62-65 speedo gears

Have a push button TF and need a Green 20 tooth speedo gear for a 3.73 rear. Has a brown gear in there now from a desert gear. Anyone repop or know of a source. And other cost effective options to get speedo close for road trips.

I would try eBay & you might google speedometer shops & put an ad in here & on FABO

also early b body site used to have a classified that had some advertised..

http://www.1962to1965mopar.ornocar.com/welcome.html

Brewer's is another source, but the prices are getting up there and inventory is limited.
I can tell you that the 20 and 21 tooth gears are like hen's teeth. I have been on the watch for one for years.
The 19 tooth gear in my 64 Belvedere is green in color. I think the 20 tooth gear is a different color.

a 20 tooth with a 3.73 rear by itself won't be accurate. any axle ratio lower (higher numerically) than a 3.55 will require a ratio reducer. there was never any combo's made that was perfectly accurate. the easiest way is a 17 tooth with a .80 ratio reducer. 19 and 20 tooth were used mostly in 3.23 gear cars. 21 tooth was for 3.55 rear and 3.91 gear cars used a 21 tooth with a .80 reducer. I use an 18 tooth with a .90 reducer for a 3.23 gear and 28" tall tires. speedo is close but not perfect.

^^^ That's what I was thinking, a ratio reducer, I have one but no idea how well it works but it seems simple enough. I ain't opened it up but I think just 2 gears at a right angle in a box.

I run the OE 3.23 gear gear in my 65.Now has 3.91s i know that speedo is about 20% fast.Just compensate for it.It was way off when i ran 4.88s on the street.Also the gears are different than later models which makes them even harder to find.Rocky

it's difficult to get the speedo's exact. there were only 6 different pinions made and there is a 5% difference between them. chances are whatever you do you'll be a couple of percent off. a ratio reducer will be necessary to get close.

Problem is where do you get a ratio reducer. I used to know a speedo shop that I got new cables for my 64 300 from that could make them, but that was in 1988. Now days, who knows?

Lewt good info (I gotta a couple of early ones up coming)

I got my reducer from Imperial Services years ago, but I think they're out of business now. the Good Guys Gazette had a speedo service ad for odd stuff but I haven't gotten the gazette in a few years. I was told that they were used on Fargo truck stuff. maybe goggle them? they're the only solution.



I found this in an older gazette. United Speedometer Service, Inc. 951-684-0292. give them a call. a stock cable won't work with the reducer, but a 1966 cable will.

Imperial Services still has a web site....

http://www.imperialservices.net/

Don;t think that phone number is accurate anymore.

http://www.usande.com/contact.html

I think they may have been the one I dealt with way back when.

yes, but i don't have much faith in those guys. way too many horror stories about those "services" floating around to make me uncomfortable giving them any money for the items they have, or at least advertised.
there are things i am interested in, but i won't take a chance.

Will one of these adapters work?

https://transmissioncenter.net/product-t...933-product_tag

No, they're thread-on adapters, the '62-'65 uses this type.

I've never looked that close to see if it could be done, but.
Would it be possible to use the stock speedo trans gear/cable assy, and put the ratio adapter on the other end of the cable, then have a short cable to connect the ratio adapter to the speedo head? Similar to the way mopar did the cruise control.

Sure, it could be done. Need two custom cables though that's the easy part.

DO NOT USE Imperial Services! Sold to Steve Chattel who is an outright thief! Sent $415 for a ratio adapter that never got sent. He will just quit answering your calls after a while. Turned him in to FBI fraud division, THEN he called me. But NEVER got the part. Hard to deal with thieves out of state, but god help me the next time I go to Michigan....

What you need to do is go GPS signal to mechanical speedometer. Then gear ratio and tire size becomes irrelevant. Change either anytime!


GPS link

^^^ trick!

Yes, they make inline reducers that have threaded input/output or crimp in the cable. Speedo shops use them to get the cable speed dead on when there's no room at the trans output.

Here's a nifty idea to keep the stock speedo and drive it with a GPS input.

https://www.speedhut.com/ecommerce/product/2585/SPEEDBOX™-GPS-VSS-to-Mechanical-Drive-Speed-Converter

Use the link three post up...

bought used/never tried it. Stewart Warner made in US of A.

What ratio is that one? They made hundreds of different ones.

It has 1.2020X stamped

I opened it up & the teeth count is (in to out/upper left to lower right): 11 teeth/18 teeth on the middle idler/14 teeth. EDIT I ain't sure if this (procedure) is right but 11/18 is .61111 and 18/14 is 1.28511 and 1.28511-.61111 = .6746 (underdriven???). MORE EDIT With more work if my math is right it will reduce the tooth count 27.27%, speeding up the speedo that % amount