GrnStang00

Okay i have a problem. I am selling my mustang... not happy about that for one. When i bought the car the original owner told my father it had something done to the rear end. Something that made the acceleration faster. I told him it was the gears, now we're not completley sure of this. I dont wanna take it into a mechanic or whatever to have them check. Is there anything i can do to check for myself and see if i have different gearing?

bleau

Jack up the back of the car and place a line on the driveshaft.
Have a buddy rotate the rear tires and count the amount of times the driveshaft turns.
That should get you close enough.

GrnStang00

Okay thanks, what should i be looking for? Like as far as what should happen if they're aftermarket?

Rusmisel01GT

Open your shifter console and see if there is a speed calibrator sitting there.. if not, then he got a tuner to fix the speedometer... if he never used a tuner to fix it, and there is no speed calibrator in the shifter console... then your speedometer is off... if your speedometer is not off by 5-10 mph on the highway, and you dont have a speed calibrator and no tuner, then he probably lied to you.

GrnStang00

My shifter console? Its a 5 speed.. you mean my boot?

bleau

Everything Rusmisel told you plus if the drive shaft rotates more than 3.2 revs you have a gear i/e 3.73, 4.11

blstoff

the best way is what bleau said .
3-1/4 revolutions of driveshaft to 1 revolution of tire = 3.27
3-1/2 revolutions of driveshaft to 1 revolution of tire = 3.55
3-3/4 revolutions of driveshaft to 1 revolution of tire = 3.73
alittle over 4 revolutions & you have 4.10 or 4.30

Tapeuup

What he means is rotate the rear wheel 1 time and count the driveshaft's rotation.

bleau

Thanks Tapeup, kinda missed an important step in my instructions.