auto "diff" full of auto fluid!

[Mark Shutt]

today I thought I would do a bit of routine maintenance in preparation for a long trip next month, when I undid the 17mm grub screw on side of diff I was greeted by about a litre of auto transmission fluid! it was way above hole and by the time I thumbled about trying to get screw back in it was everywhere this doesn't look good at all and I want to know how it got in there, I'm guessing a shot seal but the auto side still has clean fluid and full although when I changed that last year it was greyish

is it possible when I had the whole assembly out when the car was rebuilt that it could have seeped in when upside down when I painted the box/diff? I'm just amazed how much fluid was in there, or is it possible if the auto side was overfilled it could had gone in the diff?
_________________
1968 1600TL Auto build thread, have a look!

http://www.thesamba.com/vw/forum/viewtopic.php?p=6007222#6007222

[one4house]

2 things;

1) There is a seal between the governor and the diff that would allow the fluid to intermingle. The automatic transmission fluid lubricates the governor.

2) I have no personal experience with this, but the auto fluid in the diff is a no-no. The rumor is that it will allow the ring and pinion to tear itself apart rather quickly. I have seen a picture of one that was allowed to have both fluids together and it is not pretty. I will see if I can find the picture. It was missing about 1/4" of the teeth on the ring and was about to explode. 1/2" of backlash will do that.

From my experience, replacing that governor seal requires taking the auto unit apart from the differential. I am trying to remember if changing that seal would be possible without the tear down, but my memory is telling me no. I do not think that you could get the new seal back in from the outside. I think it is going to have to be installed from inside the differential.

If you have auto fluid in the diff, DO NOT run the car. It might be time to tear it down and make sure the differential is OK.
_________________
My Old 64 Field Find
My Old 66 Squareback
My Old 66 Beetle
My Old 70 Squareback

[KTPhil]

Probably need to replace the seal. If it has been a while, more damage may have occurred. Check out:

http://www.thesamba.com/vw/forum/viewtopic.php?t=516066

http://www.thesamba.com/vw/forum/viewtopic.php?t=489935

[one4house]

Here is a picture of a user named Just Shep's differential after he had ATF get in. He bought an extra differential I had for his auto. I have no idea how long they were mixed before he noticed. You might try and send him a PM.

_________________
My Old 64 Field Find
My Old 66 Squareback
My Old 66 Beetle
My Old 70 Squareback

[one4house]

Also Multi69s might have an answer as to if the governor seal can be changed without taking the transmission apart.
_________________
My Old 64 Field Find
My Old 66 Squareback
My Old 66 Beetle
My Old 70 Squareback

[Mark Shutt]

not looking good then now the diff is drained I might run the engine for a bit then see if any auto fluid seeps through to the diff overnight, if not I might just fill the diff up and keep an eye on it for a while..
_________________
1968 1600TL Auto build thread, have a look!

http://www.thesamba.com/vw/forum/viewtopic.php?p=6007222#6007222

[Donnie strickland]

Don't run the car. That seal is shot. There's a good explanation of how to get to it here:

http://www.thesamba.com/vw/forum/viewtopic.php?t=516066&highlight=
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71 Elm Green FI A/T Squareback

[Mark Shutt]

thanks for the replies guys, apparently my box was overhauled at some point and I'm guessing they didn't touch the diff, if the governor seal can be changed without pulling the transmission out then I'm willing to give this a shot 1st. the box itself seems fine and runs great.
_________________
1968 1600TL Auto build thread, have a look!

http://www.thesamba.com/vw/forum/viewtopic.php?p=6007222#6007222

[Multi69s]

Mark,

You really need to pull the trans and replace the main seal and the governor seal. Otherwise you WILL end up destroying the diff. I don't know how common autos are in the UK, but they are getting kind of scarce here in the states. The trans fluid did not get into the diff from being moved around, it got there because the trans fluid is under pressure and it went past the seals. Unfortunately, to change the seals you will have to drop the trans and separate the trans from the diff. The hypoid action of the ring & pinion creates a huge amount of friction / pressure on the gear set. When you dilute the gear oil with trans fluid, it WILL destroy the R&P in a very short amount of time. So if you plan on keeping the car, you have to bite the bullet and change out the seals. There is no shortcuts here.
_________________
69 road Bug 2110
73 Squareback - 2L, T4, Automatic W/ AC
Gone, but many fond memories 69 Baja Bug 2010 - 5 Rib Bus Transaxle
Gone but not forgotten 72 Baja Bug 2010
My builds
T4 into Squareback http://www.thesamba.com/vw/forum/viewtopic.php?t=458944&highlight=
Auto Trans Rebuild http://www.thesamba.com/vw/forum/viewtopic.php?t=516066&highlight=
AC in Squareback https://www.thesamba.com/vw/forum/viewtopic.php?t=...highlight=

[Mark Shutt]

this is where I'm up to! need to source the gaskets but have found the seals locally, if I have to I will make the gaskets. I'll strip the diff down tomorrow and see if there's any damage..

this is the little bugger in question, it was held in with only 3 studs as one was sheared off and a bolt held in the end with silicone!

