Low gear questions - Hobbie? or anyone?

quickbiker · Post by **quickbiker** » Fri Feb 14, 2003 5:21 pm

Hobbie, you say some of your buddies are running 4.56's? What brand is it? I just wonder cause I could only find that Sierra Gear is the ony one that has it listed, and I dont' even know if that is for sure.

And you're right about not being much difference between the 3.73 and 4.10's. I was out at lunch today with a buddy that just got a new rubicon, and He has 4.10's and his rpm's are not that much higher than mine. So I figure if I do all that work, I should put in at least 4.56's.

Maybe the 2nd gen has a stronger front diff than the 1'st gen. I know the rear diff is a bit stronger. The 2nd gen has 7.63 ring and the older ones have 7.5".

Post by **HenryJ** » Fri Feb 14, 2003 6:04 pm

I have used and am using (HenryJ & Vega ) Richmond gears

They seem to perform very well.

If you plan on staying with the 31" tires I'd say go no more than the 4.10's or sacrifice any highway mileage.

IMO, the 4.3L seems to like the low to mid RPM's better than it's predessor the 2.8L and 3.4L crate engine.

If you plan on tires in excess of 33" then I'd go to the 4.56's , but that will be a weak point since you will have to go to the special cross pin and that would be really pushing it for the 7.625 case (JMO)

4.10 with 31's should put you close to the factory 3.73 with 29's, which is the best all around ratio, IMO.

With a different engine like a built small block or 3.4L I'd say go low since they love the upper RPM's .

Richmond Gear PDF catalog

P.S. Hobie are you still running the 3.42's? That has to be pretty bad with the 31's?

quickbiker · Post by **quickbiker** » Fri Feb 14, 2003 6:14 pm

OK, that was my general feeling from what I've heard. I was just wondering if the 2nd gen can go a bit lower, but I think the front spline count is still 26 and the pinion is very small.

So, I guess the max safe limit that keeps it all dependable is no lower than 4.10's and no bigger than 33's.

Sounds like a veener.

Post by **HenryJ** » Fri Feb 14, 2003 6:17 pm

Yup, but remember as I said three times in the above post Just My Opinion

Brad · Post by **Brad** » Fri Feb 14, 2003 7:42 pm

Randy's Ring and Pinion has a great website. I called them and they can send you 4.10s with install kits for about 400 dollars, front and rear. The 4.56 rear is only made by GM and therefore is $381 just for the ring and pinion (ouch). I think 4.10s and 3.73 are pretty close. I would buy something that would make more torque instead, like headers or something.

www.ring-pinion.com

Brad

a2b · Post by **a2b** » Tue Feb 18, 2003 3:46 pm

hmm, dont know about what brand. i know i could get the gear swap for 800 bucks at a rear end shop here. i knew we had 28 splines in the rear. i thought it was the same up front.

FYI, i have never heard of any problems with 4.56's breaking on the trail. the drive shaft always goes first or the cv's. as it might have a weaker point than stock, i dont think it would be the weakest point in the front end and therefore it will be alright.

Warnoffroad · Post by **Warnoffroad** » Tue Feb 18, 2003 6:45 pm

Arent 4.56's a little much for 31's. Most of the people on Zr2.com use 4.56 with 35s. How much power do you need

quickbiker · Post by **quickbiker** » Tue Feb 18, 2003 7:17 pm

Yea, I think your right. 4.10's be good for now for 33's. I'll try with my 3.73's first for lack of play reserve.

Warnoffroad · Post by **Warnoffroad** » Wed Feb 19, 2003 12:53 pm

Yeah but just after I said that I realized that the black rock crawlers I want to get only have 4.5'' BS vs the 4'' I have now. So today I did some meas. and I can fit 33x10 BF ATs, Although im still thinking about getting the 32x11s beacuse of the power. Do you know how much it is to get 4.56s and to have them put in?

a2b · Post by **a2b** » Wed Feb 19, 2003 2:22 pm

it depends on where you go, anywhere from 800 to 1200 bucks to have new gears installed.

and the reason people are running 4.56 on 35's...(not that there are more than 5 people on zr2.com with 35's) is because thats the lowest gear you can put in the front.

if you go 33's IMO, 4.56 is the what the truck needs. 4.10's are just not effective enough

heck, 4.10's come in the FX4 and the Rubicon and they have 31's on them.

quickbiker · Post by **quickbiker** » Wed Feb 19, 2003 6:50 pm

The only manufacturer of 4.56's I can find is Sierra gear at http://www.differentials.com/catalog/24.pdf

I think 33's would be great. That would be 1 more inch of clearance, sweeeet. I am still wary of 4.56's though. There was a reason most manufacturers stopped producing them.