what gears do i have?
03-28-2010, 10:30 AM
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what gears do i have? I have a 1999 TA A4. The guy I bought the car from had the rearend replaced by a local shop, and has no idea what gears they used. I was told that you can tell what gears you have by your mph at 2000rpm's. Also, i heard wheels and tires can be a factor, so...
I have 17's in the front and 18's in the rear. tires are 275/40/17 and 295/35/18.
On the freeway under normal acceleration, i reach 2000rpm's right at about 70mph. Any idea what gear i have?
I have 17's in the front and 18's in the rear. tires are 275/40/17 and 295/35/18.
On the freeway under normal acceleration, i reach 2000rpm's right at about 70mph. Any idea what gear i have?
03-28-2010, 10:43 AM
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You can do it that way or....
jack up the rear end
put the car in neutral
make a mark on the pinion so you can count how number of revolutions of the driveshaft
make a mark on the tire to count number of revolutions
turn the driveshaft one revolution by hand
Count the number of times the wheel turns
if it turns 2 3/4 times, you have 2.73s
if it turns 3 1/2 times....3.42s etc
jack up the rear end
put the car in neutral
make a mark on the pinion so you can count how number of revolutions of the driveshaft
make a mark on the tire to count number of revolutions
turn the driveshaft one revolution by hand
Count the number of times the wheel turns
if it turns 2 3/4 times, you have 2.73s
if it turns 3 1/2 times....3.42s etc
03-28-2010, 11:17 AM
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I have a 1999 TA A4. The guy I bought the car from had the rearend replaced by a local shop, and has no idea what gears they used. I was told that you can tell what gears you have by your mph at 2000rpm's. Also, i heard wheels and tires can be a factor, so...
I have 17's in the front and 18's in the rear. tires are 275/40/17 and 295/35/18.
On the freeway under normal acceleration, i reach 2000rpm's right at about 70mph. Any idea what gear i have?
I have 17's in the front and 18's in the rear. tires are 275/40/17 and 295/35/18.
On the freeway under normal acceleration, i reach 2000rpm's right at about 70mph. Any idea what gear i have?
Last edited by redws618; 03-28-2010 at 09:19 PM.
03-28-2010, 11:30 AM
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03-28-2010, 11:56 AM
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So will going to 3.73's from 3.23's be worth it? Also, are GM gears any good? This guy want's to sell me some GM 3.73's out of an '88 S-10. He says they are in great condition, and the pics he sent me look pretty good. He only want's $80 shipped for them...
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03-28-2010, 11:59 AM
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I am M6 so I have 3.42s and I wanted 3.73s but now I'm considering 4.10s after everything I've heard.
03-28-2010, 12:01 PM
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3.23-3.73 no you will not set the world on fire.
do like i do,if your not totally sure on the gears in your rear end pull the cover!
If the cover is off the differential, count the number of teeth on the ring gear and the pinion gear. Divide the number of ring gear teeth by the number of pinion gear teeth. The resulting number is your gear ratio. (For example, a ring gear with 39 teeth and a pinion gear with 11 teeth: 39 divided by 11 is 3.5454...; these are 3.55 gears)
2nd if the rear cover has never been touched "open your glove box" and take a look, the data sheet will tell all.
do like i do,if your not totally sure on the gears in your rear end pull the cover!
If the cover is off the differential, count the number of teeth on the ring gear and the pinion gear. Divide the number of ring gear teeth by the number of pinion gear teeth. The resulting number is your gear ratio. (For example, a ring gear with 39 teeth and a pinion gear with 11 teeth: 39 divided by 11 is 3.5454...; these are 3.55 gears)
2nd if the rear cover has never been touched "open your glove box" and take a look, the data sheet will tell all.
