Rear End Gear??
Thread Starter
Burning Brakes
Joined: Oct 2001
Posts: 842
Likes: 3
From: Woodruff SC
St. Jude Donor '10
Rear End Gear??
I have a 77 L48. How do you know what gear ratio is in the rear? Heard there's a code on the housing, but what means what? Any other way to tell?
Thanks for all the help!!!!!!! :cheers: :chevy
Thanks for all the help!!!!!!! :cheers: :chevy
Le Mans Master
Joined: Jan 2000
Posts: 8,918
Likes: 27
From: New Hill NC
Re: Rear End Gear?? (DP77Vette)
The code is on the flange between the rear cover and the main housing right under the bottom. You can always lock one wheel and turn the drive shaft and count the turns it takes to make one revolution of the wheel. This will be the ratio. 2.75, 3.08, 3.55, 3.70 turns etc.
Instructor
Joined: Dec 2001
Posts: 113
Likes: 0
From: Grand Rapids MI
Re: Rear End Gear?? (DP77Vette)
try this formula:
tire diamater inches x rpms at 60
-----------------------------------------
20178
this will give you the rear gear ratio. if you are at 3000 at 60 with a 26 inch tire, it comes out to 3.87- possibly a 3.90 gear. you will need an accurate speedometer and tachometer to use this method though. also, it will only work at 1 to 1 transmission ratio. use "drive" if you have an overdrive trans
Matt
[Modified by Matt M, 4:12 AM 1/9/2002]
[Modified by Matt M, 4:18 AM 1/9/2002]
tire diamater inches x rpms at 60
-----------------------------------------
20178
this will give you the rear gear ratio. if you are at 3000 at 60 with a 26 inch tire, it comes out to 3.87- possibly a 3.90 gear. you will need an accurate speedometer and tachometer to use this method though. also, it will only work at 1 to 1 transmission ratio. use "drive" if you have an overdrive trans
Matt
[Modified by Matt M, 4:12 AM 1/9/2002]
[Modified by Matt M, 4:18 AM 1/9/2002]
