Lotus Elan

Replacing a Cortina Semi Close ratio withan Elan Wide ratio

PostPost by: Tahoe » Sun Nov 20, 2011 4:03 pm

What is the easiest way to convert a Cortina Semi Clase ratio into a usefull trans for my S2? I currently have a wide ratio and want to install the semi close. Is is easier to take the gearset from the semi close and install it my case, or is it easier to repalce the tail housing? I also understand that the rails need to be replaced, is this true? What else am I missing here? I haven't purchased the box yet, but I've located one which I can pick up tomorrow that was operating properly when removed.

Thanks in advance for the help.
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PostPost by: toomspj » Sun Nov 20, 2011 5:26 pm

I'm assuming that the box you are picking up has the gearlever at the back of the tailhousing, in which case you need to change the housing and the rails. If it has the bolt on remote housing, then you need to remove the remote and swap the rails over.

If you're not used to assembling these gearboxes then probably the most straight forward thing to do is to pull the rails, change the rear housing and replace the rails with those from your elan. You have to remove the rails to remove the housing to swap the gear clusters anyway. I would suggest you change the tail oil seal at this stage.

You need to be careful not to lose the detent pins from the rail mechanism to prevent you from selecting multiple gears simultaneously - there is a pin that runs through the front end of the centre rail, and then there are two larger pins (or plungers) in the gearbox casing at the front. If you keep the main gearbox housing upright while the rails are removed, these plungers should stay in place. If they fall out they can be a pain to get back in again.

The other thing you need to check is the diameter of the input (or first motion) shaft where it goes into the crank spigot bearing. There is a big one and a small one - generally the Elan has the smaller spigot, so if your new gearbox is different you will need to change the spigot bearing.

Good luck - hope the new box is ok!

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