Transmission Leak Question

Hi all,

I am finally having my first garage-worthy problem with my 1988
760GLE.

I've been going through transmission fluid at a rate of about 2-3
litres per week (!!!) and I finally got under the car this morning to
see what the problem was. A leak, of course. It seems sprayed all over
the area where the drive shaft connects to the transmission and the
joint there is soaked in fluid so my diagnosis is that this seal has
given out. There is some mention on the Mitchell CDROM that a plugged
vent can also cause fluid to be forced past the seal so there are two
possible causes that I need to investigate.

First question: What is the actual proper term for this seal? I know
where the differential meets the driveshaft there's a "pinion seal"
but what's the seal at the other end?

Second question: Is there some way I can determine if the vent is
plugged without getting under the car again? And if the vent is
plugged would you advise that, once the seal has been compromised, I
should replace it anyway?

The local garage I'm looking at trying for the first time (at Mount
Pleasant and Davisville in Toronto...anyone have a review?) told me I
could bring it in tomorrow morning so I'm mainly looking for some
intelligence before walking in there.

Thanks for reading this,
blurp

 

Here's another possible issue: both the owner's manual and the Haynes
manual specify Type F transmission fluid (and that's what it's been
getting). The Mitchell CDROM, however, says that "If Type F is used
the clutches may be damaged".

Any thoughts?

blurp

 

That's the transmission output shaft seal. The output shaft is
supported in a bushing, not a ball or roller bearing. What usually
happens is the bushing wears, then the output shaft moves up and down
too much, and the seal fails. You'll probably need to have the bushing
replaced as well as the seal.

Your transmission should be using Dexron, not type F.

--
Mike F.
Thornhill (near Toronto), Ont.

Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)

 

Thanks, Mike.

There are few words to describe how stupid I feel right now and, based
on my actions, most of them would be an insult to people with
diminished mental capacity.

My Haynes manual says to use Type F on cars up to 1983... my 240 is an
83 and I'm so used to looking for that qualifier that I must have
mixed it up and misread that THIS car (a 1988) took Type F.

Oooops. I've poured in (and through) about 6 litres of Type F and one
bottle of Lucas Transmission sauce (or whatever it's called).

So what damage am I likely to have done or what damage am I likely to
have accellerated? I'm getting the seal looked at tomorrow, should I
get the flush/fill right away to avoid any further damage between now
and then?

Thanks again,
blurp

 

You probably didn't do any damage so quickly, just flush it out with the
right stuff and it'll be fine (aside from the seal and bushing of course)

 

If it hasn't been misbehaving, don't worry about it. The Lucas auto tranny
stuff is pretty good, and maybe that helped the situation. Drive it gently
to the shop and you should be okay.

Mike

 

From what I understand, and I'm far from an expert on these things,
using Type F instead of Dexron causes the clutches to engage harder and
release slower. So I guess what could happen is you have more clutch
"overlap" when one clutch is being engaged and another disengaged. As
far as know this only happens when shifting from reverse to a forward
gear or vice versa, and since the transmission is (should be) stopped
this would be minimal. So there shouldn't be any problem, but I'd
certainly flush with Dexron, if you don't notice any shifting problems,
then you haven't likely done any damage.

--
Mike F.
Thornhill (near Toronto), Ont.

Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)

 

Well that's all very reassuring. The car really worked fine except
when the fluid level got too low from dripping out over night and the
1st gear would barely engage at 3000 RPM in the cold. Once topped up
it runs fine so I'm hoping it'll stay that way once the seal/bushing
are replaced and I take it to Mr. Lube for a flush.

Thanks all!
blurp

ps. Mike F, you're in the Toronto area, do you do all your work or do
you take your Volvo to a shop? If so which one? Thanks.

 

I do all my own, and have a friend that I occasionally help out that
lets me use a hoist in his shop.

--
Mike F.
Thornhill (near Toronto), Ont.

Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)

 

Well the official verdict is that it's not just a seal but an entire
sleeve (or bushing) and two seals (probably at either end of said
sleeve) to the tune of $286. From what I read on a cached Brickboard
page that seems about right.

It's interesting, though, that a vibration I felt while driving (which
was dismissed by another mechanic as a loose heat shield) may well
have been play in the driveshaft as described on the BB FAQ. I look
forward to what may be a slightly quieter ride.

I'll post when it's all done, thanks for all the usual great input!

blurp