[Healeys] New Project BN1 3 speed Laygear]

Mr. Bill bn1 at pacbell.net
Sat Jul 11 20:58:04 MDT 2009


(Bounced.  Here's a cut down one.  B)

Hi Rich & List,

I thought there would be more discussion about this but perhaps you had 
more off List.  Or maybe I'm one of the few die hards who still love the 
3-speed with overdrive coupled to Lempert gears.

I am surprised that you're starting with the laygear.  I've had two 
boxes break on me and did not damage the laygear either time.  Maybe I 
am just quick to clutch when it goes "Bang".  Both occurred during WOT 
in second (3rd) and broke the teeth adjacent to one of the three oiling 
holes.  That seems to be the weak point.  Please see the attached 
picture which will be stripped for the List.  I've been looking a long 
time for a NOS 1B3697 (which I believe belongs to the gear set you're 
speaking of) because every used one I have found, no matter how good it 
looks, will jump out of gear when backing off.  We even had a Club 
member go to Autojumble during Goodwood and he was almost laughed at. 

I think you might have a much larger market if you first started with 
that gear and then went to the laygear.  I know I would be happy to take 
a couple of them off your hands!

Bill Barnett
'53 BN1M


Rich C wrote:
> Hello all,
>
> I have been working with a brilliant machinist who is into CNC machining, CAD
> programming, and specializes in gear cutting.
> He's looking for challenges in his business and asked me what's needed. I
> handed him a later BN1 laygear with a shattered 2nd gear (3rd gear
> internally), explaining that this seems to be their weakness and if I had good
> laygears and 2nd gears, I could reassemble a number of BN1 gearboxes and put
> them back into service.
> He happily took this as a personal challenge and has come back to me 4 weeks
> later with quotes and a metallurgy report on the original.
> It seems that the original is very hard, too hard in his opinion, with a
> Rockwell reading of 64 to 66 which is likely why when they let go, they simply
> shatter like glass, taking the other gear with it.
> Anyway, making the complete laygear new is no problem. Machining and
> installing the bronze inserts in each end would be included as part of the
> process.
> Of course as with anything, the more pieces made, the cheaper it will be.
> I am no machinist, but I'll quote what he has said. He gave me 3 prices for
> different hardness qualities.
>   
<SNIP>

[demime 1.01d removed an attachment of type image/jpeg which had a name of 1B3697 BN1 gear.jpg]


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