Gears

[Roush150]

Hello all...I've got a question about checking the gears on my Lightning. I just bought it about 2 weeks ago and the only mod that I know its got is 4# lower, sct, and other minor mods. Is there a way I can check if its got gears without taking off the diff cover? The speedo is off thats what brought the question up.

 

[simshahh]

3.55's for a 2000 and older. Anything later 3.73

 

[simshahh]

Also check your tire rotations/mile. I think stock is 733 r/m. And make sure you have the right size stock tires on there. 295/45's.

 

[Roush150]

Thanks for the reply sim but thats not the question. I know what gears they're suppose to come with my problem is trying to figure out if mine has aftermarket gears. I'm running the 295/45 F1's

 

[simshahh]

Thanks for the reply sim but thats not the question. I know what gears they're suppose to come with my problem is trying to figure out if mine has aftermarket gears. I'm running the 295/45 F1's

If there is a way to do it without taking off the cover, Ill be damned. Fade knows everything. When he comes in here eventually, he will just tell you what you have. Other than that, good luck!

 

[FleeMan]

I have 3.73's and at 60mph im at about 1900 RPMs. If you are noticably higher then that, rpm wise, then you have 4.10 gears

 

[Roush150]

Cool thanks sim.

Yeah I'am higher than that. If I remember correctly its somewhere between 22-2500.

 

[FleeMan]

then you more then likely have 4.10's

 

[castellscl]

Also check your tire rotations/mile. I think stock is 733 r/m. And make sure you have the right size stock tires on there. 295/45's.

You can find out by doing kinda what this guy said. I'll see if I can find it for you. Should be able to find it on google under some 4x4 site.

http://www.btc-bci.com/~billben/reargear.htm

http://www.brightcove.tv/title.jsp?title=716031903&channel=537308532

 

[BlackBolt9]

Jack up the rear end in neutral. Rotate the tire 1 revolution and estimate how many revolutions the driveshaft makes. The ratio of those two numbers will give you the gear ratio. It isn't extremely accurate but it should be able to get you close enough to guess which you have.

Edit: Not sure how the diff is going to act so you may have to hold the other tire stationary or rotate them together.

 

[Derek@Amazon]

jack up rear ,put in in "n" ,rotate tires...

watch the drive shaft. drive shaft should turn just over 4 timres for 4.10's and a 1/4 under for 373's

 

[Roush150]

Well looks like I have 4:10's. I think I'm going to go down to 3:73's