Axle Ratio for Towing Question
12-25-2012, 08:07 PM
#1
Senior Member
Thread Starter
Axle Ratio for Towing Question
I have a 2012 F150, 4x4, SCrew, 5.0 L with 3.55 axle. I wanted a 3.73 axle, but when I purchased the truck during employee pricing there was none around. I would like to know why my truck is rated at towing 7500 lb with my 3.55 axle ratio instead of 9100 lb with the 3.73 axle. I was told the engine, frame, suspension and everything else is the same except the rear axle ratio.
I know the 3.73 axle will increase the rpm by about 200 - 300, but can't under standby why that would make sure a big difference in the towing capacity.
Also does anyone know what it will cost to change my rear axle to a 3.73?
I purchased a Bullet 286QBS Travel Trailer with a dry weight of 5200 lb and a hitch weight of 585 lb. I will also have the truck full with my family and dog. I think I will be right at the upper limit of the capacity for this truck when I add about 800 lbs of camping equipment in the trailer.
I know the 3.73 axle will increase the rpm by about 200 - 300, but can't under standby why that would make sure a big difference in the towing capacity.
Also does anyone know what it will cost to change my rear axle to a 3.73?
I purchased a Bullet 286QBS Travel Trailer with a dry weight of 5200 lb and a hitch weight of 585 lb. I will also have the truck full with my family and dog. I think I will be right at the upper limit of the capacity for this truck when I add about 800 lbs of camping equipment in the trailer.
12-29-2012, 12:45 AM
#2
Senior Member
Your truck will have no problem pulling that trailer. The cost to change the gears to 3.73 will be expensive. Keep in mind you need to change the gears in both the front and rear because it's a 4x4. Goodluck, Kevin
01-01-2013, 09:26 PM
#3
Senior Member
I run about 1000 lbs under GCWR and 200 lbs under GVWR when I tow.
I have the 3.55 gears too. If a very slight gear change makes 1600 lbs difference, then I do not concern myself with running right at the upper limit of my numbers.
I have the 3.55 gears too. If a very slight gear change makes 1600 lbs difference, then I do not concern myself with running right at the upper limit of my numbers.
01-02-2013, 06:49 PM
#4
Compare the GVW's with the 3.55 and 3.73 rear. IIRR the 3.73 uses a bigger housing and gets you another 500# GVW, all on the rear axle.
Now on the EB, the trailer weight rating is the same between the 3.55 and 3.73 with the standard tow package. To get the 11.XXX# on the Max tow Ford went to a bigger radiator.
Yeah, while the 3.73's and standard tow package is a valid option combination most dealers order the Max tow since it requires the 3.73's.
Now on the EB, the trailer weight rating is the same between the 3.55 and 3.73 with the standard tow package. To get the 11.XXX# on the Max tow Ford went to a bigger radiator.
Yeah, while the 3.73's and standard tow package is a valid option combination most dealers order the Max tow since it requires the 3.73's.
01-02-2013, 07:21 PM
#5
Senior Member
2011 and up F150's use a Ford 10.5" rear end for 3.31 to 4.30 ratios.
Compare
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FOR10.5-331-37
$1119.83
OEM Ring & Pinion set for '11 & up Ford 10.5" in a 3.31 ratio with a 37 spline pinion.
Original Factory gear for '11 & up Ford 10.5" in a 3.31 ratio with a 37 spline pinion. OEM gears are recommend...
Call 1-866-631-0196
for Back-Order
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Products
FOR10.5-355-37
$1082.11
OEM Ring & Pinion set for '11 & up Ford 10.5" in a 3.55 ratio with a 37 spline pinion.
Original Factory gear for '11 & up Ford 10.5" in a 3.55 ratio with a 37 spline pinion. OEM gears are recommend...
Call 1-866-631-0196
for Back-Order
Compare
Products
FOR10.5-373-37
$1092.80
OEM Ring & Pinion set for '11 & up Ford 10.5" in a 3.73 ratio with a 37 spline pinion.
