I'm having trouble with Iding the axle that is in my 1989 F Super Duty dump truck. Truck has a 7.3 diesel, zf5-42 5 speed, 19.5" rear duals, with 16" front tires. Rear end is 3rd member type, not the typical dana 80 found in these trucks. I had to actually bring the rear calipers, pads and rotors in to the auto parts store so they could find the correct parts as parts are not listed. Brake parts are from 1 ton Chevy dually.

 

I can't help you any with the identity of that axle, but I did notice how those u-bolts are not setting square with the axle. That is putting stress in places it shouldn't and is not safe. You might think about finding an axle that fits, or if you really like that one at least moving the spring perches. I don't want to see you wrapped around a tree cause your truck came apart!

 

Rockwell C 103. Most came with drum brakes. The disc brakes tells me it either came out of a P-series or a highly optioned truck. Standard gear ratios were 5.83, 6.17 etc.

 

Looks like a dana 135 from a 99-05 F550
8 on 225mm bolt pattern

Could also be a D110 from a 05-07 F550
10 on 225mm bolt pattern

But like stated above, could be from a P chassis

 

Thanks for the concern on the U bolts, I had to look at them again, but all is fine. For some reason the picture makes them look crooked.
Also thanks for the axle info. It is a Rockwell C103 after looking at other info. I was thinking a Dana from later F550s but didn't make sense. The Ford dealer couldn't help me much since Ford stop supporting these. From what they said it was a rare option.

 

Glad all is well. In that pic, they looked really out-of-whack.

 

My 89 f-super duty has a Dana 80 with disc brakes and 10 bolt wheels. Surely you can find one salvaged some where. I know the E350 with duals used the Dana 80 but with 8 lug bolts

 

I can assure you that that rear did not come in that truck. If by some crazy chance that it did, I've just learned something. It came in GM's(hence the 13 1/2" GM brakes). It's an 11,000lb rear...FYI.

 

Don't let anybody BS you. Not any rare option. Someone PUT that axle there and it was NOT ford.

Easiest way to tell is axle code on door jam sticker

 

What is the weight class on that truck, I have a 90 f-550 10lug with the c130, it's a bullet proof rear end why change it? The millitary uses the rockwell's in the duece and a half's, they make lockers and electric lockers for them, look for a bones yard that specializes in the old trucks, I know there out there but cant remember the name, you can buy wholesale. I would dump a Dana 80 in a minute for a rockwell.

 

the weight class of the truck is the f450 range of 15k lbs.the oem dana 80 has 11k lb capacity rating.

well you could make a couple decent arguments i suppose for changing it.

1.if the poster in #3 is correct about gear ratio options of 5.83 & 6.17 .......who needs that? lmao.the dana 80 options of 4.63 & 5.13 were more than enough (or bad enough,depending on how you look at it.)

2.the dana 80 was oem to the truck.

3.so you can have matching wheels/tires to the front.i was recently informed how pricey the 19.5 tires are.

not sure i would bother swapping it out or not.rear gear ratio,how much the truck is used and current tire condition depending i suppose.

id like to know what made him make such a statement.call him back up and ask him what info he see's that lead him to that conclusion?
and like Brad says,please do look at the door jam stickers axle code and post it for us if you don't mind.
dana 80's:
axle code 72 = 4.63
axle code 73 = 5.13

 

Here were most of the available C103 ratios. I personally have never seen a fast ratio C103. Maybe they were put in some of the later models, and I've replaced a boatload of these in class A motorhomes due to heat or cracked housings.

There should be a tag just above the pinion and a tag(or two) on the right rear axle housing as to the pertinents of the particular unit.

3.70, 4.10, 4.11, 4.33, 4.56...Fast Ratio

5.13, 5.29, 5.38, 5.83, 5.86, 6.14, 6.20, 6.80, 7.20...Standard Ratio

David 7.3, What does your door tag read under Axle?. Didn't realize that Ford had an F-550 in 1990. I thought that they were all F-Superduty.

Just some random vehicles that I've seen these...

1986 P-Chassis motorhome
1998 P-Chassis mini bus
1972 C-40 Cab Chassis
First production of the C3500HD (gas only)
Some UPS trucks

I''ve never seen one of these in any Ford(not say that they don't exist). An easy way to tell without getting under the truck is to look at the hub. If it has a dust cap it's a C103, if it has an axle flange, its something else. I'm sure that there are other slight variants such as maybe being an A63 but very unlikely.

I'm basing this info on experiences. I've been told that there were some in the F500/F600 back in the 50's/60's but I haven't seen those either.

These rears have been out of production for a while now and parts are very expensive and hard to find.

Very interesting discussion guys...

 

i think Davids post of the 90 F550 is a typo on the year.

 

i do too.i didn't even notice it.my mind simply read '99 when i read it this morning instead lol!

 

even if it was a typo and was supposed to say 99, it is still BS.

The F550 from 99-05 used a Dana 135