How to know if you have gears installed

[Guero]

How do you find out if you have aftermarket gears already? I cruise at 2200 at 80 mph. I was thinking about that because i bought it not to long ago and just thought about it right now.

 

[jonesy]

jack it up and mark the tire and mark the driveshaft and turn the tire 1 revolution and count how many times the driveshaft turns will tell you

 

[Guero]

how many turns for what gears?

 

[HISSIN50]

You will turn the wheel one revolution. The Driveshaft will turn like 2 3/4 times (or 3, 3.5, 3 3/4, just over 4 etc) turns in that one wheel revolution. However many times the DS turns is your rear end ratio.
So if the DS turns ~2.75 times for one wheel revolution, that means you have 2.73 rear gears. You are using the DS and wheel as an extension of the ring and pinion to display the ratio (the ratio is: Driveshaft revolutions to wheel revolutions).

Good luck.

 

[Guero]

so if it turns like 3 close to 4 times it has 3.73

 

[whitesnake1994]

with 3.73s i am turning about 2600 rpms at 80 so i dont think you have them.

 

[BlackVert]

i think stock gears (2.73s) would be turning about 1950 at 80. sounds like you have 3.27s (2300 at 80) ...

 

[Guero]

ill make sure when i drive i think that was the speed and the rpms, could have been 2100

 

[94gts]

with 2.73's im a tick over 2000 at 90 which is gayamnit:

 

[94MustangGT5.0]

with 2.73's im a tick over 2000 at 90 which is gayamnit:

Not for gas mileage!

 

[mricci]

Not for gas mileage!

except if you do a lot of traffic or stop and go driving.

 

[NashSupreme]

my stock numbers

i got a 94 gt, it has stock gears, it runs 2000 rpm at about 75-80 mph i wanna say, so depending on the tire size it shouldnt vary too much, i would say that your gears are stock

 

[Guero]

ok good, ill still make sure.

 

[final5-0]

Trying to compare your mph & rpm to other members values could very well be pretty much useless due to the fact that our tachs can be really far off.

Like JT said, an accurate and simple method is to chalk mark the bottom of a tire and the bottom of the drive shaft and count the turns. That way, you will know for sure.

btw, if your wondering about how many rpm's you will be turning at various speeds with various ratios here is some info for you ... enjoy

http://www.allfordmustangs.com/Detailed/608.shtml

Grady