axle - Diesel Forum

**strokerman11** · 11-04-2009, 01:51 PM

is there a difference in the rear axle housing on a 97 superduty and a 99 f450? i know the brakes are different and the the rotors and what have you but the housing itself and the spindles? they both have 4.88 gears im not possitive on the ring gear size but if you have any input please let me know thanks

**SmokeyWren** · 11-04-2009, 03:24 PM

The '97 F-SuperDuty and the '99 F-450, both with diesel engines, have Dana 80 rear axles with 11.25" ring gear and 11,000 pounds weight capacity. However, the gear ratio in the '99 F-450 is 4.88, while the gear ratio in the '97 F-SuperDuty was 4.63 standard or 5.13 optional.

And there was a huge difference in rear brakes, with the '97 having drums and the '99 with disks.

**strokerman11** · 11-04-2009, 09:51 PM

so would an axle swap be possible if i am just using the housing off the 97 and everything else from the 99?

**SmokeyWren** · 11-05-2009, 04:30 PM

I don't know. But it makes sense that the Dana 80 guts of the differential, axle shafts and bearings should all work, if you kept the brakes, hubs, axle tubes and differential housing from the one you plan to keep. In other words, the internal parts should swap right over, but the external parts would be problematic.

The hubs and wheels are very different. In addition to drum vs. disk brakes, the bolt circle is significantly different. The '99 has disk brakes and hubs/wheels with 8-on-225mm bolt circle. (225mm is about 8.85"). The '97 had drum brakes and hubs with 10-on-7.25" bolt circle.

You mentioned spindles. I don't think the Dana 80 rear axle has what I call spindles. They have long axle shafts that go from the diff to the hubs, and the hubs fit on the end of the shafts. Unless your definition of a spindle is the end of the axle shaft, where the wheel bearings and hubs go, regardless of the length of the axle?

I usually think of a spindle as the stubby axle shaft on an IRS vehicle, but the SuperDuty doesn't have anything close to IRS (independent rear suspension). Or the stubby axle used on the front axle on our 4x2 trucks with IFS. Or the stubby axle used on some trailers. For example, here's my understanding of a truck or trailer spindle :
8 Hole 7500# Straight Spindle Stub Axle Assembly - GEMPLER'S