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Best gear ratio for 37 inch tires?

23firefly

Full Member
Joined
May 31, 2004
Messages
340
What gear ratio do you guys think works best for 37 inch tires?
I'd ideally like to be able to Hwy. drive my bronco to the trails, and still be able to wheel.
What do you think?
If it makes any difference, I'll have a Det. locker on the back also.
 

matt77

Jr. Member
Joined
Mar 2, 2004
Messages
80
Loc.
Southaven, Ms
I have a 2001 SUPERDUTY with 37x12.50 17" with 4.11 gears. The 4.11 gears brought it back to a little better than stock.The bronco iI have has 38.5x14.50 15" with 4.11 I haven't drove but a few miles ,but it drove fine in that short distance.I plan on going lower with either 4.56 or 4.88.
 
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23firefly

Full Member
Joined
May 31, 2004
Messages
340
Kind of seems like it comes down to 4:56 or 4:88

I have a NP435 so I'm less worried about my crawliblity. Not really sure I really want my bronco going 70 MPH but would be nice to cruise the HWy with out winding up the motor.
 

trailpsycho

Bronco Guru
Joined
Dec 11, 2003
Messages
4,856
THere are a couple of charts floating around that give the optimal gear ratios for tire sizes. I would think that you would want at least 4.56 gears, if not taller. Depending on your suspension, it may not have very good highway manners; let us know what you decide and how it turns out/handles on the highway. Good luck.

Here is a prior thread where this was discussed, I believe you can find a chart here too. http://www.classicbroncos.com/forums/showthread.php?t=41741&highlight=gear+ratio+chart
 

Brewbro21

Sr. Member
Joined
Jul 4, 2004
Messages
919
Miley that is a very cool link. You should put that in the tech section. You have made all our lives easier, now we don't have to do the math anymore, where were you about two months ago when I was trying to decide which tranny to go with? I had gear formulas everywhere.

Thanks again Miley very cool. :cool:
 

wildbill

Old Bronco Guy
Joined
Jun 29, 2001
Messages
6,885
;D ;D ;D I would think 4:88 would be a good choice for a tire that big Good luck. :p :p :p Bill %) :p :cool:
 

sicaz66

Bronco Guru
Joined
Aug 14, 2001
Messages
1,951
Loc.
san diego
i have 4.56`s with my 37" mtr`s. i would have went with 4.88`s but with an atlas and 500hp on tap i think i`ll have plenty of power to turn them. ;D
 
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23firefly

Full Member
Joined
May 31, 2004
Messages
340
Hey Sicaz66..........Do you have any pic's of your rig? I 'm going full length axels also, and would like to see how yours came out.
 

Neverupright

New Member
Joined
Aug 5, 2004
Messages
45
Loc.
Arlington, WA
I've run 4.10, 5.38, 4.56, and 4.88 all with my 36's. Like the 4.88 best. More torque but doesn't sacrifice the highway speeds. ( yeh, right like I'm brave enough to drive it on the highway! ;D )
 

Case

Sr. Member
Joined
Dec 7, 2003
Messages
855
miley that is a cool site. something to play around with and like has been said alot eaiser than using a calculator.
 
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