Hi, so i have a 2000 Sierra, 4.0 5 speed. I am trying to figure out if the previous owner regeared it. It should have come with 3.73 new as the build sheet and tags on the diff's indicate
I have 31's on it that measure at 30".
By looking at the gear ratio calculator on grimjeeper.com which I have read that I can trust, something does not seem right.
At 2500 Rpm I am running exactly 75 mph
At 3000 rpm I am running exactly 90 mph
In 5th gear. Nv3500 tranny.
With 3.73 I should be going 85 mph at 2500 rpm and 102 mph at 3000 rpm according to the calculator. Can anyone confirm or dispute this?
With 4.11 gears I should be 77 mph at 2500 rpm and 92 mph at 3000 rpm according to this calculator, only 2 mph off of my actual speeds leading me to believe I have 4.11 gears.
My speedo tracks almost exactly with my gps as well as those radar activated speed limit signs that flash my speed at me as I drive by.
What do all of you experienced guys think of this?
Do you agree that the speeds at the given rpm indicate 4.11? Can anyone with similar tranny and tire size advise me if this sounds right?
I am getting ready to go to 33" tires and lockers , and looking into regearing. That is why I was looking at the charts and gear ratio calculators and noticed that something does not seem to add up. I am hoping to find that I already have 4.11 gears.
Would someone regear and leave the 3.73 tags on the diff's?
Thanks in advance for your help! This site is such a wealth of information and knowledge!