2.1 Waterboxer Auto box oil cooler problem - I think

[southpoint]

Hi Folks,
I have a 2.1 auto waterboxer Caravelle and I am getting problems with the gearbox oil cooler - I think it is leaking water into the ATF because I am suddenly getting ATF/water mix blowing through the torque converter seal which is only 3 months old so should be OK.

I have checked a spec drawing from VW of the oil cooler and it looks like the cooling occurs through 2 bolts that go through the centre of the cooler body - they have holes drilled in them and it is gasketed with 2 rubber O rings on each bolt seat?

What I dont want to do is to take it off & change the seals - if I can find them - and then cannot get it back on leak free - I can't see any markings on the bolts to tell me where to line them up - I am guessing that the holes have to line up accurately inside???? as they have AFT? Water? going through them - help

Can anyone give me some advice on what to do here and how to make sure that if I take it off it is re-fitted back OK and leak free?

Cheers all

[R0B]

i dont want to be the harbinger of doom.but have a read of this..http://www.gowesty.com/library_article.php?id=305

[Dubstar]

I don't think the bolts need lining up, they're just banjo bolts.There should be no crossover of water and ATF; from memory it's just a simple kind of heat exchanger. I'd change the exchanger as well as the seals. Mine is Aircooled and to fit the gearbox past the crossmember I had to remove the heat exchanger and put a connecting pipe between the 2 banjo unions - you could do this as a quick fix but if water is leaking into the gearbox if you bypass it and connect the water pipes together then ATF could leak out of the cooler.

[Ian Hulley]

I'm not going to speculate on the why's and wherefores cos I don't know auto's BUT if you've had ATF through the cooling system be warned ... ALL the hoses are in danger of turning to mush and bursting. I'm not joking .. you need to THOROUGHLY flush the cooling system once you've discovered where the leak is and have cured it.

The oil cooler, heater radiator and main radiator are particularly popular places for the gunge to gather .... bear that in mind.

Ian

[R0B]

have you read my gowesty link above.they do fail internally.and judging from this

because I am suddenly getting ATF/water mix

that would appear to be the case.

There should be no crossover of water and ATF

[R0B]

The problem was that when the cooler did fail, it failed internally. When this happened, it allowed the two fluids (ATF and coolant) to mix. So, the transmission would be filled with coolant, and the cooling system got contaminated with ATF. The result is a ruined transmission ($2500) and a ruined cooling system ($3500). We have seen some really long faces in our shop caused by this little bugger.

[southpoint]

Thanks for the repies guys!

Going to take a look under today and strip it down properly to see what's going on - that gowesty lnik looks scary tho

Cheers

[Dubstar]

Just in case things are bad, the actual gearbox - not the diff bit - is the same gearbox as Audi 80's from the 1990's, about 90 to 96; if you do split the box from the diff there are 2 rubber seals, on either end of the input shaft to keep the ATF and gear fluid separate. But when you do have a look, don't forget to drop the gearbox oil and fit a new sump gasket.

[southpoint]

Hi Guys,
The Plot thickens here !!!
I have just crawled out from having a good look under the van, getting it cleaned up and just running the engine [standing] for 5 minutes or so.
I had a look at the oil cooler and it seems OK - when I took out the banjo bolts there was no water around it was just really dirty ATF? this is what fooled me, when I saw the stuff on the outside, into thinking it was contaminated with water.

The ATF that is coming out very dark and dirty and looks almost like it's mixed with normal oil and it is definately thinner - running the engine this was pouring out of the torque converter bell housing spraying everywhere.
We fitted a new Torque converter seal and new ATF a couple of months ago.

I am again a bit lost here - how can the ATF get contaminated like this - especially with oil - final drive seal or something somewhere ?????

And could the new seal have failed - it had been running nice and dry since the new seal went in!!

Thanks guys

[Dubstar]

Are you sure it is ATF fluid? The only oil that can mix with ATF is the final drive oil so that would surely thicken it. It could be engine oil leaking out of the rear seal and into the bell housing making it look like it's coming from the gearbox. Take the gearbox dipstick out and see if the oil is as black and dirty as the stuff coming out of the bellhousing. I'm going to guess it'll be nice and pink like it should be and that it is the rear crank seal that's leaking.

[R0B]

if you haven't already.it would be worthwhile checking the atf strainer as well.brickwerks sell these.should you need to replace it.http://www.brickwerks.co.uk/index.php?p ... t&Itemid=6

[southpoint]

Definitely a mix of ATF fluid - you can see a pink tinge to it when you catch it on a clean board under the van.

Will check what's on the atf dipstick in a mo just to check it and post back

Thanks again

[southpoint]

No no no no - I am totally wrong here - I think!!!

Just pulled out the ATF dipstick and it is bright shiny pink ATF - lovely and clean - you were spot on.

The oil that was running out tho definitaly had a slight pink tinge to it so now I am confused? The rear crank seal makes total sense as the stuff running out is as brown as engine oil.

I reckon If I have to drop the box again to sort the crank seal I will replace the torque converter seal again and get both bits new at the same time.

Thanks a lot for pointing me in the right direction

[Dubstar]

It could have a slight leak past the input shaft seal, mixing it with the engine oil as it's coming out. Also, just check the gearbox sump isn't leaking ATF or where the dipstick tube goes into the sump. When it leaks as soon as it gets to the torque convertor then it gets flung round and mixed with all the oil there, hence it makes you think it's leaking past the input shaft seal. Even new sump gaskets can leak;I had to put sealer round mine because it just wouldn't stop, although it was only a slight leak. Check the level in the box as well as it may be only a slight leak or it could be loads.

[Dubstar]

I'm insanely paranoid about my autobox going so I'm always looking for leaks and listening for noises. About 18 months ago I had a bit of a leak I didn't notice but when I first started it up you could hear a whining noise from the gearbox area that sounded a bit like an electric fuel pump. Only lasted a few seconds but it was because the ATF was so low that the noise was the pump in the gearbox trying to suck in the ATF. It also rolled backwards a yard or so on hillstarts, again because of the lack of ATF. I fixed the leak and all has been ok since, but if you get any of the above symptoms then it means your ATF is really low; mine was off the dipstick and took nearly 2 litres to bring up to the full mark!