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4:10 gears.... need some info on them

Old Oct 21, 2010 | 09:53 AM
  #1  
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Default 4:10 gears.... need some info on them

Im reealy considering a set of these, but I need to know things like

- will my rpms be at 3k at 70mph instead of 2k?
- I have 28 in wheels,
- how much will my rpms go up by just regular cruisin?


Please help me out
 
Old Oct 21, 2010 | 10:06 AM
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I don't have time, but if you can find the OD ratio for your trans and the ratio for your T-case you can use this:

http://www.rocky-road.com/calculator.html

What's the reasoning for the 4.10's? You planning on lifting and putting bigger tires on?
 
Old Oct 21, 2010 | 10:20 AM
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Because all you're changing is the final drive ratio, you can use a simple ratio.

Example w/3.42 existing ring and pinion

4.10/3.42=1.2 or 120%

So if you are turning 2,500 rpm now you're gonna turn 3,000 after the swap.

EDIT - don't forget that the amount of energy in a moving body is expressed by 1/2mv^2 so it's worse than it sounds on a lot of your components to go from 2,500 to 3,000 rpm: it's not a linear relationship. Rev's kill engines.
 

Last edited by b1heqh54; Oct 21, 2010 at 10:23 AM.
Old Oct 21, 2010 | 10:28 AM
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That being said, if you're keeping your current tire size go to 3.73, if you plan to lift and go with bigger tires, hold off and do the 4.10's then.

my $0.02
 
Old Oct 21, 2010 | 10:33 AM
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Originally Posted by oktain
That being said, if you're keeping your current tire size go to 3.73, if you plan to lift and go with bigger tires, hold off and do the 4.10's then.

my $0.02
Agreed, if you really need the extra torque for something like towing (or the oversize rubber). If you don't then I'd just plain save my money.
 
Old Oct 21, 2010 | 11:03 AM
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I started out with 2.73 and didn't know it until I blew my rear Pinion, so I upgraded to 3.42s... and then spun the pumpkin on those, and now I've got 3.73 in my rear.

I went from turning 2,000 at 55ish (No Speedo) and now I'm turnin around 3,000. My husbands Burban cruises at like 500... I don't get it, it hardly ever gets past 3grand while mine shifts at 5grand lol. Its cause mines a beast lol.

Basically as the rest said, if you don't plan on getting bigger tires then don't change your gears. I have to upgrade to 4.11 to turn 35s without a lot of strain, and I've got a K5.

What are you currently running now?

 
Old Oct 21, 2010 | 11:40 AM
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I want the 4.10's for more pickup off the line. im doin about 2k at 70mph, and about 2.3-2.5k at 80mph.... will that get alot worse?
 
Old Oct 21, 2010 | 11:41 AM
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Yes, if you want more punch off the line get a 2800-3000 RPM stall, I know some guys running those on their fullsizes, one guy has an SAS with 3600 stall on his Silverado and still muds/offroads fine
 
Old Oct 21, 2010 | 11:42 AM
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Dont forget that your gas mileage might go down. At least mine did.
 
Old Oct 21, 2010 | 11:42 AM
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I need SPEEEDDD!!!!
 

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