[BLUE90]

Looking for feedback from anyone with the following setup:

I have a '90 with a 302 and AOD with 33" tires and 3.55 gears.
I'm looking to change gears, and I'm trying to find out the RPM's in OD (3rd gear) at about 60-70 MPH, with 3.73 and 4.10 gears.

I'm only taching 1600 RPM's @ 65mph, and have to drive around with the pedal to the floor. It's so bad, I already overheated my coil from the excessive heat generated by keeping the RPM's up.
I'm spending $2k on this change (incl. an Auburn L/S) and not sure which change to make.
I don't know how most of you say 33's don't require lower gears.
How about some help!

 

[Justshootme84]

You need 4.10 gears with those 33" tires. You can find the RPM formula on most 4wd sites, but that ratio will get you back to near stock.

 

[93_bronco]

hey noob you really should use the search button. If you would have used the search button you would have found this.

you can thank beerman for this
GEARS

 

[jerry 1 a b]

Just go here!

http://www.intercotire.com/html/table.htm

 

[BLUE90]

Thanks for the charts and all, but all of these charts I've seen are assuming you have a man. trans. or a 4spd. auto. That's why I'm asking for actual RPM #'s from anyone who has my same setup,and has either 3.73's or 4.10's.

Example: 4 Whel Parts has a chart, but it is set up for a 1-1 man. trans. It says if you have OD subtract 15-30%. Well is it 15% or 30%? Thats a big difference.

Beerman, thats quite a chart you put togrther. My hats off to you!

 

[Blaze]

I keep telling everybody..."Call Randy's ring and pinion!" :banghead They'll have your specific aplication with rpm type of tranny yadda, yadda, blah, blah...oh phuck it! Can someone make us a gears forum???:goodfinge
Maybe we could put it right up under the "What sizes tires will fit my lift" one...:shrug

 

[Damager]

it's not an exact science since tire sizes vary .. some 35's aren't really 35's and some are ... just go to various suspension sites, look at the charts .. call Randy's R&P and draw a conclusion of your own :twak

 

[Guest]

Just go here!

http://www.intercotire.com/html/table.htm

i dont think that chart pertains to ours... it says close to stock w/27's and 3.55's...

 

[Andy351]

first off blue90, 3rd gear on your tranny is 1:1, 4th (overdrive) is .667:1
second, you can't get 3.73:1 gears in a bronco, unless you get after market gears.

those charts figure your rpms out in 3rd gear for autos, 4th gear for manual because it is 1:1. this offers a universal standard to measure by.

i have 33s and 3.55s but i have a c-6, so my rpms at 65 are about 2500.

 

[BLUE90]

My tranny has 1st, Drive, & Overdrive. So your'e saying my 2nd gear (drive) would be 1:1?

The 3.73's are aftermarket (Quality Gear). The next gear dowm that is listed for 8.8's is 4.10. I just don't want to spend that kind of money and be dissapointed either way (too high or too low) after it's too late. The best way is to know what others RPM's are at. Thanks for the info.

 

[Fireguy50]

GO GET THE GEAR CALCULATOR IN THE TECH SECTION!
http://fullsizebronco.com/forum/showthread.php?s=&threadid=7228

 

[Fireguy50]

My tranny has 1st, Drive, & Overdrive. So your'e saying my 2nd gear (drive) would be 1:1?

NO! If you have an AOD
1st = 2.400
2nd = 1.840
3rd = 1.000
4th = 0.667

3rd is you "drive"
4th is your "OD" or "overdrive"

 

[jerry 1 a b]

i dont think that chart pertains to ours... it says close to stock w/27's and 3.55's...

That is the standard. Dude! It's just math people! What's the big deal. So you're a half inch off... who cares?

Here's the calculators to if you don't trust me. I'm tellin you it's not as hard as you're making it.

http://www.intercotire.com/html/calculators.htm

You can convert metric to inches, true mph, everything. If you go to the gear ratios calculator, you can input your tire size and rpm to figure what gear you prefer. It's a piece of cake. And when you go in there, they have the ratios for every major transmission in use to today.

 

[Drilim]

I think what needs to be said...

If your only 33, and need to regear, this is your best chance at going bigger all around. If you spend 2k on gears and ls, And then decide to lift it for 35's....Screwed.

Do you plan on lifting it at all?

I didnt pay attention to your sig...But, Before regear...Consider a high volume intake. Either bought, or custom made..A nice dual exhaust set up. Cleaning the throttle body and intakes for best air handling...This is sure to regain 'some' lost power.

2k for gears that you may need to change again in 6 months if you put on 35's seem like a waste to me.