In <3491C15F.5806@sprintmail.com>, Kevin Brown wrote:
>I have a '71 MGB that I am putting an overdrive transmission in. I've
>heard that there is a slight difference in length between the overdrive
>and non-overdrive driveshafts (overdrive slightly longer I think). But
>I have also heard that it works fine to use a non-overdrive driveshaft
>with an overdrive transmission -- that the difference in length is
>negligable. Then other peolple say that it doesn't make a difference.
>Does anybody know for sure????
>
...Which is why we need a FAQ. Hey, computer guys, I don't even know
what a web ring is, but we need a FAQ!
That being said, for the 43rd time (sorry, Kevin, not your fault;))
here's the driveshaft lore. The Lindsay Porter book has people all
confused. If you have an early (non-synchro 1st gear) box and a D
type OD, you need a *longer* driveshaft (really!) than the standard
(non-synchro 1st gear) box. If you are replacing an all-synchro
standard box with an all-synchro box with the LH OD, the driveshafts
are *exactly the same*. That's because the four-synchro tranny is
exactly the same length, with or without the OD. However, the length
of rubber-bumper driveshafts is different from chrome-bumper
driveshafts.
The other thing you need to know is that for all chrome-bumper cars,
the speedometer gears are different between the standard and the OD
box, so in theory you need to replace your speedometer. However, if
you are going from a standard all-synchro box to a chrome-bumper
tranny with the LH OD, this difference is trivial (speedo reads about
1% high) and not worth fixing. While the speedo gears for standard
and OD trannies on rubber-bumper cars are the same, they are
*different from* those used in the chrome bumper cars. Bottom line
is that if you are replacing your '71 tranny with a tranny that has a
BLACK LABEL LH OD, you don't need to mess with the speedo. If your OD
has a BLUE LABEL, you will need a rubber bumper speedo.
Easy, eh? Have fun with your OD!
A. B. "Now put this in the FAQ" Bonds
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