gear ratio's

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

vph1074

New member
Joined
Apr 15, 2012
Messages
4
Reaction score
0
Location
Milton Freewater, or
for some reason the 83 bronco 4x4 xlt that i baught from a friend who only had it for 4 months has a 77 ford f-150 rean end and 4.10 gears and the front has 3.54 or at least thats what the tag says on the pumpkin now i have an 85 bronco with 3.50 gears front and back my question is would it be bad to leave the gears in the front alone and just swap the rea end with the 85 bronco so that in my 83 i would have 3.54 in the front and 3.50 in the rear? i have been trying to take the gears out of the front of the 85 with alot of headaches and not much success. please help me figure this out. desperate in oregon.

 

miesk5

96 Bronco 5.0
Staff member
Moderator
Joined
Oct 18, 2005
Messages
9,071
Reaction score
1,020
Location
Floating in the Pacific
yo vph1074,

WELCOME!

As BULLY BOB Advised... do the rev count test.

"Another way is to remove the differential cover or the 3rd member and count the number of teeth on the gears. Unfortunately, this can get messy. However, it does tell you without a doubt what ratio you may have

Gear Ratio (ring & pinion teeth count)

Source: by currieenterprises.com http://www.currieenterprises.com/cestore/calculators/ringGearCalc.htm

Enter the number of teeth on the Ring and Pinion gears and click the "Calculate" button to view your results.

Because,

I made a mistake 15 years ago by telling someone to use the Driver's side door label to ID their Rear Differential (axle, pumpkin type, etc.); turned out that a previous owner had swapped a Dana 60 in place of the stock 8.8

so... a run down; read about the gear ratio here in the Bronco Zone Forums @ http://broncozone.com/topic/20082-help-me-need-to-know-specs-88-bronco-xlt-58l-351w/

Another way is to remove the differential cover or the 3rd member and count the number of teeth on the gears. Unfortunately, this can get messy. One somewhat easy yet very reliable way is to jack up the wheels, disconnect the driveshaft, rotate one wheel, and count how many revolutions the pinion yoke/****** makes.

If you turn one tire & the other one either stays still while the pinion rotates, or the other one rotates backward while the pinion stays still, or something in between, then you've got an open diff or a very weak LSD (like a Trac-Lok with too many miles on it). In this case, you need to secure one wheel (perhaps by lowering the tire onto the ground), then you can figure your gear ratio by rotating the airborne tire TWO full rotations and counting the number of times the pinion rotates. 3.73 turns means 3.73 gears. If you only rotate the tire once, then 1.865 turns means 3.73 gears.

If you turn one tire & the other one turns the same number of turns in the same direction, then you've got a good LSD or locker. In this case, you can just rotate the tires ONE full rotation and figure your gear ratio by counting the number of times your pinion rotates. 3.73 turns means 3.73 gears.

by Obi-Wan at jedi.com

Ford built our Broncos & other 4x4 trucks & vans with a numerically lower front gear ratio in the front Dana 44 than the rear so that off-road steering is enhanced. A Bronco built with 3.55 rear ratio would have a 3.54 ration in the front Dana 44; or; 3.08 in the 8.8 & 3.07 in the Dana 44; or 4.11 in the 8.8 & 4.10 in the Dana 44, etc.

Following was in my MS WORD Notes and the source, Randy's Ring & Pinion has removed it from their current web site; The gear ratio in the front of a four wheel drive has to be different from the front so the front wheels will pull more. There have been many different ratio combinations used in four-wheel drive vehicles, but not so that the front will pull more. Gear manufactures use different ratios for many different reasons. Some of those reasons are: strength, gear life, noise (or lack of it), geometric constraints, or simply because of the tooling they have available. I have seen Ford use a 3.50 ratio in the rear with a 3.54 in the front, or a 4.11 in the rear with a 4.09 in the front. As long as the front and rear ratios are within 1%, the vehicle works just fine on the road, and can even be as different as 2% for off-road use with no side effects. point difference in ratio is equal to 1%. To find the percentage difference in ratios it is necessary to divide, not subtract. In order to find the difference, divide one ratio by the other and look at the numbers to the right of the decimal point to see how far they vary from 1.00. For example: 3.54 ÷ 3.50 = 1.01, or 1%, not 4% different. And likewise 4.11 ÷ 4.09 = 1.005, or only a 1/2% difference. These differences are about the same as a 1/3" variation in front to rear tire height, which probably happens more often than we realize. A difference in the ratio will damage the transfer case. Any extreme difference in front and rear ratios or front and rear tire height will put undue force on the drive train. However, any difference will put strain on all parts of the drivetrain. The forces generated from the difference have to travel through the axle assemblies and the driveshafts to get to the transfer case. These excessive forces can just as easily break a front u-joint or rear spider gear as well as parts in the transfer case.

Source: by miesk5 at Ford Bronco Zone Forums http://broncozone.com/topic/21803-new-member/page__gopid__113959#entry113959

So, if you need to drive it on roads over the spring & summer; make the swap, but do Not Engage transfer case/hubs for 4x4 driving.

To remove the Dana 44,

Removal in an 88; "...pull the DRIVER SIDE axle shaft straight out. It shouldn't be too hard to pull out, but beware that it is a tight fit trying to get the U-joint out of the knuckle area of the axle housing. The axle shaft will pull all the way out of the housing. Do not attempt to pull the passenger side axle shaft out in the same manner, as it is held into the third member with a C-clip..." Miesk5 Note, in the Dana 44 Parts Break-Out Diagram, Dana calls the C Clip a Snap Ring

READ More by Chris @ http://2bigbroncos.net//technical/front_dana44.html

read this by Steve

ALSO,

Jeff at the Bronco Graveyard has offered a 2% discount to members of The BroncoZone for on line orders. To get your discount, enter the discount code BZMEMBER. Also you must include your BroncoZone User Name with the order.

http://broncograveyard.com

GL!

 
OP
OP
V

vph1074

New member
Joined
Apr 15, 2012
Messages
4
Reaction score
0
Location
Milton Freewater, or
Thanks I was just having troubles getting the pumkin out until a friend of mine had the right tool and I got it out now that I know how to swap it out its not as bad as I thought and thanks for all the input hopefully I will have some pics of Reba I did not get any of her when I first got her and now some of the work is already done but once I get her done I will post the finished photos.

 

Members online

Forum statistics

Threads
22,522
Messages
135,994
Members
25,129
Latest member
Boone_23
Top