[Healeys] BN1 Gearbox Leaks

[Michael Salter]

I would agree completely with Eric with respect to the amount of
breathing a gearbox requires however, as I recall, there is one factor
with respect to BN1 boxes that makes them very different from almost any
other box I have worked on and that is the fact that there are seals in
the box, between parts which move relative to each other, which are
constantly immersed in oil. i.e below the normal oil level.
All these other boxes, if the gaskets are in good condition, and they
are correctly assembled usually only leak, if they are going to leak,
while in motion but the BN1 tends to leak even when stationary. 
It is generally considered to be bad practice to design any oil bath
lubricated machine where the shaft seals are constantly subjected to a
head (gravitational or other) of oil pressure. 

Michael
At the cottage
 

-----Original Message-----
From: healeys-bounces+msalter=precisionsportscar.com at autox.team.net
[mailto:healeys-bounces+msalter=precisionsportscar.com at autox.team.net]
On Behalf Of Bill
Sent: August 3, 2007 9:31 PM
To: Healeys
Subject: Re: [Healeys] BN1 Gearbox Leaks

Manual & All,

First let me give you Eric's answer: 

Hey Bill,
The main reason I've not done the o-ring thing is the fact that I've 
known other people who've tried it with very little success.I would 
imagine that the pilot bush condition and the alignment of the bell 
housing to the engine/crankshaft is a factor.As for the gearbox getting 
"pressurized", I doubt that that is the problem as there is very little 
breathing that needs to be done there, as opposed to an engine (engine 
blowby, etc) getting pressurized.Of course, the trans needs to breathe 
due to heat expansion but you would think that once that is accomplished

that it wouldn't need to constantly expel air.Hope this makes sense.
Regards,
Eric Grunden
Absolutely British

I also discussed it with Eric this morn.  I agree that there is very 
little need for relief in the gearbox/OD unit.  He also said:  "What do 
you think the hole in the bottom of the bell housing is for?" And, 
Manuel, I've owned the car since 1978, also never having any evidence of

a leak from there. 

So why did I do it?   Well..........those who know me know I can be 
extremely anal at times.  And you know, there just might come a time 
when I'm in San Francisco and the only place to park the Healey is 
facing down hill on steep California Street.  Hey, it COULD happen and I

wouldn't want all the gear box oil running out, would I?  :-)

Bill Barnett
Santa Ana, CA
'53 BN1 #663

Manuel Formosinho Sanchez wrote:
> Hi all
>
> In my 1955 BN1 I have the original gear box front cover and no leaks
at the
> first motion shaft (I also run on 30W), all the other joints and
gaskets leak
> and I also did a complete overhaul with the best sealants available.
>
> Regards
>
> Manuel FS