ohohsilverado

hey is anyone running 4.56 gears and does anyone think that it would be a bad idea to go to these. anyone have any idea what shift points and other related parts would be affected or need to be adjusted.

whitt1

I am,but I'm running a 4L80E with a 2.48:1 first gear.I think a 4.10 might be a better choice with a 4L60E with it's 3.06 first gear.The 4.56s are a little noisy on the highway too.

vanillagorilla

iTrader: (1)

It all depends on what size tire you're running, and whether or not you do a lot of highway driving. Also what kind of gears you are currently running.

I have a tire that's over 31" and I do VERY little highway driving, so 4.56's were good for me, but maybe not for others. Ideally I wanted a 4.30, but nobody makes them for our trucks. As for shift points....YES they will need to be adjusted. Plus your ABS light will go off, and your speedo/odometer will be wrong. If you don't have a tune or means of tuning then you need to find someone or something that does. I didn't notice a drop in gas mileage at, and my rpm's on the freeway at 75 are about 2700. I recommend them for anyone with the good fortune of having an ECSB 4.8 with 20's or bigger.

edt: My gears don't make any noise at all....highway or street! But that's probably because they're set-up properly.

whitt1

My 4.56 gears don't make any noise,my exhaust is a lot louder because of the extra revs.

Soquel

I've heard that high of a gear ratio will weaken our rear ends. somtheing to do with the size of the gears.

vanillagorilla

iTrader: (1)

Did you hear this from the same guy that sold Jack his beanstalk beans?

What do you mean size? The 4.56's are not any bigger than any other gearset that's used in a 8.6" rear-end. They physically will not fit. I know offroading types run 4.56's and bigger all the time, and with +35" tires. If anything its the bigger tires that put extra stress on the rear-end, not the "size" of the gears.

whitt1

Actually the 4.56 gears are marginally weaker because the pinion gear is smaller and the contact surface between ring and pinion is smaller.I've smashed everything in my rearend ,but never managed to break a ring and pinion gear 4.56 or other.

vanillagorilla

iTrader: (1)

This is true, contact area is different. I went with 4.11's in my car vs. 4.10's for this reason. But usually its the ring gear's teeth that will let go first. I think our stock axles/c-clips will go before a properly set-up aftermarket set of gears.

Soquel

Eat your beans http://www.4wheeloffroad.com/techarticles/3194/

sfj

here is another vote for the 410's your highway gas mileage with be affected depending upon the speed you usually travel but it is a fact of life that at 80 currently with the 346 i run like 2200 rpm and like they say at like 75 they run 2700 rpm i am still gonna get some i just want to warn you about the mileage and hope you enjoy whichever ones you get i know i am gonna


oh and BTW