How many teeth do i need for speedo Gear.
Thread Starter
Heel & Toe
Joined: Oct 2003
Posts: 15
Likes: 0
From: lake orion mi
How many teeth do i need for speedo Gear.
Well, The results are in
I curently have 19 teeth on the speedo gear that goes in the trans and I know something is wrong. I took the cable apart and re-greased it and now I need to figure out the hard part. I drove 2 miles at 60 MPH and it took 2.27 min 2.28 min and 2.31 min I also took a reading at 1 mile tha was 1.14 min can any one tell me how many teeth I need on that gear or how do i figure it out.
I thank you all in advance,
Geoff
I curently have 19 teeth on the speedo gear that goes in the trans and I know something is wrong. I took the cable apart and re-greased it and now I need to figure out the hard part. I drove 2 miles at 60 MPH and it took 2.27 min 2.28 min and 2.31 min I also took a reading at 1 mile tha was 1.14 min can any one tell me how many teeth I need on that gear or how do i figure it out.
I thank you all in advance,
Geoff
Race Director
Joined: Oct 2002
Posts: 12,065
Likes: 2
From: Smalltownville Michigan
Cruise-In 5, 6 & 10 Veteran
St. Jude Donor '09
Re: How many teeth do i need for speedo Gear. (geoff4961)
It all depends on your transmission, speedo gear and tire size if you have changed any of them, the gears will be different. If I remember right, mine (77 vette, 350 auto and 3.08 gears with 225-70-15 tires) is a 38 or 39 tooth. They are differentiated by color and teeth, but you probably already know that. I used to have a link to the colors and teeth counts. If I find it, i'll IM it to ya. :seeya
Le Mans Master
Joined: May 2002
Posts: 5,086
Likes: 787
From: Lebanon Township New Jersey
Re: How many teeth do i need for speedo Gear. (geoff4961)
I recently changed rear ratio and used the following method to correct the speedometer:
Your speedo reads 60 and it takes 1.14 minutes to cover a mile. Therefore your speedo is reading high because you must be going less than 60 since 60 equals 1 mile per minute. You need to add teeth to the driven gear to slow down the speedo. Since you are now 14% off (1.14 min per mile), you need to multiply 19 teeth now by 1.14. That works out to 22 teeth. Thats what I would try. Zip has gears for about $7 each.
Your speedo reads 60 and it takes 1.14 minutes to cover a mile. Therefore your speedo is reading high because you must be going less than 60 since 60 equals 1 mile per minute. You need to add teeth to the driven gear to slow down the speedo. Since you are now 14% off (1.14 min per mile), you need to multiply 19 teeth now by 1.14. That works out to 22 teeth. Thats what I would try. Zip has gears for about $7 each.
