan was to do three auto servicings within a few hundred kms and hoped that doing this would get the fluid pretty clean - because just one service will not get the oil out of the converter.

Saying this plan to the next auto transmission place, (which happens to be an Ultra Tune here in Perth), the workshop manager said that was not a good way to do it and if I was worried about the old trans fluid staying in it, then I should opt for a full flush, but keep the pan on because it's already just had a new filter installed and pan cleaned out etc from the last service. He said doing this will use about 15 litres of ATF and isn't overly cheap at $550. Then again, 15 litres of Dex 4 synthetic would not be cheap.

I mentioned my worries about what I'd heard with pressure flushing but he said it would be all ok because it's just had the pan dropped and a new filter installed, so there shouldn't be any foreign stuff floating around.

BTW, he told me something I didn't know - a dry 6L80 transmission takes over 12 litres of ATF. A lot more than I expected. When you do a standard service, you are only changing about 5.7 litres - the rest stays all through the guts, valve body and converter. So maybe a flush is exactly what it needs.

Anyway, was just wondering if anyone here had had any bad experiences after this process, or heard of any? Thanks.

 

[figjam]

Not a Holden .......... our Territory had a power flush a few years ago at 112Km.
The ATF that they got out was clean, but the pressure blew off a line connection, which could be interpreted as good or bad, and made a mess that they had to clean up.
35Km later haven't noticed any difference in operation, but any crap in the system may have gone when I had the transmission cooler fitted when the warranty ran out.

 

[OldBomb]

just did the Mazda, but it has a drain plug. dare say most newer cars are the same.
measure the amount of fluid that comes out, then add the same quantity back into transmission via dipstick or fill hole. to do it properly & remove 90%-95% of the old fluid, you need to repeat this twice (total of 3 drains), driving about 60kms in between flushes. I very much doubt ultra tune would do this. Most likely they'll drain it once & refill whatever comes out.
As you know, a simple drain will only remove what's in the pan, which is less than half the ATF in the system. the rest stays in the torque converter & transmission itself. obviously this is why you need to repeat the drain & fill process multiple times. Plenty of videos on youtube.

Transmission fluid is a good cleaner. the theory is that new fluid will remove the sludge that's preventing the clutch plates from slipping

p.s ATF is on special at Repco at the moment. cost me abot $150 for 12 litres. of course the Mazda's transmission is only 8.1 litres

 

[Dart77]

Not a Holden .......... our Territory had a power flush a few years ago at 112Km.
The ATF that they got out was clean, but the pressure blew off a line connection, which could be interpreted as good or bad, and made a mess that they had to clean up.
35Km later haven't noticed any difference in operation, but any crap in the system may have gone when I had the transmission cooler fitted when the warranty ran out.

Thanks for the input FJ - I assume you mean 35k later... That's a lot of pressure then if it blew a line - it must have been a hose with a clamp on it. Hope they cleaned it up as it was before.

 

[Dart77]

just did the Mazda, but it has a drain plug. dare say most newer cars are the same.
measure the amount of fluid that comes out, then add the same quantity back into transmission via dipstick or fill hole. to do it properly & remove 90%-95% of the old fluid, you need to repeat this twice (total of 3 drains), driving about 60kms in between flushes. I very much doubt ultra tune would do this. Most likely they'll drain it once & refill whatever comes out.
As you know, a simple drain will only remove what's in the pan, which is less than half the ATF in the system. the rest stays in the torque converter & transmission itself. obviously this is why you need to repeat the drain & fill process multiple times. Plenty of videos on youtube.

Transmission fluid is a good cleaner. the theory is that new fluid will remove the sludge that's preventing the clutch plates from slipping

p.s ATF is on special at Repco at the moment. cost me abot $150 for 12 litres. of course the Mazda's transmission is only 8.1 litres

Ta for the input mate. And for letting me know re ATF on special. Got a Repco nearby too. Anyway, I can't do that myself as it's a bit in the too hard basket, also a bit in the too risky basket for one person without a hoist. of course, I could put it up on jacks, but I don't have a level driveway and need to have it running (on the stands) to get the correct trans temp on the dash for the refill procedure etc. The old VK with Traumatic was so easy.

