Hi Randy,
In my experience small chips out of the teeth have little effect on the
operation of the gears themselves. The removed chips however can be
devastating for the laygear bearings which is why I like to add an
additional magnet into a Healey gearbox.
As far as serviceability of gear teeth is concerned you need to look
very carefully at the thrust faces of the gears to try to determine if
the gear profile is correct. The profile is the cross sectional shape of
the tooth. Often gears will wear in such a way that they develop a divot
or hollow on what was originally a curved gear face. If this has
occurred the gears really should not be used as they will both be noisy
and will probably cause their mating gear to wear rapidly.
That said however if I was building an "economy" Healey gearbox for my
own use I would be fairly tolerant of the 1st gear condition because I
never use 1st gear and the only time that that gear gets any use is in
reverse.
Michael Salter
www.precisionsportscar.com
-----Original Message-----
From: dicksonr@uwm.edu [mailto:dicksonr@uwm.edu]
Sent: Sunday, April 11, 2004 7:28 PM
To: Michael Salter
Cc: 'Tracy Drummond'; healeys@autox.team.net
Subject: RE: You be the judge Photos and Chipped gears? How much is bad?
After viewing Tracy's gears I have wondered about the condition of my
gears and
whether they are in need of replacing or not. I'm currently rebuilding
a BJ-7
gearbox. I have a new laygear. The old first gear has one or none
chips (I
forget) and the reverse gear has two chips. Basically, they look like
Tracy's.
Since I have a new laygear I was wondering about the compatibility and
if it is
ok for an older gear to mesh with the newer. Perhaps the presence or
absence
of chips of chips is not the answer but the degree of case hardening
still
present on the gears. For me, this is all a balance of economics (I'm
certainly not rich and less money for parts = more money for beer),
labor, and
how much I will drive my Healey anyway. I'm just trying to get a
feeling of
what one can get away with in a gearbox and still get a smooth working
and
reliable gearbox for many thousand miles. Thanks!!!!
Randy Dickson
Healey Archaeologist
63 BJ-7
Quoting Michael Salter <msalter@precisionsportscar.com>:
> Hi Tracy,
>
> Despite the poor assembly by the P.O. (or his local tranny shop more
> likely) you are in pretty good shape. I suspect that something was
wrong
> with the positioning of the selectors or how they were secured to the
> selector rods which caused the loss of the detent balls and springs.
If
> you assemble the box correctly you should resolve that. The bell
housing
> and overdrive adaptor have little pads in them where the ends of the
> selector rod touch which limit the travel of the rods, these were
> probably missing. Also if the Bellville washers and spacer shims were
> missing around the main bearings things can go a bit pear shaped.
>
> IMHO none of your gear damage is bad enough to condemn those parts
> unless you have lots of money to burn. The running faces all look to
be
> in good condition despite the chips which are relatively minor.
>
> I'm glad the person who did the lock wiring doesn't work on any
aircraft
> that I might be flying (or perhaps he does!!).
>
> I don't think what you have identified as wear on the selector is
> actually wear. As I recall they were made that way to provide
sufficient
> clearance.
>
> The wear on the synchro ring is almost certainly due to the same thing
> that caused the detent balls to drop out.
>
> That detent ball is meant to be hiding between the selector rails (it
is
> the interlock system to prevent you going into 2 gears at the same
> time). There should be a ball between each of the rods and a little
> plunger in the center rod which shuttles back and forth.
>
> There is something wrong with your photo entitled..
>
> "Theres a hidden problem. The three detent springs and balls for 3rd
and
> 4th wre in the bottom of the case!!"
>
> I think you have the 1 / 2 gear assembly on backwards. Don't put it
> together that way!!
>
> Also, interestingly the axial alignment of the gears in the photo .
>
> "Laygear (Had new layshaft and roller bearings :-)"
>
> Does not look good. Either you didn't have the main shafts pushed all
> the way in or the main bearing shins and washers are incorrect.
>
> There is almost no wear on the selector forks where the selector lever
> engages, indicating that this box has had very little use
>
> New gaskets and seals, a circlip and some roller needles, at least one
> synchro ring (check the three ears on the other two for wear),
probably
> bearing shims and Belleville washer(s), 5 - 6 hours work and you will
> easily make it to Mt Hamilton.
>
>
> Michael Salter
> www.precisionsportscar.com
>
>
>
> -----Original Message-----
> From: owner-healeys@autox.team.net
[mailto:owner-healeys@autox.team.net]
> On Behalf Of Tracy Drummond
> Sent: Sunday, April 11, 2004 10:00 AM
> To: healeys@autox.team.net
> Subject: You be the judge Photos (Transmission questions)
>
> Thanks in advance to all who responded to my transmission rebuild
> questions.
> Well I dug into it yesterday and was suprised at what I found.
>
> I took some photos and ask those in the know if what I found:
>
> A> Correlates to difficult shifting into 3rd and 4th (I think it
does).
> B> Can this laygear be reused?
> C> Can these 1st and reverse gears be reused?
>
> Thanks in advance oh wise and learned ones.........
>
> http://www.wavewired.net/~tracy/transmission/transmission.htm
>
> Tracy (trying to get back on the road for Dream Machines - will miss
Mt
> Hamilton tour)
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