Gearbox Identification... What do I have?

[Alpine_Ian]

Hi guys... Been a while since my last post, but the S2 Elan project is moving along nicely. I've been working on the engine and drive train and the body work is just about done. Should be finishing the project this summer!

Here's my question. I just finished rebuilding the rear diff, which is a 3.9:1 ratio (standard). I have the gearbox that came out of the car and an additional gearbox that I picked up seperately after I purchased the car.

Both are Ford 2000E 4 speed boxes.

Box A: This one that came out of the car has a black plastic driven gear which is meant to be used with a 3.55:1 rear diff. It also has no reverse light switch or tapped hole.

Box B: This one was purchased from an individual who told me it came from his S2 Elan and had very little use. He replaced it shortly after he purchased the car for a racing type gearbox of some sort. It has a plastic driven gear that looks blue/green and a reverse light switch.

I can't determine if the gear from Box B is blue or green, but it looks more green to me. If that were the case it would be a 3.77:1 gear, not the 3.9:1 blue gear that I want for my car.

From this I need to determine if the box that came out of my car is even the correct box for an Elan... the starter pinion cover has not been flattened out like it should be from the factory. The 3.55:1 drive gear isn't matching my rear diff ratio and from what I understand, the 3.55:1 was used on Special Equipment cars... which I don't think my car is (how would I know?).

I need to decide which gearbox to use and if the blue/green drive gear is blue or green!



Can anyone help me make sense out of this? I'm concerned that the box that came from the car (Box A) is really a Cortina box without Lotus gears. I think Box B is from a S4, not a S2.

Advice?

[Dave-M]

Can't help with the speedo gear but, to check if it's 2000e or standard Cortina is easy.
Put it into first gear and count the turns of input to output.
Check the manual for the gear ratio of first gear and you have your answer. If it's more than 3:1 it's a cortina (from memory)
Regards
Dave

[Alpine_Ian]

Ok, thanks. I tested them both and Box A & Box B are 3:1 in first. Safe to say they are both Lotus gears sets. Do you agree?

The plastic drive gear will only affect the spedometer, but would be nice if someone could confirm what is up with this? Why would I have a black gear for a 3.9:1 rear end? Maybe gearbox has been swapped out at some point... I really have no way of knowing. I can use the blue/green gear from other trannny if anyone can positivly identify it as blue and not green. I've never seen a blue gear to compare with. Thanks!

[Dave-M]

OK. 2000e is 2.97 first gear so looks like you are OK on that
3.9 diff should use a green gear with 24 teeth.
Count the teeth and see what you have
Regards
Dave

[Alpine_Ian]

Ok, I have 24 teeth on the blue/green gear.. let's call it green. The black gear has 23 teeth.

This is interesting... Brian Bucklands book calls out the green gear as a 3.77:1 and the blue 3.9:1. Hummm...

Where did you get the information you gave to me? I have a factory WSM, but I loaned it to my buddy and don't have it here to reference at the moment.

Based on what I have learned from you tonight, I can put my green gear into my original gearbox and be in good shape. Problem solved!

Thanks!

[1964 S1]

Hello Ian, according to a book I have, an SE S2 would have to be between numbers 26/5282 and 26/5810.
I think later SE's had an improved "iron cast" exhaust manifold and trim emblems but an early SE could be tricky to identify.
I have two different spare trans and could sell one if you need a third!
Eric

[john-c-elan+2]

They say speedo driven gear: 3.9 diff - 25 teeth - blue
3.77diff - 24 teeth - green
3.55diff - 23 teeth -black

[Alpine_Ian]

Humm... looks as if I really do need the blue gear... that or a 3.55 diff!

Anyone have a blue drive gear for a 3.9? Hate to buy another gearbox just to get a drive gear.