_________________
1968 1600TL Auto build thread, have a look!

http://www.thesamba.com/vw/forum/viewtopic.php?p=6007222#6007222

[Mark Shutt]

took the diff apart today and all looks quite good, the crown and pinion have no visible wear but there is a slight bit of play before they engage, not sure if this is correct or if it can be adjusted out? I have the brown Bentley manual but not sure where to start or if it's a bad idea to be DIY-ing the play out without correct tools..

I could also do with the 2 gaskets that the flanged shafts are sealed to the case to, I have no idea where to get these from! also need the 2 other gaskets for TC end an also diff to box seal. if push comes to shove I could make the latter and just reseal the others with gasket sealer but I would rather do the job right

Mark.
_________________
1968 1600TL Auto build thread, have a look!

http://www.thesamba.com/vw/forum/viewtopic.php?p=6007222#6007222

[Mike Fisher]

Jim Adney told us yesterday that he has gasket set you need & shipping to the UK wouldn't be more than $20. You'll have gaskets left over, but that is typical when fixing transmissions. Need the correct parts from Jim or www.bulkpart.com etc to do the job right.
_________________
https://imgur.com/user/FisherSquareback/posts
69 FI/AT square Daily Driver
66 sunroof,67,70,71,71,71AT,72,72AT,73 Parts
two 57 oval ragtops sold
'68 Karmann Ghia sold

Society is like stew. If you don't keep it stirred up you end up with a lot of scum on the top! - Russ_Wolfe/Edward Abbey

[Mark Shutt]

I started on the mailing list with the type3.org thing but haven't heard back about my topic I started.. I'll try and get in touch with Jim

Thanks, Mark.
_________________
1968 1600TL Auto build thread, have a look!

http://www.thesamba.com/vw/forum/viewtopic.php?p=6007222#6007222

[Mark Shutt]

by the way, how do I become a member of the mailing list? it keeps saying I'm not a member despite completing registration and needs a moderators approval for every email I send
_________________
1968 1600TL Auto build thread, have a look!

http://www.thesamba.com/vw/forum/viewtopic.php?p=6007222#6007222

[Multi69s]

The play that you are describing is called back lash. There is always a little bit of play between the ring and pinion. To check this reading you will need special tools because it is not a setting that you can go by feel. Did you have any type of whine coming from the rear when you were traveling at freeway speeds? It is possible that since there was trans fluid in the diff, it caused a little bit of teeth wear, and it increased the back lash. However, if the tone of the transmission noise has not changed dramatically, I would not try and reset the back lash. Once you get the diff separated from the case, it might be helpful to throw up a picture of the gear wear pattern. This can give us a clearer idea of what may need to be done.
_________________
69 road Bug 2110
73 Squareback - 2L, T4, Automatic W/ AC
Gone, but many fond memories 69 Baja Bug 2010 - 5 Rib Bus Transaxle
Gone but not forgotten 72 Baja Bug 2010
My builds
T4 into Squareback http://www.thesamba.com/vw/forum/viewtopic.php?t=458944&highlight=
Auto Trans Rebuild http://www.thesamba.com/vw/forum/viewtopic.php?t=516066&highlight=
AC in Squareback https://www.thesamba.com/vw/forum/viewtopic.php?t=...highlight=

[Mark Shutt]

no noise what so ever, will get a picture up tomorrow..
_________________
1968 1600TL Auto build thread, have a look!

http://www.thesamba.com/vw/forum/viewtopic.php?p=6007222#6007222

[one4house]

Mark,

I have been watching. I have had nothing useful to add. These guys are leading you in the right direction. If you have any questions I am just a PM away. Goold luck.

On the list, Jim said that he does have the gasket kits available if you need one. Would be .....$30 american for the kit and shipping to the UK. You would probably only use the one paper gasket out of it unless you needed to replace the 0-rings we were talking about. (large o-ring between the diff and auto unit. Governor cover o-ring)

As far as the seals go, they are standard VW seals. Take the VW part numbers I have listed in the other thread and call you local VW dealer. They still keep some of them. The other numbers I list should be available at a auto parts store. The only seal that is special is the governor seal. You can order it from Summit Racing.

Let me know if you have any other questions.
_________________
My Old 64 Field Find
My Old 66 Squareback
My Old 66 Beetle
My Old 70 Squareback

[Mark Shutt]

I can get the metal clad seals locally no problem it's just the gaskets.. I need the following..

diff to auto unit (and O ring)

diff carrier to diff housing (large one in the bell housing)

2x flange shaft gaskets, early ones with 5 bolt hols in.

what comes in the kit? $50 shipped is fine if it has what I need
_________________
1968 1600TL Auto build thread, have a look!

http://www.thesamba.com/vw/forum/viewtopic.php?p=6007222#6007222

[one4house]

[Mike Fisher]

You have to Forward this email to Mark's email address for him to read it I believe.
https://mail.google.com/mail/u/0/?pli=1#inbox/14575d88a28a2b62
_________________
https://imgur.com/user/FisherSquareback/posts
69 FI/AT square Daily Driver
66 sunroof,67,70,71,71,71AT,72,72AT,73 Parts
two 57 oval ragtops sold
'68 Karmann Ghia sold

Society is like stew. If you don't keep it stirred up you end up with a lot of scum on the top! - Russ_Wolfe/Edward Abbey