Gearbox Experts: Please help me identify this box!
 

Hey chaps,

I picked up this 5-speed manual for my RX-2 project a few weeks ago, and I've just gotten around to looking at it closely and I've discovered it has a "park" gear to the left of where first gear is located.

Selecting "park" results in a loud click (presumably as some pin is inserted in some shaft somewhere) and the tailshaft locks completely, yet you can still turn the input shaft.

See photos - there are three sender units. One (on the body) is for reverse, one near the shifter is for neutral, and the other is for this "park" gear. I've confirmed this using a multimeter as well as visually.

I guess I'm just wondering what it's out of, and how rare this "park" mechanism is? I've only come across it once before, although to be honest I've had little contact with RX-4's and RX-5's. I guess it could be out of an early Luce/Cosmo sedan too?

Also, has anyone ever driven a car with this "park" gear? Is there a light on the dash indicating when it's locked up? Could you only start the car in park or neutral? I'd really like to know how it all functions.

Finally, does anyone know how much further back this shifter will be compared to the original 4-speed location on a 1974 Mazda RX-2 sedan?

Sorry for the novel, any help very much appreciated, it's driving me crazy!

http://img402.imageshack.us/img402/1954/frontx.th.jpg
http://img25.imageshack.us/img25/6937/sideisn.th.jpg
http://img24.imageshack.us/img24/7171/fulln.th.jpg
http://img23.imageshack.us/img23/3702/underneath.th.jpg
http://img22.imageshack.us/img22/5079/backiyl.th.jpg

i'm not really an expert on anything automotive, but my little .02 cents is find the vin if the tranny has one on it. then if it does, try to search it on google, one of the first few numbers should be the model.

Thanks man, the only numbers on the box are "78" and "54" stamped on the main body, then "01628" in small numbers stamped below the shifter on what appears to be a dedicated recess. I'm assuming the latter is the production number, but I have no idea what the former are.

At a stretch "78" might be the year of production, which really means it could be anything from RX-2, RX-4 or RX-5.

I guess I'm just hoping someone will come along and tell me which production car had this "park" gimmick.

well if you go with that 78 is year of production, i'm guessing its from a Luce since that was sorta marketed as a luxury car and it came with a 13b. i'm still searching for you on cars with a park gear [seems like its partially an automatic =P]
But i also found out that the Mazda REPU came with a 5 speed in 1978 so that also could be a possibility [if they are sold in NZ]

It could be Luce, I agree. It could also be HB Cosmo. Don't worry about where it was sold, it's definitely been imported. Cosmo/Luce/RX5 etc were never sold domestically in New Zealand.

looks like the tranny i'm running that's from a 74 rx4. if 78 is the yr stamp, it's probably from the rx5, cosmo here, or a repu.

rxtasy3, does your box have this park gear?

I have a US Cosmo, and it doesnt have a park gear.

Are you sure it is a park gear or could there be a problem with the trans inside, so the shifter fork isnt engaging?

Just a Idea

Cheers - it's definitely a park gear. I've taken off the rear sender and shone a flashlight in there, it's engaging the switch when park is selected.

So if it's not US Cosmo, it's either RX-4, JDM RX-5 or HB Cosmo.. or perhaps REPU.

The park mechanisem in the few auto's iave taken apart are always in the back of the tranny, basicly inside the tailshaft housing. Park being enganged doesnt lock up the input shaft, just the output shaft.

Yeah the locking sound it makes sounds like it's something in the tailshaft housing. And that's exactly what happens, the tailshaft locks but the input can be turned freely.

My 80 model JDM Cosmo 5 speed came with a park gear, if that helps.

Thank you!

So it's definitely at least JDM Cosmo. Now, if only I could find out how many they made..

didn't really read that far into ur post. i've never heard of such, so no mine doesn't have it.

Just thinking about it, if it is JDM Cosmo it might explain things better. The RX-5 had a disk rear end, and perhaps they added it as an alternative to the emergency brake. E-brakes tend to work better on drum rear ends, perhaps the fledgling disk rear ends had issues and Mazda added it for a bit of extra safety?

TQX Cosmo box - they had a torque converter on them (yes on a manual 5 speed). NZ wreckers were bringing in heaps in the 90's. I had one in an RX4 at one stage, and the gear sets are good to rebuild a standard RX4/5 5-speed as they had better ratio's. The shifter comes up on a weird angle in most cars... see them on TradeMe every month or so.

Cool, thanks for the info - so you're saying the gear lever might sit too far forward in an RX-2?

Could sombody please post what the ratio's are in this tranny?

Should be the same as late model RX-4 twin dizzy, or the piston 121;