Need to know if you can change axle and hubs from 7 lug to 8 lug. Or should I just get adapter.

 

Is that a 7700 series truck? If so I suspect it cannot be converted as it's really just an F150 but you should find more info over here.. 1997 - 2003 F150 - Ford Truck Enthusiasts Forums

 

Ford made a 7 lug axle? Huh, TIL.

If you can find one, swap in a Sterling disc brake axle off of an E-series van, which I believe were 8 lug.

 

It's a 7 lug 3/4 ton. Considered a light duty

 

The new body style F-250s (which were renamed F-150 7700 in '98 or '99) had 7 lugs. (And contrary to popular opinion, those are true 3/4 ton trucks. What everyone WANTS to call a "real" 3/4 ton is the F-250HD, which is a heavy duty 3/4 ton, almost the equivalent of a 1 ton)

The E-Series used a Dana 60 rear axle with disks, not a Sterling. From what people say, the Dana is a pretty big step down from a Sterling.

Which 8 lug do you want? The 8 on 6.5" pattern everyone used up to '97 or the metric 8 lug pattern used by the '99 and up SuperDuties? Not that it affects my answer much. I don't know of any way to convert or adapt to either one, other than getting an axle that came that way. The E-350 (and E-250?) vans will have a Dana 60 with disk brakes and the old pattern. Up to '97 F-350 and F-250HD will have Sterling 10.25" full-floaters with drum brakes and the old pattern. Up to '96 F-250 will have Sterling 10.25" semi-floaters with drums and the old pattern. And '99 and newer F-250 and F-350 will have Sterling 10.5" with disks (I think) and the newer pattern.

And as Conanski said, your '97 F-250 is covered in the '97 - '03 F-150 forum rather than here, the '87 - '96 F-150 forum.

 

I actually own a 97 10th gen 7 lug f250 , so the 7 lug came before 98 .. And one questioned about aftermarket wheels in another thread about the 7 lug , pacer is the only company making aftermarket wheels for the 7 lug trucks , they are " hole shot " wheels and suit the truck well ..

 

Yokes, this thread has been dead for 5 years.

Just because I saw this - the axle used in vans is a Dana 60 ISU. Really interesting piece. Dana 60 center section, Dana 70 sized axle tubes, Sterling style hubs. The large tubes allow you to put 35 spline shafts in them without having to send the axle out to get machined. The casting of the center section is tucked up pretty high, which is an improvement for ground clearance over a traditional Dana 60 or Sterling rear. Plus you get the aftermarket gear and carrier selection of a Dana 60. The guy that I bought my '94 from put one of these in the rear after grenading a Sterling 10.25. Seems to withstand abuse just fine.

 

Damn near every D60 Ford has used since the 70s has had a spindle bore that can fit 35spl shafts.

Saying "Dana 70 sized tubes" is also meaningless because of the wide variety of tube configurations that the D70 has had in its nearly 70yr production run.

I assure you the E350 D60 that's sinking into my yard does not have tubes comparable to the D70 out of a Dodge motorhome that's also sinking into my yard though it does have larger tubes than the 70s D60 I have lying around.

The E350 D60 is probably the best OEM rear D60 you can get but considering how cheap and readily available larger full float 8-lug rear ends are that's not much of an endorsement.

Anyone who can break a 10.25 will break any D60 in short order. They are nowhere near comparable in strength and anyone who tells you otherwise is a moron.

 

3.5" tubes vs the typically smaller tubes on a Dana 60 rear axle from the period and prior.

The failure mode on nearly every Sterling and Dana 60 I've rebuilt is the pinion. Typically shearing off at the splines. On stock Dana 60 stuff with less axle shaft spline count, axle shaft failures are very common. The axle shafts that were in the ISU were 30 spline and pretty dinky in comparison to a stock Sterling 35 spline.

As far as brute strength goes for a standard 8 lug rear axle, hard to beat either a Dodge Dana 80, or the GM 14 Bolt but they seem to fetch the money they're worth. People will practically give away van axles and think nothing of it. Anyway, off track of this thread's intent.