Bronco Forum - Full Size Ford Bronco Forum banner

1 - 14 of 14 Posts

·
Registered
Joined
·
49 Posts
Discussion Starter #1
I just picked up a 94 bronco w/ a 5.8 and automatic. I am going to put a 6" lift with 35's on it. I plan on going to Michigans Silver lake sand dunes with it alot. What is a good gear ratio for the bigger tires to give it that quick out of the hole feeling in low range and still get ok fuel mileage on the highway?- I know there is no way around it, it gets bad fuel mileage stock but I don't want to running extreme rpm's down the highway with to low of a gear. Unfortunately the dunes are 7 hours away.

Let me know what you guys think-

Thanks
 

·
Retired
Joined
·
16,016 Posts
Its your choice but with an OD trans your choice is between 4.56:1 and 4.88:1 gears.. I would google search gear calculators and compare your stock 3.55:1 gears and tires 235/70/15's to the new gear ratio and 35's.. ;)
 

·
I scrape on both sides
Joined
·
3,035 Posts
I run 4.11 with my 35s on the e4od. No real complaints yet. Just make sure to weigh the beads properly before you put them in. Mine were off about 4 ounces in the rear tires
 

·
Registered
Joined
·
49 Posts
Discussion Starter #4
Its your choice but with an OD trans your choice is between 4.56:1 and 4.88:1 gears.. I would google search gear calculators and compare your stock 3.55:1 gears and tires 235/70/15's to the new gear ratio and 35's.. ;)
I'll have to find out for sure tomarrow what tranny is in it. I'm new to these year broncos, I thought the two tranny options were similar- or are they not?
 

·
Thanks 351w500
Joined
·
5,446 Posts
I'll have to find out for sure tomarrow what tranny is in it. I'm new to these year broncos, I thought the two tranny options were similar- or are they not?
Your Tranny is a E4OD Its the only auto tranny used from 90-96.

you should run 4.88's if your going to be in the sand, and there is no reason to run it in 4low.
 

·
Registered
Joined
·
2,312 Posts
4.88's would be ideal except for youll be screaming at highway speeds. lots of guys have said their efi's like the high rpms. but i have 4.56 and i run 2000 at about 60-65. keep in mind my speedo isnt accurate so it could be a little higher.
 

·
I scrape on both sides
Joined
·
3,035 Posts
4.88's would be ideal except for youll be screaming at highway speeds. lots of guys have said their efi's like the high rpms. but i have 4.56 and i run 2000 at about 60-65. keep in mind my speedo isnt accurate so it could be a little higher.
My 4.11s run 2000 at 65... Speedo could be a little off as well. But the super duty e4od may have a bit lower gearing than the Bronco/f150 e4od
 

·
Super Moderator
Joined
·
26,990 Posts
yo,

Gear Ratio Equations
Source: by Jer C (Godless, Beerman, SOLD) at FSB

"Remember that this is reference only and is based on equasitions from simple math.
Your tire size may be listed as 33/35/37, etc. but the actual measuremnet of the tire could differ once it is mounted on your rim.
Also this write is assuming you have an E4OD, or similar auto tranni.
These are figures that I came up with, to do your own just do:
Circumference of tire divided by the gear ratio you want.
Then compare you answer to the stock forward measurement of 25.5"s and then you will know if it fall over or under."




Gear Ratio Guide for Larger Tires; Scroll Down or Click, Another RPM/Gear Ratio/Tire chart if site reverts to main page; MIESK5 NOTE, Rough Country® removed this same chart from their site in FEB 2011 & company rep said it isn't there anymore.
Source: by Rough Country® via broncocity.com


Example:

The original tire size is 30" and the original gear ratio is 3.91. You plan on moving up to 38". Then the formula would be calculated as: (38*3.91)/30 giving you 4.95. Not all gear ratios are available so you have the choice between 4.88 and 5.13, 4.88 being the closest.

Choose a little bit lower gear ratios if you do a lot of off-road driving and a little bit higher if you do more long distance highway trips.

This chart is based on 65 MPH and a 1:1 gear ratio, on manual transmission (4th gear).

Please NOTE: If your vehicle is equipped with an automatic transmission the RPM wil be higher than shown on the chart, because some slippage will occur in the transmission and torque converter. With overdrive transmission, your RPM in overdrive will be 15 - 30% less than indicated, depending on the vehicle.
 

·
Retired
Joined
·
16,016 Posts
I'll have to find out for sure tomarrow what tranny is in it. I'm new to these year broncos, I thought the two tranny options were similar- or are they not?
For that year model you factory trans would be E4OD if automatic and M5OD if it is a 5 speed manual trans.;)
 

·
Registered
Joined
·
2,216 Posts
Agreed, 4.56s is what you want with 35's.
 

·
Retired
Joined
·
16,016 Posts
Thanks guys for all the input. I think I'm going to give the 4.56's a shot.

Aaron
Note if you looking at those chats they are 1:1 ratio and if your running an automatic you will be an overdrive trans which means you will run .70:1 ratio or close to.

I much rather use something like this over a chart..:thumbup


Not trying to knock Miesk's tools (the man gives out great info!!!) but to me this is a better tool than a chart. Just my opinion.;)
http://www.grimmjeeper.com/gears.html
 

·
Super Moderator
Joined
·
26,990 Posts
yo, NP..
the good, real-time experiences are in Pepe's LINK I posted

btw, the chart does show 4.56 for "Daily Driver, Best Overall Performance"
but "with an automatic transmission the RPM wil be higher than shown on the chart"

as compared to Pepe's;
"35"s with 4.10s = 26.8, 5% over stock roughly.
35" tire, 4.56 gears, 110.0" circ, forward 24.1", about 5% less
35" tire, 3.55 gears, 110.0" circ, forward 31", about 22% more than stock. That means that your motor is working (and your clutch or torque converter) quite a bit harder to move your truck. That's why it dogs so bad.

Prob w/going to other ratios is finding correct gear sets for the Dana 44

with the 4.10 gears because your rpm range would be lower.
"
 
1 - 14 of 14 Posts
Top