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Overdrive??

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vagt6

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Hello, all. Has anyone installed a Laycock overdrive unit in their Midget/Sprite/frogeye??

I've not heard a lot about it, was wondering if and how a Dtype or Jtype might fit.

Input, please. Thanks!
 
A very innovative conversion. I especially like the way he widened the gearbox tunnel with a scissors jack. /bcforum/images/%%GRAEMLIN_URL%%/hammer.gif

So, it's do-able. I was surprised that the stock propshaft fit the J-type. Very interesting.

Thanks for posting!
 
...and it sounds like a more reasonable swap than the 5 speed. What is the o/d ratio of the j type?

John
 
Jtypes came in several flavors with most providing a 25% reduction. Some had 27% and were used on Volvos, mostly the 240 turbos in the late seventies.

I installed a J type in my MK II (1970) GT6 and it literally transformed the road performance of the car (3.89 rear end). I highly recommend either the Dtype or Jtype units. Both are dependable (the Jtype is a bit more robust than the earlier, Dtype model) and capable of 200,000 miles or more when maintained properly. However, if you intend to consistently thrash the car (i.e., frequent racing or autocrossing), OD may not be for you.

The key, I think, is to carefully inspect and overhaul the OD unit BEFORE it's installed. Then, you can drive it with confidence for many miles. The J type provides OD in 3rd and 4th gear, effectively rendering a six-speed gearbox. There's nothing like switching the gearbox lever in 3rd and 4th gear into overdrive. Most passengers today have never seen one operate and it's always a thrill for the uninitiated.

Each to his own, of course, but knowing what I now know about the Laycock overdrive units, I'd NEVER install a modern five speed gearbox in any LBC. OD is just too much fun!

And, it's period-correct. /bcforum/images/%%GRAEMLIN_URL%%/angel.gif
 
YEAH!! What ~HE~ said!
 
vagt6 said:
A very innovative conversion. I especially like the way he widened the gearbox tunnel with a scissors jack. /bcforum/images/%%GRAEMLIN_URL%%/hammer.gif

So, it's do-able. I was surprised that the stock propshaft fit the J-type. Very interesting.

Thanks for posting!
Click to expand...

The conversion works on the 1500 because it's the same gearbox the Spitfire 1500 used, and it did offer an overdrive thanks to a bigger body. So, the non-overdrive 1500 gearboxes just have a tailpiece that makes up the same length as the overdrive unit. No driveshaft changes needed.
 
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