I was going to be putting 5.71 ring and pinion into my project vehicle in the future, I have heard that that anyting over 5.29 is too weak to use on trails.

I would like to know what everyone has to say

 

I say search.

 

Had a friend with cryo and heat treated Yukon 5.71s. Those things were down right hard to grenade. Ran for a long time with only lake water and mud for lubrication. Then he went with some plain jane genuine gear 5.71s and they naded about about a month of wheelin.

 

search it, guy named zuk he builds em, swears by them that they are just as strong

 

x2 zuk
Read his wright up on 5.29 vs. 5.71 he makes a hell of a argument about 5.71's and there holding up. The bottom line with zuk's article is that they are as strong as any gear setup if they are installed correctly.
gearinstalls.com

article from Zuk's web site


571 gears generate the same and possibly a little bit more output torque.





I've read on the Internet that 571 gears are weak....and that 410 is strong. After researching this, I found the exact opposite to be true. Making up a test jig to test this is beyond my financial means. But much information can be learned by measuring the tooth dimensions and comparing. I also have a local guy running ZUK installed PRECISION 571 gears. He runs 40" IROK's and is not afraid to romp on that 4.3 Vortec while going up those waterfalls and the gears are taking it. More on that in the next write-up.



410 ring.....41 teeth on a 7.89" diameter.



571 ring.....40 teeth on the same diameter(a little bigger tooth).




***ring gear thickness***

410 on the left...................571 on right


Length of 410 tooth 1.428"



571 length 1.394"



root of tooth.....410 is about .500"



571 is measured the same



Top of tooth....410 measures .098"



571 is .138"



--pinion tooth length--

410 is a long 2.630 about.



571 is a good 2.350" about.


When I re-write this it will go like this.....

1-show that the pinion is stronger than the ring

2-show that the 571 ring is same strength (or maybe a teensy bit stronger) as the thin 410 ring

3-that the 571 ratio is actually capable of having same or greater output torque as the 410 ring

4-none of the above is true with poor gear installs

 

Why do people say 5.71's are weak?

Because the ring gear is weak? Doesn't make sense - less teeth = bigger teeth = stronger

Because the pinion is so small? But 5.29's are OK, even though they both have 7 teeth on the pinion?

Here's the deal - the lower the ratio, the more critical the setup. 5.71's get a bad rap not because the gears are weak, but because they aren't setup properly.

As for the "benefits" of cryo ... search, I've written about the metallurgy of it before.

 

A lot of people in this area spin the pinion on gears 5.29 and larger. It does have to do with the size though i think a lot of it has to do with being installed at installations and setting hte correct amount of bearing preload and backlash. Personaly if i gear down i set backlash to be less than orriginal specs and increase the preload on the side bearings and the pinion. This ive heard helps avoid spinning out the pinion.

 

Thanx for the feed back, I will probably be having a well respected local guy, that only does offroad truck work, install them when the time comes so 5.71's it is.

 

Check out Zuk's site www.gearinstalls.com for a lot of tips

 

they say there weak because the r&p in diameter is smaller than the 529s plus you get more of a contact pattern with 529s tha 571s

 

Wrong.

The ring is EXACTLY the same diameter. The pinion is pretty much the same size, as they both have 7 teeth.

The contact pattern should be EXACTLY the same (and the same as 4.10 or any other ratio for that matter) if installed correctly. If you mean the contact area, it is MORE with 5.71 than higher ratios due to the longer teeth.