almost_nick

what is my rear end axle? I have a 03 f150 4x4 and was wondering what axle i have b/c the tag is no longer on the axle

torkum

What letters is the axle code on the driver door? Probably a 3:55LS or 3:75LS

Found a copy of the codes:

Axle Codes

non-limited slip

X27 – 3:31
X19 – 3:55
X26 – 3:73
X25 – 4:10

limited slip

H9 – 3:55
B6 – 3:73
B5 – 4:10

almost_nick

thank you, but I want to know who makes the axle?? I have 3.55 and was wondering if they were dana's

almost_nick

anyone??

chad085

to my knowledge there are 2 axles used in the f150 lineup for 97-03, the 8.8 ford, which i think is basically a wider, 31 spline version of the axle used in mustangs, explorers and rangers. And also the 9.75 rearend, not sure the manufacturer. Sterling??? i know sterling makes the 10.25 that goes under the '250's.

From what i've seen the 8.8 went in most 2wd trucks, while the 9.75 is seen under more 4wd's, especially 5.4 trucks, and most screw's.

I think the 2 axles have a different number of bolts on the diff cover, i'll have to peek at my 9.75 and get back with ya.

almost_nick

thanks that would be great

theville89

i have a 2000 5.4 2wd with the 9.75 3.55 gears and limited slip. and i think the number of bolts on the 9.75 are 12 but im not 100% sure.

KevinT

I also need help.

I have a 9.75 axle and I want to verify that it has 3.55 gears.

My tag has:
V918 B
55975 2003

This site does not have the year that I need.
http://www.fordification.com/rearends-ford15.htm

Can someone please tell me what I have?

Thanks,
Kevin

driver444

All three of those axles are Ford (I think it's Sterling too) axles, not Dana. Ford uses Dana front axles in the superduty's.

The 8.8 has 10 cover bolts.
The 9.75 has 12.
The 10.25 also has 12, and is physically much larger than the 9.75. You can tell by looking if you have one of them.

The 10.25 was available on some F150's and light-duty F250"s, and was the standard axle on F250's and 350's untill 1999, when they went to the 10.5.

To verify your gear ratio, you can do the following.
1. jack up the rear of the truck and put it in neutral.
2. make a corresponding mark on your tire and on the ground.
3. have a friend rotate the tire EXACTLY 1 revolution, while you count how many times the drive shaft goes around.

If it goes around just over 4 times, you have 4.10's. If it's just under 4 times, you have 3.73's. And if it's about 3-1/2 times, you have 3.55's.

Kevin, I believe the "55" in "55975" signifies a 3.55 ratio 9.75" axle.

KevinT

driver444,

Thanks. The 8.8 with drum brakes went bad so I bought a 9.75 with disc brakes and the gears were suppose to be 3.55, but when a friend drove it out of my garage, it was in 4wd and one of the back tires was chirping while he was turning.

The guy that I bought the axle from knows a lot about Fords and he told me that it was an open 3.55 but I wanted to verify after hearing the tires chirp and watching it jump. (The inner-back tire of the turn was chirping)

I thought about jacking it up and spinning the tires as you described but I just scrubbed my garage floor and detailed the truck and I am too lazy to jack it up again

The differential did not have clutches or the S-Spring so I assume that it's not a limited slip BUT after putting one tire on and letting the jack down on that side, I attempted to turn the tire on the other side but was unable to turn it. If the differential is open, I assume that I should be able to spin one tire while one is on the floor? I don't think it's a posi but that would explain the chirping while turning. I noticed the ring gear and 4 small gears that rotated when I had the cover off. There wasn't anything fancy behind the cover.

Thanks,
Kevin