speedometer gear at transmission

[garlok]

I need a 22 tooth left-hand lay speedometer drive gear, where the speedo cable connects to the transmission. Car is a 1963 Plymouth Fury originally equipped with a 361, now a 440 but I think it's still the original 727 transmission and driveshaft. I have a 17 tooth gear and the speedometer is 22% fast. I suspect that the rear end ratio has been changed, seller told me it is now a 3.91 and it feels like that is right...fun to drive but I indicate way too fast according to a dyno and GPS. Anybody know who might sell the 22-tooth gear?

 

[Joe Mopar]

Try here.

http://www.jimsautoparts.com/transmission_parts.htm

Scroll down till you find the gears. I've ordered from here before and had no problems.

 

[garlok]

I misspoke, it's the driven gear that I need. The one you can pull out. I'm scratching my head now, everything I see indicates that these transmissions use more like 30-tooth or more gears. The speedo shop says I have a 17-tooth gear!?!? Car came from factory with the 361, I wonder if the 3.91 rear gearing is original, seems pretty deep for a four-door. Maybe whoever put the 440 in also installed new gears to get more performance, that would explain why I'm 22% off on the indicated speed. Anyway, I be having a hard time finding a 22-tooth driven gear.

 

[Stumper]

Man, I can't believe the prices for these plastic gears!! $94 for a 43 tooth gear for the 4:56 ratios .... wow! For $100 you can get a Dum Dum that not only tells you your speed but where to go and how to get there.

 

[hunt2elk]

You probably should take yours out and count the teeth. Common sizes seem to be between 25 and 43. When I was playing with mine, changing the tooth count by 1 would give a mph change of 2. Go to a transmission shop or a older Chrysler dealer and ask if they have any laying around. I was able to pick up several for $5.00 each.

 

[ply64post]

speedo

garlok

If your trans is the original it has acompletly different speeo gear setup
than the I [think 66 and newer] trans!The 65 and older you fasten the gear on
the speedo cable with a clip and the newer gear fits is an adapter and indexed in the tailstock according to the tooth number and the speedo cable threads onto the adapter.I have to go the shop and will check my parts book for a number and tooth gear you need.

 

[Stumper]

You probably should take yours out and count the teeth. Common sizes seem to be between 25 and 43. When I was playing with mine, changing the tooth count by 1 would give a mph change of 2. Go to a transmission shop or a older Chrysler dealer and ask if they have any laying around. I was able to pick up several for $5.00 each.

I know the one in mine now is way off. Speedo shows about 80 at 55 mph. I have 4:56 gears and a Turbo Action 727 tranny. I have it unhooked to keep from breaking something when I step into it Definitely need a gear and the 43 tooth is what seems to be indicated for the 4:56 rear end and the 325/50-15 tires. I just haven't been able to get myself to spring $100 bucks for a little plastic gear.....

 

[ply64post]

speedo

garlok

I checked the 63 parts book and the most teeth listed is 21 teeth
part no.2204 360 gray and with 3.91 it would need an adapter
part no.2291 141 for your application.This is for 65 and before 727
torqueflites,the listing for the 904 with same rear ratio is different by
1 tooth.Hope this will help you.

 

[ply64post]

Stumper

Check this site he lists a used 43 tooth for 59.95 still plenty!!!
I have a bunch of gears and I will check my inventory to see what I
have.





http://www.brewersperformance.com/products.asp?cat=277&pg=2

 

[hunt2elk]

Sorry for the confusion from my previous post. I was working with 1969 models - I didn't know the earlier models used a different style gear. I would still check your local shops to see what they might have.

 

[Stumper]

Stumper

Check this site he lists a used 43 tooth for 59.95 still plenty!!!
I have a bunch of gears and I will check my inventory to see what I
have.

Thanks, let me know if you do. Never thought to put up a want ad but that might be a way to find one reasonably priced. :eusa_boohoo:

 

[garlok]

Man, this is great help, I didn't know about the difference in the 65 and older units...you are a lifesaver. I had to pay almost $200 for a gearshift cable so money is tight but I would like to get this gear.

 

[ply64post]

Stumper

I checked my inventory and I have a nos 43 tooth gear. I don't
want to really question you but with my formula I come up with
a 39 tooth gear for your 4.56 gears and a 325/50-15 tire providing
your tire is 30.35 in tall.Sorry to question but want to make sure you
are getting the right gear from who ever it way be.If you know the height and it is different
than my calculation it can change the teeth number.I have a formula
to figure out what gear you need.The formula is very critical with the
tire diameter and if you have the height I can figure it closer.Unless
what I figured is correct.

30 in diameter tire=39.812 teeth 40 tooth
30.35 in diameter tire=39.35 teeth 39 tooth
30.5 in diameter tire=39.15 teeth 39 tooth

I know all brands of tires can have different heights in the same size.
Hope the info is helpful.

 

[Stumper]

These are MT Street Radials and are 28" OD. I don't have a formula but ran it on a website that sells the gears. Let me know what you calculate as I sure don't want to be off. Thanks!

 

[ply64post]

Stumper

28in tire=42.65 teeth with 4.56 gears.
you can use a 42 tooth or 43 tooth being the closer gear.

 

[oldkimmer]

.......I'll check my stash..........i have several new and used..........kim..........