Topic: finding back gear ratio

[naneak]

i got gearing in the read but str8 front is stock.. how do i find out the rear end ratio without  spending money..
and exactly what would i need to put gears in the front end?

[Toyonrocks]

There are only a few options out there. ie.. 4.10, 4.88. 5.29. I'm not sure what higher gears come stock but you should be able to google it or read other links on this site. You should be able to eye ball it and figure out what you have. It's really really easy if the axle you're checking has a locker or posi in it. Lift the axle you want to figure out. If it's not locked or posi hold 1 side still, and lock the hubs in front axles. Make a mark on the pinion and dif. Then make a mark on the drum and dust cover or rim and use a point on the axle. Turn the pinion and count how many times the pinion passes your mark before the rim or drum returns to your mark. The pinion revolutions in relation t 1 full tire rotation is your ratio. Good luck.

[3toys]

If its stock gearing it could be 4.10, 4.56, 4.88.  I don't know exactly what you're working on, but that's the common 4wd gear ratios, and it depends on year and model.  I would guess 4.10 since its the most common. 

Chock the wheels in front, jack up the rear(one side), , and if you're not locked, rotate the driveshaft and count the number of driveshaft rotations to two rotations of the tire (or one rotation and multiply by two, but its more accurate for two exact revolutions). 

If you're locked, jack up both rear tires, count driveshaft rotations to one revolution of the tire.  That'll be your ratio.  About four driveshaft turns is 4.10, 4.5 turns is 4.56, etc...

Please follow all safety precautions so you're not run over by your own truck.....

[Moose404]

pull the diff and count how many teeth the ring gear has then divide it by how many teeth are on the pinion. for example i have two different diffs for my rear(one welded one not) and one of said diffs has 41 teeth on the ring & 10 on the pinion and the other has 37teeth on the ring & 9 on the pinion but they are both 4.10 ratio.  this is the most acurate way i can think of to find your diff ratio i hope it helps

P.S. Mark a tooth it makes it easier to count ;P

[Moose404]

and as far as putting gears in the front though you need to figure out what you got in the rear then find a ring and pinion gearset that matches and replace your stocks with them.  id take mine to a differential shop to have the gears installed though so they can set the backlash properly i think its around 80$ for the install last time i checked

[Toyonrocks]

Finding a complete third is nice for sure but building one isn't terribly hard. You can buy a dial indicator set up from harbor freight for $30 to set back lash. The hardest part is getting the crush sleeve to collapse.