Speedo, Gears, Ratio Help! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**Palf70Step** · 08-13-2016, 08:21 AM

Yes that is how you can adjust it....is ur speedo slow or fast?

If I remember right you'll need to go to about an 18 tooth if your speedo is slow. If it is fast maybe a 23or 24 tooth.

Normally with a Saginaw/muncie 3 speed, the 21 tooth red gear is used with a 3.73 rear gear, putting the tranny (drive gear) at an 8. Since you have a car 4 speed I am guessing maybe your tranny gear is off (probably 7 tooth). If that is the case and your speedometer is currently 10-12 slow, then the 18 tooth gear (brown I think) should correct it. If your speedo is reading fast, then I am guessing you have a 9 tooth drive gear and a 23/24 willget it back again.

phraza · 08-13-2016, 09:18 AM

Quote:

Originally Posted by Palf70Step

Yes that is how you can adjust it....is ur speedo slow or fast?

If I remember right you'll need to go to about an 18 tooth if your speedo is slow. If it is fast maybe a 23or 24 tooth.

Normally with a Saginaw/muncie 3 speed, the 21 tooth red gear is used with a 3.73 rear gear, putting the tranny (drive gear) at an 8. Since you have a car 4 speed I am guessing maybe your tranny gear is off (probably 7 tooth). If that is the case and your speedometer is currently 10-12 slow, then the 18 tooth gear (brown I think) should correct it. If your speedo is reading fast, then I am guessing you have a 9 tooth drive gear and a 23/24 willget it back again.

You sir are a legend. Thank you so much! Yea its reading 10-12 mph too slow so i'll go for the 18 tooth.

I'm coming up to the US next Friday for a week, so I'll get that part while I'm up there and install it when I get back (will post on here when all done).

Thanks again!

oliver63 · 08-14-2016, 08:24 AM

What part of the US are you coming to? I have some gears I will give you.

Quote:

Originally Posted by phraza

You sir are a legend. Thank you so much! Yea its reading 10-12 mph too slow so i'll go for the 18 tooth.

I'm coming up to the US next Friday for a week, so I'll get that part while I'm up there and install it when I get back (will post on here when all done).

Thanks again!

08-13-2016, 08:21 AM	#1
Palf70Step State of Confusion! Join Date: Jul 2002 Location: Gulfport, MS USA Posts: 47,522	Re: Speedo, Gears, Ratio Help! Yes that is how you can adjust it....is ur speedo slow or fast? If I remember right you'll need to go to about an 18 tooth if your speedo is slow. If it is fast maybe a 23or 24 tooth. Normally with a Saginaw/muncie 3 speed, the 21 tooth red gear is used with a 3.73 rear gear, putting the tranny (drive gear) at an 8. Since you have a car 4 speed I am guessing maybe your tranny gear is off (probably 7 tooth). If that is the case and your speedometer is currently 10-12 slow, then the 18 tooth gear (brown I think) should correct it. If your speedo is reading fast, then I am guessing you have a 9 tooth drive gear and a 23/24 willget it back again. __________________ Bill 1970 Chevy Custom/10 LWB Fleetside 2010 Toyota Tacoma PreRunner SR5 Double Cab - DD Member of Louisiana Classic Truck Club (LCTC) Bill's Gallery Life isn't tied with a bow, but it's still a gift. Live simply. Love generously. Care deeply. Speak kindly. Leave the rest to God!



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