gear ratio
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Freshman User
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gear ratio
i have a 94 f-250 , 4x4. at 70 mph iam turning 2100 rpm.my current tire size is 265/75/r16. the truck calls for 235/85/r16. the original paper work on the truck says it had a 355 gear. but i have paper work showing that the rear end was canged. i am beliving maybe it is a 411 that is in it now. i know i acn take the cover off and cout the teeth, but off the top of your heads, what do yall think may be in there?
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Joined: Apr 2004
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At 70 mph, 32 inch tires, .71 OD top gear, 4.11 axle, you should turn 2144 rpm.
A 3.55 changes this to 1853 rpm.
Go here, second calc down, go further down for tire size calc.
Novak Conversions - Gearing & Gearing Math for Jeeps
Sounds like 4.10 or 4.11 to me.
A 3.55 changes this to 1853 rpm.
Go here, second calc down, go further down for tire size calc.
Novak Conversions - Gearing & Gearing Math for Jeeps
Sounds like 4.10 or 4.11 to me.
Freshman User
Joined: Apr 2006
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From: channahon, Il
This is the way I would check it too.
Put a chalk mark on the wheel/drive shaft and count the rotations of the driveshaft per 1 rev of the tire. If you dont have limited slip then make sure you mark both tires and keep them in sink with each other while turning the drive shaft.
