re-gearing

bronco410w

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Oct 7, 2008
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jersey
i have 35's on the bronco with a 6 inch lift... D44 and a 8.8 .... what would be a good gear to go with... i do pull a trailor when i run my car at the track... im not worryed about gas milage... but i'd like to do at least 70 mph with out screaming the rpm's

so any advice would be great!

 

Seabronc

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The optimum RPM range for cruise is 2000 - 3000 RPM. Here is a chart from Jeff's Bronco Graveyard for selecting the proper gear ratio. Since your cruise is higher than that used for the bottom part of the page, use the formula at the top.



Good luck,

:)>-

 
Joined
Sep 21, 2009
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I have a 91 bronc on 39.5 tsl's stock axles 8.8 with 3.55 and front dana ( ? ) with 3.54 i believe. It has wrked well in the mud in low for about four years but now i've broken the rear end. I'm looking to chang to a 4.56 to 5.13 yukon gear. My Question is this. I've heard that the pinion gear gets to small to go past 4.56 and it might break easier. But also that yukon gears are much stronger and less likely to break. Does any one have solid info on this? I've also see that yukon makes gears for the 8.8 up in the 6.0's. I would like a 4.88 or 5.13 is this going to break?

 

PlumKrazy

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Oct 27, 2009
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Groton Ct
What Trans do you have That will make a diffrence I had 36s with 4.88 and man I love the power it gives but I have an E40D(auto W/Overdrive) I keep my Bias plys around 60-65 mph at around 2000 rpm gives me a great 15 mpg

 

Mike Sheldon

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Aug 3, 2010
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6" lift is really more than the normal lifts which I have seen on this car.Is this car running properly bcoz this is very old car which can't handle lifts like this. I am not sure about the gears but Good Luck!!!

 

69bronc347

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Aug 29, 2010
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southern michigan
well this is a good question, it depends on your transmission, does it have over drive? if it does i would say 4.56's, if it does not i would say 4.10's to 4.30's. if have made the mistake of putting to much gear into a vehicle and it sucks. this way if you stay a little conservative and you reall need the grunt you can put it 4lo. i believe thisit the way to go. i was unable to find it, but there is a gear ratio and tire size calculator, where you can plug in your gear ratio and tires size and it will give you your rpm and speed, keep in mind this is for non overdrive trans usually

 

Bebop Man

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Dec 26, 2007
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Rapid City, SD
I have found the Gear Ratio calculator here works really well for computing with the various transmission, tire size, and differential variables. You can also plug in different road speeds to see what RPM you'd be running to give a better idea of street driving performance.

 

BigGreenBronco

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Sep 8, 2009
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North Florida
I have 4.56 gears with stock axles

And 35 inch tires with e4od trans and 302 it is alot better!! With these gears but im considering a comp cam or a 351 w because the stock 302 is just not great on torque

 

tiller83

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Jul 27, 2009
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baton rouge
I have an 83 bronco,c-6 trans,4:56 gears and 35 inch tires and my truck hates to go more than 45 mph...4:56 is a good match to 35-36 inch tires if they measure 35-36 inches.mine only measure @32"-33" which would require a 4:10-4:11 gear.most tires are smaller than the tire is labled so its best to measure the tires actual diameter and then choose a gear...also after a certain size you may need to replace the carier,usualy the best time to install a traction device.if you have an e4od I'd recomend getting the best match gears and avoid the variable sizes,if its the aod I'd go with a slightly lower gear(higher number) and if its 3-speed like mine I'd go with a slightly higher gear(lower number).I also put in some extra springs out of my old rear leaves(2) to take the squat out when I'm towing or full.

 
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