In any case, what I understand, it's a pretty expensive piece of equipment that Ultra Tune has - it's a pressure/replacement/exchange system. So they would only need to do the cycle once, or "once" meaning, whatever cycle duration is required to replace the full amount.

They do a test drive before and afterwards - they have to really, to make sure it runs as good as it did before they flushed.

Be interested if other 6L80 owners have had the flush procedure.

 

[OldBomb]

no doubt ultra tune have an expensive machine to simultaneously capture old fluid & add new fluid, but as you say, is it detrimental to a high mileage transmission? The old VS did start slipping after a fluid exchange, but who knows if it was buggered to begin with. Before i got rid of it, changes from 1st to 2nd became very hard & 3rd back to 2nd would slip. 230,000km

 

[figjam]

Thanks for the input FJ - I assume you mean 35k later... That's a lot of pressure then if it blew a line - it must have been a hose with a clamp on it. Hope they cleaned it up as it was before.

35Km (35,000km), and it was a clamped hose line, which I will be getting them to check when the auto is scheduled for a proper service.

 

[J_D 2.0]

I was wondering if any V8 auto owners (6L80 trans) have found any dramas with their auto after having a transmission flush done? Have seen a few YT videos and heard of transmission places being reluctant to do the full flush (which involves pressure and full fluid replacement) because of the risk of foreign matter being pushed into areas where it shouldn't be.

I have been recommended as getting one because the car I just bought had never had an auto service done in 200,000+ km. I got a standard service done straight away and asked the shop to see the pan and fluid before they dumped it and it was horrible, as you'd expect. And the magnets had thick coats of powdered metal on them too.

My plan was to do three auto servicings within a few hundred kms and hoped that doing this would get the fluid pretty clean - because just one service will not get the oil out of the converter.

Saying this plan to the next auto transmission place, (which happens to be an Ultra Tune here in Perth), the workshop manager said that was not a good way to do it and if I was worried about the old trans fluid staying in it, then I should opt for a full flush, but keep the pan on because it's already just had a new filter installed and pan cleaned out etc from the last service. He said doing this will use about 15 litres of ATF and isn't overly cheap at $550. Then again, 15 litres of Dex 4 synthetic would not be cheap.

I mentioned my worries about what I'd heard with pressure flushing but he said it would be all ok because it's just had the pan dropped and a new filter installed, so there shouldn't be any foreign stuff floating around.

BTW, he told me something I didn't know - a dry 6L80 transmission takes over 12 litres of ATF. A lot more than I expected. When you do a standard service, you are only changing about 5.7 litres - the rest stays all through the guts, valve body and converter. So maybe a flush is exactly what it needs.

Anyway, was just wondering if anyone here had had any bad experiences after this process, or heard of any? Thanks.

Don’t do a full flush on the auto transmission. If it’s got high mileage on it then it can be relying on the grit in the fluid to provide sufficient friction for the engagement clutches.

If you flush all of the fluid then you will remove all of the grid which can result in the transmission slipping, forcing an immediate rebuild. Standard pan drop and filter/fluid change is entirely sufficient and a full flush is always unnecessary.

 

[07GTS]

it might be the clutch purge feature u can do to them that is the issue, as it purges the clutches any debris can be caught up in them which is why it has the warning not to do it on transmissions with alot of km

 

[vr304]

just did the Mazda, but it has a drain plug. dare say most newer cars are the same.
measure the amount of fluid that comes out, then add the same quantity back into transmission via dipstick or fill hole. to do it properly & remove 90%-95% of the old fluid, you need to repeat this twice (total of 3 drains), driving about 60kms in between flushes. I very much doubt ultra tune would do this. Most likely they'll drain it once & refill whatever comes out.
As you know, a simple drain will only remove what's in the pan, which is less than half the ATF in the system. the rest stays in the torque converter & transmission itself. obviously this is why you need to repeat the drain & fill process multiple times. Plenty of videos on youtube.

Transmission fluid is a good cleaner. the theory is that new fluid will remove the sludge that's preventing the clutch plates from slipping

p.s ATF is on special at Repco at the moment. cost me abot $150 for 12 litres. of course the Mazda's transmission is only 8.1 litres

Done exactly the same thing with my Mazda and worked out good using this method, done it myself and it really isn’t that hard