1989 Auto trans fluid rising?

[JealousJack]

Hey all,

My auto trans 89 Vanagon transmission started leaking recently from around the pan. I went to check the level of fluid- and it seems to be above the top dot cold, indicating that the fluid level is rising.

Is that indicative that the internal cooler is failing and pouring coolant into the transmission? Has anyone dealt with this before and how did you address it?

Thanks!

[MarkWard]

Coolant mixing with ATF would give you a milkshake looking mixture. I’d check the level in the differential first. Then set the level of the ATF to spec. Then see if it’s gaining.

There are 2 seals back to back that keep the ATF and Gear oil separate. They do fail.

[67rustavenger]

[JealousJack]

Yeah I know that smell, and I definitely don’t smell that. The coolant itself looks pretty good- clear and not like milkshake- and the ATF on the dipstick is red and oily as notmal. I haven’t drained the ATF to see what that looks like though.

Was planning on driving a good 6 hours in it today- looks like we’re taking the car!

J

[67rustavenger]

[JealousJack]

I’m not sure if this makes any different whatsoever but I replaced my water pump very recently- I’m not sure how that could impact a transmission, but prior to that, I had no leaks.

I suppose I could see a world in which the coolant system wasn’t bled properly, causing the oil cooler to break and leak into the transmission, compromising seals that may have been on their last legs?

I’m also new to the auto. I knew my way around my 86 manual pretty well- but the autos seem to have less documentation on the internet.

[clamay]

The only accurate way to check the level of the ATF is with the transmission fluid hot and at idle in park.
_________________
91 Carat, automatic, GW 2.2, GW EFI, Peloquin TBD

When you come to a fork in the road, take it. --Yogi Berra

[67rustavenger]

[kamzcab86]

[JealousJack]

Thanks guys, good to know! I guess I read somewhere that checking cold was the way. Glad to hear it.

Ok, so things so far aren’t looking as bad as I figured. Not sure I want to risk a trip today (we were about to drive 6 hours), but perhaps I start with gaskets, inspection, filter etc. when we get back.

The transmission seems to be functioning amazingly. Barely noticeable shifts!

[Wildthings]

If you fill to the mark cold, as it gets hot the fluid with expand the blow out wherever it can.

[SCM]

[JealousJack]

[kamzcab86]

[jlrftype7]

here's Kourts fill/check sheet that I copied as a reference out of his thread. Straight from the Bentley.

_________________
'68 Westy- my first VW and vehicle/Bus- long gone.- sold it to a traveling Swiss couple....
'67 Type 3 Fastback, my 2nd car- gone
'69 Semi-Auto Stick Shift Beetle-gone
2017 MINI Coopers, our current DDs
‘84 Tin Top - Hilga....Auto

[jlrftype7]

As for Coolers, we're still running the GoWesty cooler set-up from a few years ago install. It didn't work for Kourt in his set-up, so he ran an aux fan assisted version to get better cooling and ditched the Gowesty version.
But, we're up in Chicago, so we don't see the temps Kourt was running into down in Texas day to day.
_________________
'68 Westy- my first VW and vehicle/Bus- long gone.- sold it to a traveling Swiss couple....
'67 Type 3 Fastback, my 2nd car- gone
'69 Semi-Auto Stick Shift Beetle-gone
2017 MINI Coopers, our current DDs
‘84 Tin Top - Hilga....Auto

[SCM]

[Shonandb]

Regarding the trans fluid cooler, I went with a 2' aluminum finned cooler with a 180F thermo unit as I didn't want to have any issues using a fan dependent oil cooler. I have 40,000 km on my swap and regularly pull a sport trailer and drive in the mountains during the summer (90F - 100F) and haven't had any issues. I recently did a trans fluid change and the filter and pan were clean so the cooler has been effective but I didn't know the actual operating temps.

To get a better sense of actual temps, I installed a sensor and gauge for trans fluid temp and the output temp gets up to about 120C while pulling a long hill at 120 kph before the cooler and is around 100C after the cooler flowing back into the transmission. Normal driving is around 95C coming out of the trans and 75-80C after the cooler. flowing back into the trans. The normal stock cooler basically runs at the same temp as your engine coolant so I think my trans fluid is running a bit cooler than normal.

A pic from 2018 when I was installing.

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76 Westy with a 2.5L Subaru SOHC + Vanagon (010) Automatic Transaxle
Build & Trip Thread: https://www.thesamba.com/vw/forum/viewtopic.php?t=758760
Previous 1973 Panel Bus:
Click to view image

[JealousJack]

Ok, so what I’ve learned from those helpful links is mainly-
My oil is not fluctuating. What’s been happening is I’ve been checking the van OFF. It doesn’t explicitly say in the Bentley but the 20 degree mark, but it has to be running when you do that initial check. Then you warm it up and check again (driving 10 miles or so).

So everything is fine on that end. I still can’t quite figure out what fluid I’m leaking. I left for the weekend and put a piece of white thick paper under the van. When I came back, it was hard to tell which color and the smell isn’t really anything. I don’t smell ATF, or coolant. It’s definitely oil, or oily. I’ll drop an actual clear pan under it the next couple days. Fairly convinced it’s atf from the time I put my finger right up to it.

One thing I was inspired by in the literature provided was one member who didn’t want to cancel his trip but also didn’t have time to reseal the trans. He ended up driving 10,000 miles in the end and all was fine till he got to the repair. So I’m going to continue to monitor it and enjoy the rest of the summer. I’ll pull the transmission in the winter, install a few seals and the large o-ring and do the cooler at the same time.

Appreciate all the help guys.

Jeff

[Abscate]