Speedo Gears

[87ttypeV8]

i have recently changed my rear end and my speedo is all jacked up...

ok can some one please help me

i HAD a 2.56 rear end with 215 64r15 tires (stock)
i just got a new eaton gear rear end 3.73
same tire size...

just wondering what gears to put in and what colors (OR PART NUMBERS FOR THE CORRECT GEARS)

someone please help no trans shop will help unless they service the car and that will be 90-120$ depending on what shop i called

PLEASE HELP!

 

[77 cruiser]

take a look

This wil get you headed in the right direction.

http://www.tciauto.com/tech_info/speedo_gears.htm

Jim

 

[87ttypeV8]

i dont know the number of drive teeth or driven teeth as posted at that web site...

thanks for the help but i dont know what to do with it

 

[78oldscutlass]

Start out with the 10 tooth drive gear. The Only person I know to have the green 10 tooth gear is PTS. Since you have a pretty small tire, the 10 tooth will help to slow down the speedo the most.

Grab a measuring tape and measure the height of the tire. Then plug all the numbers in the formula to get your gear.

For example: with a 10 tooth drive, 3.73's and 25" tall tire, you will need the 30 tooth driven gear to make the speedo right. You can get most of the driven gears through a GM dealer, but sometimes the aftermarket is was cheaper on them.

Driven gears 35-45 do not exsist, thought for some reason it is listed on the site?

 

[MeanBuicks]

Doh!

Originally posted by 78oldscutlass
Driven gears 35-45 do not exsist, thought for some reason it is listed on the site?

Hey, thanks for reminding me about that. That error has been there for a while but I kept forgetting to knock those off of there. Should be gone now.

 

[WE4]

10 tooth green and 29 tooth driven yellow will do...

 

[87ttypeV8]

thanks for the replies... now how do you install them

 

[Nordbert]

speedo gear install

The drive gear is on the governor, which is inside the pan and under the cover with 4 bolts which have 13 MM heads. The
governor can fall apart while you change the gear, so make sure you make a detailed drawing or take a lot of digital pictures of it.
I took mine apart in a clean pan, and I'm sure glad I did! A little
petroleum jelly was used to hold the balls in place during assembly. Torque the cover bolts to 18 lbs./ft. If you get the drive gear from GM, it will come with a governor cover gasket. I could
e-mail you an end view of a governor if you need it.

 

[87ttypeV8]

governer is necessary in a transmission or just "should" have it in...

what would happen without it?

i think i may check out another trans shop cause i dont want to be messin with anything that i could kill my car with if i "F" it up

 

[Nordbert]

Don't worry!

It's really not hard to change that gov gear, you just have to be CAREFUL and CLEAN. There is help on this board if you need it.
It's just a post away! The governor controls shift points and
its gear drives the speedometer cable.