Original Factory gear for '11 & up Ford 10.5" in a 3.73 ratio with a 37 spline pinion. OEM gears are recommend...
Compare
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FOR10.5-430-37
$896.30
OEM Ring & Pinion set for '11 & up Ford 10.5" in a 4.30 ratio with a 37 spline pinion.
Original Factory gear for '11 & up Ford 10.5" in a 4.30 ratio with a 37 spline pinion. OEM gears are recommend...
Compare
Products
FOR10.5-331-37
$1119.83
OEM Ring & Pinion set for '11 & up Ford 10.5" in a 3.31 ratio with a 37 spline pinion.
Original Factory gear for '11 & up Ford 10.5" in a 3.31 ratio with a 37 spline pinion. OEM gears are recommend...
Call 1-866-631-0196
for Back-Order
Compare
Products
FOR10.5-355-37
$1082.11
OEM Ring & Pinion set for '11 & up Ford 10.5" in a 3.55 ratio with a 37 spline pinion.
Original Factory gear for '11 & up Ford 10.5" in a 3.55 ratio with a 37 spline pinion. OEM gears are recommend...
Call 1-866-631-0196
for Back-Order
Compare
Products
FOR10.5-373-37
$1092.80
OEM Ring & Pinion set for '11 & up Ford 10.5" in a 3.73 ratio with a 37 spline pinion.
Original Factory gear for '11 & up Ford 10.5" in a 3.73 ratio with a 37 spline pinion. OEM gears are recommend...
Compare
Products
FOR10.5-430-37
$896.30
OEM Ring & Pinion set for '11 & up Ford 10.5" in a 4.30 ratio with a 37 spline pinion.
Original Factory gear for '11 & up Ford 10.5" in a 4.30 ratio with a 37 spline pinion. OEM gears are recommend...
Last edited by Twisty; 01-02-2013 at 07:23 PM.
01-02-2013, 07:33 PM
#7
Canuck with a truck
2011 and up F150's use a Ford 10.5" rear end for 3.31 to 4.30 ratios.
Compare
Products
FOR10.5-331-37
$1119.83
OEM Ring & Pinion set for '11 & up Ford 10.5" in a 3.31 ratio with a 37 spline pinion.
Original Factory gear for '11 & up Ford 10.5" in a 3.31 ratio with a 37 spline pinion. OEM gears are recommend...
Call 1-866-631-0196
for Back-Order
Compare
Products
FOR10.5-355-37
$1082.11
OEM Ring & Pinion set for '11 & up Ford 10.5" in a 3.55 ratio with a 37 spline pinion.
Original Factory gear for '11 & up Ford 10.5" in a 3.55 ratio with a 37 spline pinion. OEM gears are recommend...
Call 1-866-631-0196
for Back-Order
Compare
Products
FOR10.5-373-37
$1092.80
OEM Ring & Pinion set for '11 & up Ford 10.5" in a 3.73 ratio with a 37 spline pinion.
Original Factory gear for '11 & up Ford 10.5" in a 3.73 ratio with a 37 spline pinion. OEM gears are recommend...
Compare
Products
FOR10.5-430-37
$896.30
OEM Ring & Pinion set for '11 & up Ford 10.5" in a 4.30 ratio with a 37 spline pinion.
Original Factory gear for '11 & up Ford 10.5" in a 4.30 ratio with a 37 spline pinion. OEM gears are recommend...
Compare
Products
FOR10.5-331-37
$1119.83
OEM Ring & Pinion set for '11 & up Ford 10.5" in a 3.31 ratio with a 37 spline pinion.
Original Factory gear for '11 & up Ford 10.5" in a 3.31 ratio with a 37 spline pinion. OEM gears are recommend...
Call 1-866-631-0196
for Back-Order
Compare
Products
FOR10.5-355-37
$1082.11
OEM Ring & Pinion set for '11 & up Ford 10.5" in a 3.55 ratio with a 37 spline pinion.
