Gear Ratio RPM issue

[shiftinda93z]

am I stupid in the fact that I am wondering what is going on in the thread? The "turn test" as it was reffered to is basically fool proof. my driveshaft turns 4.10 times for every 1 revolution of the tire, and I do have 4.10 gears lol. Not sure how a 4.10 could be any different????? Likewise, any other gear??? there could be issues if you turn the tires, such as having a torsen diff, but that's another issue in itself... just turn the driveshaft...

[wezeles]

its easy on a posi to tell but on an open i could see it being a tad harder still marking it up with chalk is the easiest way to find out without pulling the cover off... even so if it does have something other than stock i guess it would be a good idea to catch which brand gear you have in there and then just replace the seal and add some nice new synthetic gear oil when you put it back together... with the tranny fluid and rear end oil swapped to sythetic i got an extra 2mpg and you can feel how much smoother it is... so its not like its going to hurt anything to pop the cover off just to take a peek..

[zspot98]

Easiest way to check is either the door tag. Or if you have a steel driveshaft you have 2.73's.

[Orange Terror]

Well, solved the mystery. Just got home and checked the door. GU5 is the code, which is the performance axle option. So I have 3.23 gears, which also explains the aluminum driveshaft. The math doesn't quite work out with the calculator, but now that I know what it is I guess that really doesn't matter.

Anyways, very pleasantly surprised to find this out!!!!

[JoeliusZ28]

i think you should be lower than 2800 at 80 mph though... my truck turns like 2300 at that speed... granted it has taller tires and 3.73s, idk how that would balance out.

[zspot98]

i think you should be lower than 2800 at 80 mph though... my truck turns like 2300 at that speed... granted it has taller tires and 3.73s, idk how that would balance out.

Nope, I'm running 2.73's and turning 2100 rpm's @ 80 mph. It's 3.23's.
Jasen, you should have just looked @ the driveshaft from the start.

[Orange Terror]

Nope, I'm running 2.73's and turning 2100 rpm's @ 80 mph. It's 3.23's.
Jasen, you should have just looked @ the driveshaft from the start.

I knew the driveshaft was aluminum, I just didn't know till I did some research yesterday that it meant I had 3.23's. Oh well now I know, one less thing I have to change now!!

[9T8W66]

Just wanted to Add that those Axle Calculators sometimes need your gear ratio from the trans. 3rd gear is 1 to 1 on Auto's 4th is like .76 so that may explain the differences.