Looking for a more "modern" F-250, I've come across a few '97 F-250's that are thge SAME body style as the '97 F150's. I've also run across more of the '97 F-250 HD with the OLDER, more "square" body style.

What kind of axles do the F150-ish '97 F250's have compared to the '97 HD's? I know the engine and tranny in the new-generation are different from the older-gen, but I wonder about the rear axle (is it full-floating? and GVWR capacity?

 

Here is the forum for your truck. It is the same thing as the 7700 F150

Your truck uses a semi floating 10.25

 

Thanks. I love the idea of a Dana 60 rear, but I don't seem to find any real complaints about the semi-floating axles. Just as durable? over-built? How can they rate them as high as 8400 GVWR if the axle wasn't up to it?

 

You found the forum for the '97 "older style" trucks. We call them OBS (old body style) trucks for ease of identification.

1997 was basically a mid-year model change from the Heavy Duty trucks to the Super Duty style still produced today. It can make for an aggravating time when trying to get parts.

The '97 F250 Super Duty came with the same 10.25 rear axle as the '97 Heavy Duty. The switch to the 10.5 Sterling was made in 1999, IIRC. Both axles are full floating. The '97 non-HDs came with the semi-floating axle.

YOu need the GWVR for which truck?

 

Well, my current old '66 has the Dana 60 rear and is rated at 7500# GVWR, so I guess I wouldn't need any capability more than that, but I've never worried about overloading it, and I have a few times. If the Sterling-equipped F-250 is rated at 7700# GVWR (from what I've seen), then I guess it'll fit my bill; I just wonder about that semi-floater vs the full floater. Are they pretty much indestructable within their load limit?

 

No semi-floating axle will be as strong as its full float sibling, because part of the weight of the vehicle is resting on the axle shaft in the semi-float axle. It is just not as strong as the full float axle where all of the weight is on the hubs.

Most people will never take their axles anywhere near their breaking point. Heavy offroading, stupid offroading, or hauling big loads are where a person might expect to see the difference between the two types of axles.

 

As you've figured out, in '97 both the F-250 and F-350 were available in a "heavy duty" configuration, the same as the 92-96 "OBS" (old body style), along with a "light duty" F-250 based on the Heritage F-150 body style.

The OBS style F250/F350 was the high capacity model with a full float Sterling (sometimes called Visteon) 10.25 rear axle with a GAWR of 6250# in SRW configuration, drum brakes, and a 8x6.5 bolt pattern. The front axle is a Dana 50 TTB in the F250 and a Dana 60 monobeam in the F350s. From the knuckles out is pretty much the same on the Dana 50 & Dana 60, while the Dana 50 center section has more in common with the Dana 44 than the Dana 60.

The Heritage F250 was a stop gap between the discontinuation of the OBS F250/F350 and the introduction of the Super Duty in 1998 (as a 1999 model year). *I'm pulling this from my unclear memory on the 10th gen trucks* I believe the Heritage F250 used the semi float Sterling 10.25, but it used a one-off 7 lug bolt pattern (I think it was 7x150mm). The front axle however is the same 8.8 IFS as the 97-03 F150 (with the odd 7 lug pattern) so the front axle weight rating is much lower on the Heritage F250 than OBS F250/F350 despite the same RAWR.

The difference between the full-float and semi-float Sterling axles is the way the weight is transferred from the wheel the axle. The full float, the weight is transferred wheel > hub > axle tube while the semi-float transfers it wheel > axle shaft > axle tube. This is based on the location of the wheel bearings. This can be easily distinguished by the look of the axle: (taken from another post)

Semi-float axle:


Full-float axle:


If you're looking at the OBS F250/F350s, you'll have a hard time finding a semi-float 10.25. As far as durability goes and the OBS compares to a Heritage truck, I honestly don't know how the semi and full float differ in strength. On paper the full float is obviously better but I don't know how that translates in real life. I do know most people insist the full float considering the low cost of acquiring a full float axle (they're a dime a dozen).

As far as motors go, the Heritage F250s were available with the new modular V8s, while the OBS F250/F350 used the same 351, 460, and Powerstroke that the '96 model year trucks had.

The Heritage F250 is an odd cross between the 10th gen F150, the outgoing 9th gen trucks, and the coming Super Duty trucks. Add to the confusion of a still available 9th gen based F250/F350, and it could be difficult to get the correct parts and a parts store.

As far as comparing the 10.25 to the Dana 60 rear, the 10.25 and 10.5 are stronger than the Dana 60 rear in both terms of weight capacity and torque rating.