hayduke

the sticker on the inside of the door is gone.
i jacked up the rear and 2 turns of the tire equals about 4.6 turns of the drive shaft. this is for a 94 v6 5 speed.
on my other truck i turn the tire twice and get the 8.2 turns of the driveshaft like im suppose to.
any help is appreciated.

881stGenRunner

look on the metal plate in the engine bay up against the fire wall. There will be a long code and that code tells you your gears, engine, tranny, x-case, and anything else. All you havet to do is find a website that breaks it down for you, but they are easy to find.

GSGALLANT

I've answered this quite a few times here, so a search would have helped you out, but I'll post it again.

The easiest way is to:

For an open differential:
Leave the tranny or transfer case in neutral, lift one of your rear tires off the ground and leave the other on the ground. Mark the driveshaft with a piece of tape or a dab of liquid paper so you can count the revolutions. Get a friend to help you rotate the tire while you lay under the truck and count the number of revolutions the driveshaft makes.

When you get set up, get your friend to rotate the tire exactly 20 times. Count the number of times the driveshaft rotates. Devide the number of driveshaft revolutions by 10 to get your ratio. (If you have 4.100 gears, the driveshaft will rotate 41 times... 41/10=4.1)

For a locked differential:
Leave the tranny or transfer case in neutral, if the rear is locked, lift both rear tires off the ground. Mark the driveshaft with a piece of tape or a dab of liquid paper so you can count the revolutions. Get a friend to help you rotate the tires while you lay under the truck and count the number of revolutions the driveshaft makes.

When you get set up, get your friend to rotate the rear wheels exactly 10 times. Count the number of times the driveshaft rotates. Devide the number of driveshaft revolutions by 10 to get your ratio. (If you have 4.100 gears, the driveshaft will rotate 41 times... 41/10=4.1)

This way, you don't have to guess as to whether the driveshaft rotated 4.6 times or 4.7 times or 4.8 times. There are no partial revolutions if you do it this way.

bruzer

I just went through the same thing you did and I found that most of the 2nd gens 4 runner's that had the V6 with the 5 spd trans had 4.56's stock.

hayduke

a locked diff will spin both tires the same direction and an open diff will spin them opposite correct?
i did search and that was where i came up with my method of testing.
it worked when i did it on my truck 8.2 turns with one turn of the tire.
the unknown gear truck the driveshaft only turned about 4.56 for one turn of the tire.
one thing that might have messed me up was i had the whole rear end off the ground and not just one tire. didnt think about it possibly being a locked diff either.
thanks for the responses.
--adam

MonsterMaxx

If the truck came with 31" tires or was an SR5 it has 4.56, if it came with tiny tires it's 4.11
Automatics came with 4.88.

If you jack only one tire, you are spinning thru the spyders and will get a 2x multiplier

hayduke

its not an sr5 but it does have 31's but i dont know if they or stock or someone just slapped them on there.

when i jacked the whole rear up i made sure only one tire was spinning, the one i had marked.

DudeBud

not true my 90 sr5 has 4.10s

GSGALLANT

That is why I said to rotate the wheel 20 times, then divide only by 10.

GSGALLANT

Sort of... for a locked diff, when you spin one wheel forward, the other will rotate in the same direction at the same speed... so you're right on that. For an open diff, when you have the rear jacked up on both sides and you rotate one wheel, things will take the path of least resistance. Say with an automatic for example, if you are in park, then the driveshaft won't rotate at all, so when you rotate one wheel forward 1 revolution, the other wheel will rotate backwards 1 revolution. If you're in neutral, and the driveshaft is free to rotate, you may not get 1 full revolution out of the opposite tire because the driveshaft may rotate a bit also (you are right that the opposite wheel will still rotate in the opposite direction, though)

Look at an open differential this way: The driveshaft will rotate X times (where X is the gear ratio) the average number of rotations that both of your rear wheels make.

For example, say you have 4.56 gears. While you are in park with both wheels off the ground, and you rotate one wheel forward 1 rev, the other rotates backwards 1 rev, and the driveshaft doesn't move.

So your driveshaft rotates 0 revolutions / 4.56 = 0. That means the average # of rotations your rear wheels have to make is also zero. The average of 1 revolution (forward) plus negative 1 revolution (backward) is zero, so that works.

Example 2: With 4.56 gears, while in neutral with one wheel on the ground and one wheel up, when the driveshaft rotates 9.1 revolutions / 4.56 = 2. That means the average # of rotations your rear wheels have to make is also 2. The wheel on the ground rotates 0 times, so the one in the air will rotate 4 times (4+0)/2 = 2.

mastacox

My '92 SR5 4Runner came with 225's, but once I put 31's on it the speedometer is dead on... and it has 4.30's.

Basically trying to make sweeping generalizations for the gear ratios just won't work, you need the axle code.

Gator

Just wanted to thank you for posting this up, you actually saved me a load of money. The sticker on my truck shows that I should have 3.91 gears, but I went out and checked using your method just out of curiosity and found that I am actually running 4.56 gears. Since I was planning on jumping up to 33's soon, I had already bought a locker and was waiting to get gears before I put them on.

Once again, thanks.

Richard