Subject: Re: [Healeys] OD Longevity

From: Jean Caron <[email-masked]>
Date: Sun, 15 May 2016 18:37:51 +0000

Bob,
I am sure you will get some good answers from people that have them rebuilt but I can tell you that mine in my BN6 was rebuilt at 67,000 miles. Having said that, my car is parked about 5 months of the year for winter and when I purchased it it had sat for 11 years before that. When I first put it on the road I changed the oil and that was it, drove it about 6 more years and it gave me some trouble on a trip to Georgia, got the oil changed in it near Chicago, continued on my trip down and then back home and rebuilt it that winter. All was well except it was pretty full of sludge and stuff in the side overdrive piston area. I replaced the bronze thrust washers and have run about 30,000 miles since without issues.

Jean
________________________________________
From: Healeys <[email-masked]> on behalf of Bob Spidell <[email-masked]>
Sent: May 15, 2016 5:04 PM
To: Healeys
Subject: [Healeys] OD Longevity

Listers,

I've always been a bit in awe of the Laycock De Normanville overdrive
units as fitted to our Austin-Healeys.   To me, it's a wonder of
engineering elegance and simplicity--well, except for the electricals,
maybe--and as it's an 'axial' design there are no significant side loads
to wear out layshafts/gears and bearings. However, all things have a
life span and I'm wondering what is the typical life for the A-Series--I
believe that's what's in my BN2 and BJ8--OD units under 'normal'
(non-racing) usage?  The unit in my BJ8 has over 190K miles on it and
AFAIK it has never been overhauled, and I'd hate for it to die on one of
my long road trips as we inevitably spend hours on straight stretches of
interstate highways (I do have a 3.54 rearend, which would make things a
bit more tolerable, but the 22% reduction in RPMs is hard to beat;
except maybe with 28%).  I've used Redline MT-90 in the gearbox/OD for
the last 40-50K miles or so and--some will think this is blasphemy--I
only change it out every 20-30K miles (I don't buy into the 'use
non-detergent oil so the all the sludge will drop to the bottom' theory,
when I change out the syn oil I note the oil is clean and light-colored,
and that there is finely-ground brass shake suspended in the oil but it
is so fine you can't feel any grittiness at all if you rub it between
your fingers; and note that some of the best greases--lithium,
molybdenum, etc.--are finely ground soft metals suspended in oil).

Anyway, what's the collective wisdom on this: run 'em until they quit,
or rebuild them at 100/200/300/?K miles as a precaution?

As usual, TIA.

Bob

ps.  I'll keep using 74W-90 in the diff as recommended by y'all.
_______________________________________________
Archive: http://www.team.net/archive

[email-masked]
http://autox.team.net/mailman/listinfo/healeys

_______________________________________________
Archive: http://www.team.net/archive

[email-masked]
http://autox.team.net/mailman/listinfo/healeys

---

From: "John Spaur" <[email-masked]>
Date: Sun, 15 May 2016 21:45:44 -0700

Now that you have asked, your OD will fail soon. However, if will fail
sooner if you are anxious for the answer verses not really caring.

John
'62 BT7

[email-masked]

---

From: Oudesluys <[email-masked]>
Date: Mon, 16 May 2016 09:20:39 +0200

If it ain't broke, don't fix it!!!!
If it is worn it will not operate properly any more and you will know. 
Nothing desasterous is going to happen. So leave well alone if all is well.
Kees Oudesluijs

Op 15-5-2016 om 19:04 schreef Bob Spidell:
> maybe--and as it's an 'axial' design there are no significant side 
> loads to wear out layshafts/gears and bearings. However, all things 
> have a life span and I'm wondering what is the typical life for the 
> A-Series--I believe that's what's in my BN2 and BJ8--OD units under 
> 'normal' (non-racing) usage?  The unit in my BJ8 has over 190K miles 
> on it and AFAIK it has never been overhauled, and I'd hate for it to 
> die on one of my long road trips as we inevitably spend hours on 
> straight stretches of interstate highways (I do have a 3.54 rearend, 
> which would make things a bit more tolerable, but the 22% reduction in 
> RPMs is hard to beat; except maybe with 28%).  I've used Redline MT-90 
> in the gearbox/OD for the last 40-50K miles or so and--some will think 
> this is blasphemy--I only change it out every 20-30K miles (I don't 
> buy into the 'use non-detergent oil so the all the sludge will drop to 
> the bottom' theory, when I change out the syn oil I note the oil is 
> clean and light-colored, and that there is finely-ground brass shake 
> suspended in the oil but it is so fine you can't feel any grittiness 
> at all if you rub it between your fingers; and note that some of the 
> best greases--lithium, molybdenum, etc.--are finely ground soft metals 
> suspended in oil).
>
> Support Team.Net http://www.team.net/donate.html
> Suggested annual donation  $12.75
> Forums: http://www.team.net/forums
>
> [email-masked]
> Unsubscribe/Manage: 
> http://autox.team.net/mailman/options/healeys/[email-masked]
>
>
>

[email-masked]

---

From: Alan Seigrist <[email-masked]>
Date: Mon, 16 May 2016 18:02:19 +0800

--===============4428961895676759606==

--001a1144018253af770532f2b8f1

Yep, the OD on my BJ8 has probably seen 150K or even 200K miles (not
sure).  Never touched it, still works like a champ.  My original 32% OD on
my early BN1 is similar... never rebuilt.

My feeling is they are quite similar to old three speed automatic
gearboxes, and as long as you treat them with respect, and keep oil in
them, they will last forever.

