Auto Gearbox Servicing - Any Thoughts?
Discussion
Any experience or opinions on getting Auto gearboxes serviced? Understand most are supposed to be sealed for life but that makes no mechanical sense to me. Second hand car so not sure if it's ever been done, it's a Kia so not on any maintenance schedule. Can't hurt to get the fluid changed in my opinion. All experience appreciated!
DSG gearboxes used to be sealed for life and now there are service intervals for the oil and new filters. Most dealers can replace the fluid. In days of yore, you could only drain out a certain % of the fluid manually but many places now use suction/vacuum pumps.
If you struggle to find someone to do it, then look up an automatic transmission specialist on fedauto.co.uk
If you struggle to find someone to do it, then look up an automatic transmission specialist on fedauto.co.uk
So, when they say "filled for life" what they actually mean is filled for the expected life of the vehicle.
Every manufacturer will design their vehicles to an expected life, I've heard different values (it will depend on manufacturer) but you can probably take somewhere around 10 years or 120k to be a reasonable guestimate at "design life". That doesn't for a second mean they will fall apart and break as soon as they hit 120k but you can expect more failures to occur once they've passed that figure. The gearbox may be fine for example to 140k, 20k past its design life and assuming UK average of 7k a year 20 years old! All well and good unless you want it to last longer than that.
The issue is however that you really don't want to run it to 120k and *then* change the fluid, ideally you'll want to change it much earlier.
With automatics the fluid will inevitably accumulate debris over time as the gearbox wears, in a manual gearbox that debris isn't typically an issue, most will settle out as they're splash fed. In the auto there is a pump and the fluid is also used for the sensitive valves (plus a load of sensors). Debris in the fluid will wear things to the point that eventually things will fail. By changing the fluid you get rid of that debris and so reduce both the wear and potential contamination of sensors that would eventually cause the gearbox to fail or misbehave.
IIRC in BMW autos there is a tendency for them to fail at about 140k which is why its generally a good idea to change the fluid at about 80k or so if you intend on keeping it long term.
If I had an auto I wanted to keep long term I would 100% change the fluid every 60-80k or so.
Every manufacturer will design their vehicles to an expected life, I've heard different values (it will depend on manufacturer) but you can probably take somewhere around 10 years or 120k to be a reasonable guestimate at "design life". That doesn't for a second mean they will fall apart and break as soon as they hit 120k but you can expect more failures to occur once they've passed that figure. The gearbox may be fine for example to 140k, 20k past its design life and assuming UK average of 7k a year 20 years old! All well and good unless you want it to last longer than that.
The issue is however that you really don't want to run it to 120k and *then* change the fluid, ideally you'll want to change it much earlier.
With automatics the fluid will inevitably accumulate debris over time as the gearbox wears, in a manual gearbox that debris isn't typically an issue, most will settle out as they're splash fed. In the auto there is a pump and the fluid is also used for the sensitive valves (plus a load of sensors). Debris in the fluid will wear things to the point that eventually things will fail. By changing the fluid you get rid of that debris and so reduce both the wear and potential contamination of sensors that would eventually cause the gearbox to fail or misbehave.
IIRC in BMW autos there is a tendency for them to fail at about 140k which is why its generally a good idea to change the fluid at about 80k or so if you intend on keeping it long term.
If I had an auto I wanted to keep long term I would 100% change the fluid every 60-80k or so.
I've recently bought a 2016 Honda crv on 68k miles, no evidence of fluid being changed, actually put it into a dealer, as it was cheaper than an independent.
Definitely changes more smoothly now, unfortunately they will only use Honda specified fluid so it was over £300, peace of mind for me.
Definitely changes more smoothly now, unfortunately they will only use Honda specified fluid so it was over £300, peace of mind for me.
Generally speaking, if the fluid's knackered then the transmission's knackered. But having said that, a precautionary fluid and filter change (no point doing just the fluid) at 10 years/100,000 miles can't be wrong, and it's lot cheaper than a transmission rebuild. One advantage of dropping the pan is you can see what's in there - probably crud from clutches but obviously bits of metal would sound alarm bells. There's generally a magnet in there somewhere.
If you're fretting about transmission fluid then think about your differential as well.
All of this assumes there's no scheduled servicing specified by the manufacturer. Some DSGs/DCTs will have a 5 years/50,000 mile change specified in the schedule.
If you're fretting about transmission fluid then think about your differential as well.
All of this assumes there's no scheduled servicing specified by the manufacturer. Some DSGs/DCTs will have a 5 years/50,000 mile change specified in the schedule.
Land Rover would say the ZF boxes were firstly sealed for life.
