Toyota gearbox speedo drive comparison

[Flash]

I'm in need of some guidance from the Toyota Brain's Trust.

I'm searching for a speedo correction device for my G54 gearbox. Castlemaine Rod Shop offers two models. One they say is for a Celica gearbox and the other for a Supra gearbox.  I'm not sure what the specific models are but I'm assuming they are the ones that are popular with the Hot Rod boys, possibly W series but I might just be showing my ignorance.

Does anyone know if either of these will fit my G series box ?

 I haven't seen these specific devices in the flesh but I assume they just screw in to the existing speed drive much like the old VDO units that I have used on TH350 auto gearboxes in the past.

Thanks for reading.

[Roman]

From what I've seen there are two main types of speedo drives for Toyota boxes. 

"big gear" versions like W series box have say 31-35 teeth on them. 

https://www.google.com/search?q=g+series+gearbox+speedo+drive&sxsrf=ALeKk03yxNEvrg-dI2VonKFBQkNfv9cu0A:1619952729153&source=lnms&tbm=isch&sa=X&ved=2ahUKEwiUleWX6qrwAhXPzTgGHVGrAUQQ_AUoAXoECAEQAw&biw=2560&bih=1273#imgrc=Bp1diltzu6K6xM

Then "small gear" versions which have say 10 or 12 teeth on them. 

https://www.google.com/search?q=g+series+gearbox+speedo+drive&sxsrf=ALeKk03yxNEvrg-dI2VonKFBQkNfv9cu0A:1619952729153&source=lnms&tbm=isch&sa=X&ved=2ahUKEwiUleWX6qrwAhXPzTgGHVGrAUQQ_AUoAXoECAEQAw&biw=2560&bih=1273#imgrc=HSnVSm-EeZ3feM


These are probably the two variations being talked about, W50 series or W55 series 

So just see what your one looks like. 

With the big teeth ones they look to be universal even to FWD boxes etc. 

[Flash]

Thanks heaps for this info @Roman, it now makes a lot more sense. I'll pull my drive out today to see what it looks like.

[Flash]

Armed with the info provided by @roman I pulled my speedo drive today.

Looks very much like the unit in Romans first link, but it has 21 teeth as borne out by the marking on the top of the nylon gear.

So I'm guessing that my unit may be similar to that out of a W55 through to W59 gearbox.

A bit of Googling has revealed that the W55 was used in Celicas from 1981 to 1985 and the W57 was used in both the 21R Celicas and the Supra MK2s, so I'm left wondering why Castlemaine Rod Shop offer different converters for the Celica and Supra boxes.

Think I'll give them a ring in the morning to seek some clarity. 

[Carsnz123]

Similar to ford owners referring to Tudor and Fordor, that's just illiterate boomer speak. The W50 has been referred to as a Celica box for yonks and same with the W58 being called a supra box. probably the two most common vehicles they could be robed from. I was under the impression that the gear/worm on the output shaft of the gearbox stayed constant and the speedo drive gear varied when changing speedo ratios. sorry have no idea where the G box fits in the picture but id take a guess and say it would be similar to the W58 gearbox as far as speedo drive goes. 

 

Edit: just looked at the listing on their site and my guess is the corrector goes inbetween the speedo drive and cable. So really the info they're after is the thread size and core size of the cable. probs best to email them. 

[Flash]

Thanks @Carsnz123, I think that you are on the money in terms of how the Hot Rod Boys would differentiate the boxes. I'll drop them an email today.

[Flash]

Mystery solved. They refer to the steel cased gearbox as a Celica and the aluminium cased one as a Supra.