I see that everyone upgrades there gears by going higher. If Im correct, higher gear ratios make your pinion gear smaller. And dont allow as many teeth to contact the ring gear. Therefore if you were actually upgrading, it would be a downgrade. The only benefit would be increased speed, and maybe a longer clutch life. Is this really a trade off? I asked around and found that 3.90 vs 5.56 has a tooth and a half difference. I may be wrong, but that is quite a bit. It wouldnt matter for offroad, as 4low is geared low enough to pull a truck through sand with all 4 tires flat. So do you guys do it just for the easier town driving. Is it really worth it?

 

if ur going with larger tires...(i.e. 35's 37's...somethin like that)...then u will want to go with 5:29's or 5:71's...the gears just get your powerband and gas mileage and all that back into basically stock...with the larger tires...ur mileage is GONE and your power is GONE...so you re-gear..to get that power back...idk what would happen if u went with 5:29's with like...31's or somethin the same...i've always wondered too...lol

 

I understand that its for performance. But with 4low, axle gearing is kinda a moot point in my opinion, especially with dual cases. So if its only to get my freeway speed up, and I have to drag the clutch and rev a lil higher, Ill trade that for knowing im not gonna spin a dif.

 

there are some misconceptions regarding lower gears. if you do not have dual cases and daily drive your rig with larger than stock tires, you will most likely want to re-gear.

as to the gears being weaker...
http://www.gearinstalls.com/410suck.htm

 

ALL gears have 3 teeth in contact at any given time. With lower gears (higher number) the setup is more critical to ensure this.

Your numbers are from non-Toyota gear sets ... here's the actual tooth counts for the Toyota 8":

Rato Ring teeth-pinion teeth
4.11 37-9
4.56 41-9
4.88 39-8
5.29 37-7
5.71 40-7

There are tons of people out there beating on 5.29 and 5.71 without problems.

 

I dont think thats correct. Could you post your sources. I always understood, that a higher ratio, meant smaller pinion gear, I have seen pinions out of a third, and there is a noticeable difference between a 3.90 and a 5.56, definitely. The 5.56 is much smaller, and when put on the ring gear, it didnt look like the same amount of teeth contacted to me. So in theory, smaller is weaker. Correct? Im not saying you cant beat on a 5.29, Im just saying that a 3.90 is noticably stronger. I could be wrong, but I dont think so.

 

to a point its a trade off, if you run big tires and a high ratio, lets use 4.10 since its common, your are putting much more strain on all of the components upstream of the diff (transfer case outputs, u-joints.) if you go with a lower ratio (5.29) you take the load off of those components and place it on the ring and pinion, yes a higher ratio gear set usually has a larger pinion, but i have friends that have broke a few 5.29 diffs and went with 4.10, guess what..... they broke those too, in this case the toy parts are just too small for the job

 

i know for a fact that 5.29's are 37-7, i just helped install them front and rear in a 86 SAS runner, with aussie and lockright.

tc's right, people beat the piss out of lower gears and few ever have problems

 

Ic. So even though your r&p are stronger, your putting undue stress on drivelines, and xfer case. Wouldnt that only matter on road. I got a top truck dvd from a couple years back, and all the guys in that ran a low r&p ratio, granted they trailered their vehicles there, but I remember them saying they went to a lower ratio for strength.

 

The highest gear ran in the 2007 TTC were 5.38's on a TJ with a 5.2L Dodge V8 running 42's on a High-pinion Dana 60/High-pinion Moser Dana 60 and the same gearing on a 77 Chevy running a 454, Dana 60/GM 14 with 49's.

Everyone else was running 2 1/2 ton Rockwells with 6.72's.

http://www.fourwheeler.com/toptruckc...ors/index.html

 

Did you read the gearinstalls.com link above? Did you see the pictures?

YES - there are fewer teeth, and the overall diameter is smaller

BUT - each tooth is bigger. How do you think a pinion breaks? Clean off? NO - the teeth strip off the "meat" of the pinion. Bigger teeth = stronger pinion.

3 teeth is simple gear theory - I'm sure there are tons of references on The Google.

 

i want to add, that most of the failures that Ive seen the pinion is fine but the ring gets its teeth stripped off

 

5:29's are proven in our trucks, they rarely break from what ive seen, Its much better then replacing a clutch every 6 months among alot of other parts, not to mention getting all that performance and gas mileage back.

If I had money now the first thing id upgrade on my truck would be gearing, 4:10's and 33's is not a good combo for daily driving or offroad. I plan on doing gearing and tires all at the same time though, 5:29's and 35's seems like the way to go.

 

Just remember that if you are going to spend the money to re-gear do it once and do it right. If you think you may run bigger tires sometime (DON"T Forget to upgrade your brakes too) gear for that now. If you think you may run 35's go with 5.29's for example, but if you don't think you will ever go bigger than 33's get 4.88's. No sense in doing it twice because you changed your mind 6 months down the road and bought a bigger set of tires....

In the 3 Thirds I screwed up, the pinion was always fine, it was the ring gear that got fubarred.

And yes regearing will change how your truck drives on the road, it will never make a 22R feel like a v-8 but is can bring some pep back in the old beast. A DD with 33's and 4.88's or 35's with 5.29's will drive around a lot better than that same truck with 3.90's (or 4.10's) with 33's or 35's.