Dshon

I recently bought a used 2007 GT and was wondering if there is an easy way to find out if he changed the factory gears?

baddog671

Lift your car off the ground
Position a rear wheel so that the valve stem is at 12 oclock
Put a mark on your driveshaft
Rotate your wheel a full 360 degrees

Watching your driveshaft, if it rotates around 3.5 times to the wheel's 1 turn, it's 3.55.

Diabolical!

The easiest way is to support the rear axle on jackstands with the car in neutral and follow this procedure. Paint a white dot on the lowest point near the rear of the driveshaft. Mark a white dot on the lowest point on one of the rear tires. Lay under the rear of the car and watch the driveshaft while you have someone else slowly rotate the marked tire EXACTLY one rotation. Count how many full rotations the driveshaft makes and then estimate how far the white dot travels past the final full rotation. It's not precise, but with a limited number of gear options, it makes estimating pretty easy. For example, if the driveshaft rotates approximately 3.5 times, then you have 3.55 gears. If it rotates approximately 3.75 times, then you have 3.73 gears. A little over four times and you have 4.10s... You get the idea.

Diabolical!

In the time it took me to type that, baddog said it much simpler, lol.

shoeys08dkcandygt

Read the sticker on the rear diff. White sticker on back of diff

Dshon

thanks guys for all the input. I needed to know so when I go to request a bama tune they are going to ask me all the mods to tune from and I would hate to assume they are still stock gears when he had other mods done.

Rainson

other than what other member stated, you may also write down the rpm number from AM website of each gear set, drive it on the road and check. most recognizable is 2nd gear at 55mph..

baddog671

You also said to put PAINT on the WHEEL

2005Redfire6

That would work if the gears weren't changed... I have 4.10s and it still says 3.31

baddog671

Those stickers won't last very long, lol. When I took my diff plate off to change the fluid, I cleaned the plate off with Purple Power and although the sticker remained, bye bye ink letters.