Original Factory gear for '11 & up Ford 10.5" in a 3.55 ratio with a 37 spline pinion. OEM gears are recommend...
Call 1-866-631-0196
for Back-Order
Compare
Products
FOR10.5-373-37
$1092.80
OEM Ring & Pinion set for '11 & up Ford 10.5" in a 3.73 ratio with a 37 spline pinion.
Original Factory gear for '11 & up Ford 10.5" in a 3.73 ratio with a 37 spline pinion. OEM gears are recommend...
Compare
Products
FOR10.5-430-37
$896.30
OEM Ring & Pinion set for '11 & up Ford 10.5" in a 4.30 ratio with a 37 spline pinion.
Original Factory gear for '11 & up Ford 10.5" in a 4.30 ratio with a 37 spline pinion. OEM gears are recommend...
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01-02-2013, 07:54 PM
#8
Senior Member
10.5" keeps showing up. It's a huge rear end for a 1/2 ton.
I'll keep looking unless someone posts different.
This is from Randy's Ring & Pinion
Ford 10.5", '11 & up.
2011 & Newer. This differential has a 37 spline pinion as opposed to the 31 spline pinion found in earlier model 10.5" differentials.
Ring Gear Diameter: 10.500
Cover Bolts: 12
Ring Gear Bolts: 12
Spline Count: 35
Dropout: False
Pinion Support: False
Carrier Breaks: none
Rear Suspension: Solid
Pinion Nut Size:
Compatible with Models:
E-250 3/4 Ton: 2011 - 2011 (Rear) E-350 1 Ton: 2011 - 2011 (Rear)
E-450: 2011 - 2011 (Rear) F-150 1/2 Ton: 2011 - 2012 (Rear)
F-150 1/2 Ton: 2011 - 2012 (Rear) F-250 Super Duty 3/4 Ton: 2011 - 2012 (Rear)
F-250 Super Duty 3/4 Ton: 2011 - 2012 (Rear) F-350 Super Duty 1 Ton: 2011 - 2012 (Rear)
F-350 Super Duty 1 Ton: 2011 - 2012 (Rear)
This is from Yukon Gear and Axle
http://www.yukongear.com/DiffDetails...1%2b%2526%2bup.
I am seeing 9.75" for 2 wheel drives.
I'll keep looking unless someone posts different.
This is from Randy's Ring & Pinion
Ford 10.5", '11 & up.
2011 & Newer. This differential has a 37 spline pinion as opposed to the 31 spline pinion found in earlier model 10.5" differentials.
Ring Gear Diameter: 10.500
Cover Bolts: 12
Ring Gear Bolts: 12
Spline Count: 35
Dropout: False
Pinion Support: False
Carrier Breaks: none
Rear Suspension: Solid
Pinion Nut Size:
Compatible with Models:
E-250 3/4 Ton: 2011 - 2011 (Rear) E-350 1 Ton: 2011 - 2011 (Rear)
E-450: 2011 - 2011 (Rear) F-150 1/2 Ton: 2011 - 2012 (Rear)
F-150 1/2 Ton: 2011 - 2012 (Rear) F-250 Super Duty 3/4 Ton: 2011 - 2012 (Rear)
F-250 Super Duty 3/4 Ton: 2011 - 2012 (Rear) F-350 Super Duty 1 Ton: 2011 - 2012 (Rear)
F-350 Super Duty 1 Ton: 2011 - 2012 (Rear)
This is from Yukon Gear and Axle
http://www.yukongear.com/DiffDetails...1%2b%2526%2bup.
I am seeing 9.75" for 2 wheel drives.
Last edited by Twisty; 01-02-2013 at 08:09 PM.
01-04-2013, 09:16 PM
#9
I know the 7 lug f150s used the 10.25 rear which is basically the same as the superduty 10.5 rear except the 10.5 is a full float rear. The gear sets for both the 10.25 and 10.5 are interchangeable.
01-05-2013, 07:51 AM
#10
