Rear Axle Ratio

Reply Subscribe

Thread Tools

Search this Thread

Oct 12, 2010 | 10:46 AM

thiggy

Thread Starter

New User

Joined: Apr 2006

Posts: 4

Likes: 0

Rear Axle Ratio

How do I determine what my axle ratio is? My vehicle is 2002 F-150 SuperCrew with 4.6 litre engine, 4 speed auto, two wheel drive? Thanks.

Addendum: I just went back out and looked again at the sticker on my door and this time found an axle code that I had previously missed. It is "H9" . Does that indicate that it has a 3.55 limited slip axle? And if it is a limited slip diff. could it account for a slight whine that I have heard for years at about 35 and 70 MPH?

Oct 12, 2010 | 11:54 PM

highteckredneck

Senior User

Joined: Jun 2009

Posts: 433

Likes: 0

From: dayton texas

here is fords axle chart-

Axle Decoder Chart

Code Ratio Capacity Maker Type

12 2.73 3800 FORD REG
17 3.25 3300 FORD REG
17 3.31 3800 FORD REG
18 3.08 3800 FORD REG
19 3.55 3800 FORD REG
25 4.10. 5300 FORD REG
29 3.55 5300 FORD REG
35 4.10. 6250 FORD REG
36 3.73 7400 DANA REG
39 3.55 6250 FORD REG
45 4.10. 7400 FORD REG
49 3.55 7400 FORD REG
65 4.10. 8250 FORD REG
69 3.55 8250 FORD REG
72 4.63 11000 DANA REG
73 5.13 11000 DANA REG
H5 4.10. 3800 FORD LIMITED SLIP
H7 3.31 3800 FORD LIMITED SLIP
H8 3.08 3800 FORD LIMITED SLIP
H9 3.55 3800 FORD LIMITED SLIP
B5 4.10. 5300 FORD LIMITED SLIP
B9 3.55 5300 FORD LIMITED SLIP
C5 4.10. 6250 FORD LIMITED SLIP
C9 3.55 6250 FORD LIMITED SLIP
D5 4.10. 7400 FORD LIMITED SLIP
F5 4.10. 8250 FORD LIMITED SLIP
W5 4.10 8250 FORD LIMITED SLIP

not sure about the whine, i have the same thing guess i never noticed it if it does but i do have 38" mudders lol

Oct 13, 2010 | 06:18 AM

t.duggan.photo

Freshman User

Joined: Sep 2010

Posts: 39

Likes: 0

Sorry if this is stealing your thread, but what good is a limited slip?

Oct 13, 2010 | 07:09 AM

highteckredneck

Senior User

Joined: Jun 2009

Posts: 433

Likes: 0

From: dayton texas

A limited slip differential has clutches that distribute power evenly to both wheels, limiting the amout of wheel spin.

An open differntial (non- limited slip) has fewer moving parts. It sends power the the wheel with the least resistance.

So you can see that in (4wd, or drag racing or etc.) its better to have limited slip so both tires will spin in the back or else you will just get the one wheel burnout.

Oct 14, 2010 | 03:04 PM

Bluegrass 7

Lead Driver

Joined: Sep 2006

Posts: 7,907

Likes: 143

The rear sing is a minor assembly fault in the rear that seems not to cause anything to get worse.
It was a big warrenty deal back in 2000 and later.
I have it in my 02 Screw but you get to the point you don't hear it much at 145,000 miles. It has never gotten any louder and there has never been an issue even trailer towing at the limit of gross combined weights of 12,000 lbs.
.
In mild climates, on hard roads etc. limited slip may never be an advantage, but other locations and uses do benifit.