Transmission ratios for a 4-speed Rx-4?
 

Wondering if anyone knows the tranny ratios for a 1976 4-speed Rx-4 coupe. I have been searching for hours with no real luck. Thanks!

I guess I am not the only one! lol.

Here you go:

1st 3.683
2nd 2.263
3rd 1.397
4th 1.000
5th 0.862

By the way, there was no 4 speed tranny that came from the factory in a 76 RX-4. It was either 5 speed manual or 3 speed automatic. If it has a 4 speed in it, it's either not a 76 or the tranny is not original.

That is very interesting, I bought the car from a guy, original owner. The car has 54,000 miles on it as well. When I pulled the engine and transmission, everything looked entirely factory, as did the entire car. Where did you find no 4-speed was offered in 1976? Did they offer it in late 1975?

Ah, there is something else. The car is definitely a 1976, and pretty sure had a 4-speed, as the transmission mounts are much further forward on the chassis. The 5-speed tranny mounts further back, and I dont think somebody would go through all the hassle to make it look like a perfect factory job on the chassis. So, you have me wondering now!

If the intake manifold has the reverse intake runners, then its a 76.

Reverse? Long primaries and short secondaries?

The 76 runners are in reverse order of a typical manifold. The primary runners ran straight to the rear and front plates. Secondaries to the center plate.

This resulted in stronger primaries but weaker secondaries. Perfect for an RX-4 or Cosmo.

This car is without a doubt a 1976, it has the reverse primary/secondary runners, the improved fuel mileage stuff, the americanized front end revison and taillights, and the revised front suspension system using A-arms. Plus it says 1976 on the title.

What's the build date on the car? Now that I'm digging through the cobwebs in my old feeble mind, it does seem like Mazda did use some 4 speeds in some of the early 76 RX-4's and RX-3's.
The gear ratios on the 4 speed are the same as gears 1 through 4 of the 5 speed.
Mazda didn't change the ratios until 1977 when they went to the closer ratio box.

5th is tall on those close ratio trannies.