4hp20 second gear

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teo
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Re: 4hp20 second gear

Post by teo » 26 Jul 2017, 08:22

Ok I haven't expected this issue is not really clear and so deep analysis arise. Anyway nobody here is sure it's better to stop using the car now so I continue to enjoy smooth and comfort ride as it is. I will let you know here if there is any change. Thanks for you sharing your knowledge and opinions. Regards Tomáš

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xantia_v6
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Re: 4hp20 second gear

Post by xantia_v6 » 26 Jul 2017, 10:01

The damage is probably already done, but it would probably last longer before total destruction if you have the correct fluid installed.

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teo
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Re: 4hp20 second gear

Post by teo » 04 Apr 2018, 13:47

story continues and ... happy way... car has done 11 000 km more since BG PF5 cleanup and filling with petro canada RED "wrong" oil and behaviour is still same .... no noticable change in comfort or sound. I must mention this car runs really in severe conditions. Used mostly for short trips (no money for electric car yet) and this winter it got lot's of starts in -10°C and below for 3km trip only so I know this is really not good even it's petrol engine. Anyway winter is over so let's go further into warmer.... Regards

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Re: 4hp20 second gear

Post by EDC5 » 04 Apr 2018, 21:18

teo wrote:
04 Apr 2018, 13:47
story continues and ... happy way... car has done 11 000 km more since BG PF5 cleanup and filling with petro canada RED "wrong" oil and behaviour is still same .... no noticable change in comfort or sound. I must mention this car runs really in severe conditions. Used mostly for short trips (no money for electric car yet) and this winter it got lot's of starts in -10°C and below for 3km trip only so I know this is really not good even it's petrol engine. Anyway winter is over so let's go further into warmer.... Regards


Interesting, I've just re-read this thread. I've got the AM6 gearbox (Aisin TF80) and this, too, requires a very specific grade of oil. I must have found hundreds of threads on the internet with heated debates around what oils can be used and what oils will cause immediate destruction of the gearbox! :oops:

Personally I've never wanted to chance it and have always found OEM oil made my Mobil for the gearbox but I've read about plenty of others using different oils without dire consequences.

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Re: 4hp20 second gear

Post by Zelandeth » 04 Apr 2018, 22:04

EDC5 wrote:
04 Apr 2018, 21:18
teo wrote:
04 Apr 2018, 13:47
story continues and ... happy way... car has done 11 000 km more since BG PF5 cleanup and filling with petro canada RED "wrong" oil and behaviour is still same .... no noticable change in comfort or sound. I must mention this car runs really in severe conditions. Used mostly for short trips (no money for electric car yet) and this winter it got lot's of starts in -10°C and below for 3km trip only so I know this is really not good even it's petrol engine. Anyway winter is over so let's go further into warmer.... Regards


Interesting, I've just re-read this thread. I've got the AM6 gearbox (Aisin TF80) and this, too, requires a very specific grade of oil. I must have found hundreds of threads on the internet with heated debates around what oils can be used and what oils will cause immediate destruction of the gearbox! :oops:

Personally I've never wanted to chance it and have always found OEM oil made my Mobil for the gearbox but I've read about plenty of others using different oils without dire consequences.


Therein lies the problem in many cases...

It's somewhat of a lottery as to how compatible supposedly compatible oils are. The effects they might have on a nearly new gearbox may be massively different in a nearly new one to one that's got 20+ years and 100k or more miles on. It's one thing to say "it's fine to use this from day one" but quite another to say it won't react differently to the wear and contamination that will be found in an older box.

Personally, I'd just never take the chance...£100 or less of fluid is far cheaper than having to change the gearbox if things don't co-operate nicely.

One thing I've seen happen on a commercial box that had failed was that it had effectively cleaned a lot of surfaces - which had then gone and clogged up the main valve block. Probably would have been absolutely fine in a new gearbox, but behaved differently when added to an older one.

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EDC5
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Re: 4hp20 second gear

Post by EDC5 » 04 Apr 2018, 22:38

Zelandeth wrote:
04 Apr 2018, 22:04

Therein lies the problem in many cases...

It's somewhat of a lottery as to how compatible supposedly compatible oils are.

Personally, I'd just never take the chance...£100 or less of fluid is far cheaper than having to change the gearbox if things don't co-operate nicely.


Interesting. I, like you, would not take the chance by not using the specified grade and manufacturer of oil, even if it costs more. In the case of the AM6, the only official oil to use is Mobil 3309 oil, I have always bought this oil but am I wrong to disregard oils by other reputable manufacturers that claim to meet this spec? For example, this (https://www.ebay.co.uk/itm/ATF-JWS-3309 ... Xg4ClHDyXQ). Surely no reputable oil company would claim to make an oil that meets one specific standard then... not meet it.

