Best ATF

[Bonneville]

Previous posts recommended Millers DM for our boxes as a Dexron 3 equivalent but also mentioned Millers SP3. It's been a while since then (2011!) so what do folk recommend now assuming cost not an issue? Is anyone using Dexron 6 or other brands like Fuchs ATF4400?

[mikeonb4c]

When i did a scheduled ATF change a few years back I tracked down and bought Millers. But with a recent incident where a corroded pipe ruptured and i had to sort it on the drive in a hurry, i settled for whatever Halfords had in stock (Comma i think) as i could cycle to them. Such is life!

[TheLongRoad]

Mikeonb4c did you notice any difference after the ATF change? Was it quieter or smoother changing gear? Some folks advocate leaving it alone in case muck in the internals is dislodged and causes more issues. Being the first Auto I’ve owned this area is new to me.

[Flanners]

Looking at the babble on the internet...change the ATF anywhere between 30-60k miles then carry on changing at those intervals, if it has never been changed and the transmission has done 100K+ miles then some just leave it alone. Not very scientific, sealed for life systems are purported to be a fallacy? Guess it boils down to personal choice, most seem to change the fluid when they already have problems/wear/damage and the new fluid can exacerbate this...or so some of the articles suggest. I am looking at changing mine out at 50K miles so in a year or so, I have no issues having sorted the TPS position (this was causing odd shifting) box is silent and super smooth. Previous owner stated that the ATF had been changed (in 2015) year after import and the fluid is cherry red and no smells but I don't have any documentation of that change. The prevalence of autobox's in the UK has historically never been that big so maybe the lack of ATF maintenance/changes over the year's has been more down to ignorance.

[TheLongRoad]

Mine has also covered less than 50k miles and the ATF is a nice colour and doesn't smell. Plenty of time to consider my future approach.

[mikeonb4c]

I think Flanners has it covered. Not done many miles on my new ATF but can't say i noticed any difference after any of my ATF changes, though old fluid always looked good anyway.

[g8dhe]

In the transmission you haven't got all the combustion products getting past the pistons mucking the oil up, so provided its not allowed to overheat the oil should stay in pretty good condition unless the gears start eating themselves

[Tony x]

We used to use ATF in 50cc motocross bikes. Oil changes were every hour (every 20 minutes when wet) the little auto clutch taking 1/2 litre a time. The oil would get a right hammering and would always come out black and smelling burnt.
Motorex was the most popular choice and appeared to last and perform as good as anything and better than most.

[Alacrity]

From the horses mouth http://www.autogearboxes.co.uk/docs/lifegard.pdf.

'Filled/Sealed for life' is a CAR manufacturer selling point as it reduces service costs. ZF, as linked to above, make transmissions for many of todays cars &, as can be seen, advocate oil changes. BMW & Jaguar - who use ZF gearboxes - say they are 'Filled/Sealed for life'. Ask yourself the question "what is the gearbox life?" Lets say (hypothetically) 100k without servicing or 150k with servicing. Simple really. ALL gearboxes can have the oil changed no matter what anyone tells you, quite a lot cannot have the filter changed, but oil changes are doable on all. The above info will vary with CVT units (bad news anyway unless it is a Toyota) & DSG/DCT units.

ALWAYS use the correct oil especially in ZF, CVT & DSG units (I know this doesn't apply to Bongo's but it good general info) & be wary of 'equivalents'. There are none for ZF despite the eBay claims & if it is cheap, ask yourself why.

I my experience changing the oil on a good transmission will not make any difference to the way it drives, it will just prolong its life (as long as it is done correctly!). Others on here claim miracles after an oil change but I have yet to experience it & I thought I would have done in 39 years of doing autos!

[mikeonb4c]

Great advice as ever Geoff