Then it was 10 years or 150,000 miles.
Which was at odds with ZF saying 75-90,000 miles.
My Discovery 4 got its 8 speed ZF serviced at 90,000 miles, I’ll be getting it done again at 130,000 miles and keep to 40,000 mile intervals.
Oil is cheaper than metal so personally, I would be asking a gearbox specialist if they can change the oil for you.
Then it was 10 years or 150,000 miles.
Which was at odds with ZF saying 75-90,000 miles.
My Discovery 4 got its 8 speed ZF serviced at 90,000 miles, I’ll be getting it done again at 130,000 miles and keep to 40,000 mile intervals.
Oil is cheaper than metal so personally, I would be asking a gearbox specialist if they can change the oil for you.
Make no mistake, sealed for life does not mean that. It means that it won’t need a fluid change, whilst the original manufacturer is liable for the repair.
DSG boxes aren’t really autos as such. They’re s robotically controlled manual gearbox with a clutch. Well,two gearboxes and two clutches really….
DSG boxes aren’t really autos as such. They’re s robotically controlled manual gearbox with a clutch. Well,two gearboxes and two clutches really….
I’ve observed a few things:
Fluid changes may prevent failure.
Fluid changes cannot fix a broken gearbox.
Good ATF is surprisingly expensive. Not as expensive as a new gearbox.
It’s usually recommended that you have adaptations reset after a change. But not always. Common sense suggests you should.
Fluid changes may prevent failure.
Fluid changes cannot fix a broken gearbox.
Good ATF is surprisingly expensive. Not as expensive as a new gearbox.
It’s usually recommended that you have adaptations reset after a change. But not always. Common sense suggests you should.
For the ZF6 auto in my 3-Series, BMW claim it's "sealed for life". However, ZF themselves say otherwise and advise it should be done around every 60-80k miles. I had the gearbox serviced at around 120k, because it hadn't been done. It wasn't displaying any issues, but worth it for peace of mind and longevity.
Have always renewed gearbox oils at sensible intervals whatever transmission type is fitted, am yet to have a gearbox failure and you do notice improvements in gearbox operation every time.
Interesting thing about the autobox on my Forester, it has a spin on filter which looks just like an engine oil filter but designed to filter only a fraction of the oil continually where all the oil passes through an engine filter as it circulates the engine.
Having a disptick tube for refilling makes the Forester autobox change slightly easier than changing the engine oil, filter change isn't every time.
Intererstingly Subarus also have a third dipstick under the bonnet, for the front diff.
Toyota surprised me with Landcruiser/Prado and not in a good way, from around 2004 the 4 speed autobox became a 5 speed, there's no specific service interval apart from level checking, instead every so often an oil sample is supposed to be taken and tested, its a faff and you might as well just get on and change the fluid.
In practice most reasonable owners either change the oil themselves (not as easy on the 5 speed which lacks a dipstick and the filler point isn't easy to access) or get it done at an indy.
Interesting thing about the autobox on my Forester, it has a spin on filter which looks just like an engine oil filter but designed to filter only a fraction of the oil continually where all the oil passes through an engine filter as it circulates the engine.
Having a disptick tube for refilling makes the Forester autobox change slightly easier than changing the engine oil, filter change isn't every time.
Intererstingly Subarus also have a third dipstick under the bonnet, for the front diff.
Toyota surprised me with Landcruiser/Prado and not in a good way, from around 2004 the 4 speed autobox became a 5 speed, there's no specific service interval apart from level checking, instead every so often an oil sample is supposed to be taken and tested, its a faff and you might as well just get on and change the fluid.
In practice most reasonable owners either change the oil themselves (not as easy on the 5 speed which lacks a dipstick and the filler point isn't easy to access) or get it done at an indy.
Yes, ‘sealed for life’ is total b0llocks.
Reality is every 60k or 10 years, whichever occurs first.
But should you flush & fill or simply drain & fill? Depends on the oil’s colour / condition, watch this:
https://m.youtube.com/watch?v=o690DovjDAc&t=23...
However, the Car Care Nut, an ex-Lexus / Toyota master tech, advises that if an autobox is over 100k and/or 10 years old and has never been serviced, leave it be. Hmm…
Reality is every 60k or 10 years, whichever occurs first.
But should you flush & fill or simply drain & fill? Depends on the oil’s colour / condition, watch this:
https://m.youtube.com/watch?v=o690DovjDAc&t=23...
However, the Car Care Nut, an ex-Lexus / Toyota master tech, advises that if an autobox is over 100k and/or 10 years old and has never been serviced, leave it be. Hmm…
Edited by NGK210 on Friday 29th November 20:24
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