Zelandeth wrote:
04 Apr 2018, 22:04

One thing I've seen happen on a commercial box that had failed was that it had effectively cleaned a lot of surfaces - which had then gone and clogged up the main valve block. Probably would have been absolutely fine in a new gearbox but behaved differently when added to an older one.
That's something worth considering, probably a good idea that you can only change a few litres at a time then that way each successive drain brings the freshly liberated crud with it.

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Zelandeth
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Re: 4hp20 second gear

Post by Zelandeth » 04 Apr 2018, 22:48

Not sure that would have done much in this case. The sump was dropped and the filter changed when it was done (on a pump apparently, so a "full flow change"), and the filter was spotless. Everything that had dislodged itself and clogged the valve block up was from upstream of the filter. I think the box was doomed from the moment the fluid was changed. Not sure exactly which gearbox model it was, but it was an Allison box out of a Dennis Dart. It had had plenty of changes during its life, and had never had any issues. This had happened immediately following the operator switching supply contracts from one supplier to another so the brand used apparently changed.

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EDC5
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Re: 4hp20 second gear

Post by EDC5 » 04 Apr 2018, 23:04

Zelandeth wrote:
04 Apr 2018, 22:48
Not sure that would have done much in this case. The sump was dropped and the filter changed when it was done (on a pump apparently, so a "full flow change"), and the filter was spotless. Everything that had dislodged itself and clogged the valve block up was from upstream of the filter. I think the box was doomed from the moment the fluid was changed. Not sure exactly which gearbox model it was, but it was an Allison box out of a Dennis Dart. It had had plenty of changes during its life, and had never had any issues. This had happened immediately following the operator switching supply contracts from one supplier to another so the brand used apparently changed.


Sounds like a different detergent package loosened all of the crud in one go!

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Zelandeth
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Re: 4hp20 second gear

Post by Zelandeth » 05 Apr 2018, 02:58

Yep. That's exactly what we figured. The box by the way was revived with another valve block from another box that had suffered a catastrophic mechanical failure. There weren't any signs of adverse wear or anything. It's still going now as far as I know.

That's the sort of compatibility issues which I worry about with supposedly compatible oils though. I don't reckon either of the oils used would have been an issue (especially being an older commercial box I doubt it will have used anything essoteric) in isolation... it's the fact that the specific detergents behaved differently in this specific situation to each other that caused the issue. Sadly I don't know the products that were actually used before and after, as it would be interesting to know.

It's down to everyone what they do with their own car though. I'm sure that 95% of cases where compatible oils are used are fine. The issue is that there are a truly massive number of garages who don't seem to realise that not all "old cars" don't just use Dex II/III fluid. Had that issue trying to convince a garage that the Saab didn't want that...took an age to get them to agree that the old Ford type F fluid was needed.

The plethora of proprietary fluids out there these days just makes it so much more of a minefield... especially when things are changed and superceded, so you need to follow the paper trail to make sure you're getting the right thing - not just what some motor factor's website stock checker tells you is right. Those blasted things are often wrong - especially for specialised things like this.

It's not that older boxes were more forgiving I think (though to some extent they probably were), but that there were maybe five or so main types of fluid used in the 80s, while there are now literally dozens...even varying between types on exactly the same model of car at different production dates on the same year. That combined with garages being as guilty as anyone of believing the first source of data they find makes it more common a problem to see nowadays.

...Plus the fact that duff into on the web seems more common than it used to be in proper service books. Except for Intermotor ignition parts...their catalogue was always terrible!

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Re: 4hp20 second gear

Post by ekjdm14 » 05 Apr 2018, 16:03

Zelandeth wrote:
04 Apr 2018, 22:48
....it was an Allison box.... there's the first problem



out of a Dennis Dart.... and here's the main one



lol as a passenger I never liked the things, bouncy clattery rattleboxes either too hot or freezing. ZF box would have been nicer, might stand a chance of hearing it over the bodywork then too!

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Re: 4hp20 second gear

Post by 406GTX » 29 May 2018, 08:47

In 2016 the 4HP20 in my 406 V6 started to give a slightly rough 2 > 3 gear change but only when the engine was cold. I had an oil change done by an autobox specialist in Reading who put Dexron 6 into it. Immediately all the changes were much smoother and the 2 > 3 change improved although it still flutters a bit on light throttle when cold. It’s has the feeling of a double de-clutch on a manual gearbox. The car has now done 160k miles and, 2-years on, the autobox is better than it was before the oil change.