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patrick lovering
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Hi all, just notice there is a Sunbeam Rapier gearbox with a laycock overdrive on ebay uk at the momment, I realise this might be not much use to you in the States, but just thought I'd mention that I have made this conversion to my Mk2 and it works well, the extra gears really relax the engine on motorways and effect quite a saving in fuel.
The gearknob mounted overdrive switch from a Triumph Stag works a treat and looks pretty cool too.
Patrick

Frank Schwartz
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Too bad such things never appear here in the US....

patrick lovering
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they're pretty rare over here too, I think the Laycock overdrive units were also fitted to Jaguar, Austin Healy, Alpine, Hillman, Triumph, MG.

Greg Fletcher
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Ages ago, Richard Appleyard in the UK did an article for our club newsletter on how to do this conversion. I'll have to dig that out. Sounds worthwhile, but I remember it being expensive back then and some of the parts where already hard to get. It did require a fair amount of fiddly work and fabrication.

patrick lovering
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The overdrive is just a bolt on affair and electrically activated via the stag gearknob switch, the cables running up a supplementary metal pipe I braised onto the gear stick. you are also supposed to drill and tap a cut out switch that stops you selecting reverse whilst in overdrive. I did'nt do this out of laziness and as a result made the gearbox make some horrible noises a few times! 

Spaceman
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So do you still have that article, I just bought a Sunbeam Rapier OD, and wonder what parts I need to get with it? Do I need the long shaft sticking out of the Rapier 4 speed?

noomg
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Unless your J/H is a 4sp I'm not sure why you'd want to try to adapt what sounds like a very rare gearbox which is going to require a lot of engineering and fabrication to make it work. The Getrag 5sp is a very nice gearbox and works really well in the J/H. If you do have a 4sp I think it would be much easier to find a Getrag and do a swap, I think you'd be pleased with the results.

subwoofer
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The Getrag has a taller rear end, so effectively it already has an overdrive compared to the 4-speed. Top is 1:1 for both boxes.

--
Joachim

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Got my Sunbeam Rapier OD home, and from watching the rebuild video on the Sunbeam page, it doesn't look too daunting. I am thinking the only difference is the collar around the input shaft for the clutch throw out bearing to sit on. So can they just be swapped over? Are any parts required? The spline is the same, but don't know about the end, if it will fit the 907 crank end.



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