On Mon, May 16, 2016 at 1:04 AM, Bob Spidell <[email-masked]> wrote:

> maybe--and as it's an 'axial' design there are no significant side loads to
> wear out layshafts/gears and bearings. However, all things have a life span
> and I'm wondering what is the typical life for the A-Series--I believe
> that's what's in my BN2 and BJ8--OD units under 'normal' (non-racing)
> usage?  The unit in my BJ8 has over 190K miles on it and AFAIK it has never
> been overhauled, and I'd hate for it to die on one of my long road trips as
> we inevitably spend hours on straight stretches of interstate highways (I
> do have a 3.54 rearend, which would make things a bit more tolerable, but
> the 22% reduction in RPMs is hard to beat; except maybe with 28%).  I've
> used Redline MT-90 in the gearbox/OD for the last 40-50K miles or so
> and--some will think this is blasphemy--I only change it out every 20-30K
> miles (I don't buy into the 'use non-detergent oil so the all the sludge
> will drop to the bottom' theory, when I change out the syn oil I note the
> oil is clean and light-colored, and that there is finely-ground brass shake
> suspended in the oil but it is so fine you can't feel any grittiness at all
> if you rub it between your fingers; and note that some of the best
> greases--lithium, molybdenum, etc.--are finely ground soft metals suspended
> in oil).
>
> Anyway, what's the collective wisdom on this: run 'em until they quit, or
> rebuild them at 100/200/300/?K miles as a precaution?
>
> As usual, TIA.
>
> Bob
>
> http://autox.team.net/mailman/options/healeys/[email-masked]
>
>

--001a1144018253af770532f2b8f1
Content-Transfer-Encoding: quoted-printable

<div dir=3D"ltr">Yep, the OD on my BJ8 has probably seen 150K or even 200K =
miles (not sure).=C2=A0 Never touched it, still works like a champ.=C2=A0 M=
y original 32% OD on my early BN1 is similar... never rebuilt.<div><br></di=
v><div>My feeling is they are quite similar to old three speed automatic ge=
arboxes, and as long as you treat them with respect, and keep oil in them, =
they will last forever.</div></div><div class=3D"gmail_extra"><br><div clas=
s=3D"gmail_quote">On Mon, May 16, 2016 at 1:04 AM, Bob Spidell <span dir=3D=
"ltr">&lt;<a href=3D"mailto:[email-masked]" target=3D"_blank">bspidel=
[email-masked]</a>&gt;</span> wrote:<br><blockquote class=3D"gmail_quote" st=
yle=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Liste=
rs,<br>
<br>
I&#39;ve always been a bit in awe of the Laycock De Normanville overdrive u=
nits as fitted to our Austin-Healeys.=C2=A0 =C2=A0To me, it&#39;s a wonder =
of engineering elegance and simplicity--well, except for the electricals, m=
aybe--and as it&#39;s an &#39;axial&#39; design there are no significant si=
de loads to wear out layshafts/gears and bearings. However, all things have=
 a life span and I&#39;m wondering what is the typical life for the A-Serie=
s--I believe that&#39;s what&#39;s in my BN2 and BJ8--OD units under &#39;n=
ormal&#39; (non-racing) usage?=C2=A0 The unit in my BJ8 has over 190K miles=
 on it and AFAIK it has never been overhauled, and I&#39;d hate for it to d=
ie on one of my long road trips as we inevitably spend hours on straight st=
retches of interstate highways (I do have a 3.54 rearend, which would make =
things a bit more tolerable, but the 22% reduction in RPMs is hard to beat;=
 except maybe with 28%).=C2=A0 I&#39;ve used Redline MT-90 in the gearbox/O=
D for the last 40-50K miles or so and--some will think this is blasphemy--I=
 only change it out every 20-30K miles (I don&#39;t buy into the &#39;use n=
on-detergent oil so the all the sludge will drop to the bottom&#39; theory,=
 when I change out the syn oil I note the oil is clean and light-colored, a=
nd that there is finely-ground brass shake suspended in the oil but it is s=
o fine you can&#39;t feel any grittiness at all if you rub it between your =
fingers; and note that some of the best greases--lithium, molybdenum, etc.-=
-are finely ground soft metals suspended in oil).<br>
<br>
Anyway, what&#39;s the collective wisdom on this: run &#39;em until they qu=
it, or rebuild them at 100/200/300/?K miles as a precaution?<br>
<br>
As usual, TIA.<br>
<br>
Bob<br>
<br>
ps.=C2=A0 I&#39;ll keep using 74W-90 in the diff as recommended by y&#39;al=
l.<br>
_______________________________________________<br>
rer" target=3D"_blank">http://www.team.net/donate.html</a><br>
Archive: <a href=3D"http://www.team.net/archive" rel=3D"noreferrer" target=
=3D"_blank">http://www.team.net/archive</a><br>
Forums: <a href=3D"http://www.team.net/forums" rel=3D"noreferrer" target=3D=
"_blank">http://www.team.net/forums</a><br>
<br>
<a href=3D"mailto:[email-masked]" target=3D"_blank">[email-masked]=
eam.net</a><br>
<a href=3D"http://autox.team.net/mailman/listinfo/healeys" rel=3D"noreferre=
r" target=3D"_blank">http://autox.team.net/mailman/listinfo/healeys</a><br>
<br>
s/[email-masked]" rel=3D"noreferrer" target=3D"_blank">http://autox.t=
eam.net/mailman/options/healeys/[email-masked]</a><br>
<br>
</blockquote></div><br></div>

--001a1144018253af770532f2b8f1--

--===============4428961895676759606==
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

[email-masked]

--===============4428961895676759606==--