Would someone with a late 80's early 90's dually do me a favor and take a measurement from inside to inside of the inner duals and outside to outside of the outer duals please? Might swap out to a dually axle on my truck and want to know those dimensions before doing so.

 

FYI, that dimension is going to really depend on which tires you are running.

 

I understand that, maybe I should have been a little more specific. Folks that have a dually in that year range with STOCK OR NEAR STOCK WIDTH TIRES.

 

this is old but may help answer
Dually Swap? - Ford Truck Enthusiasts Forums

 

For everyone's info..
1994 F Superduty dually axle Sterling 10.25( I believe) with 215/85R16 tires, tires are roughly 8 1/4 inch wide.
Inner dual to Inner dual----54 7/8 inch
Outer dual to outer dual----91 1/2 inch
backing plate to backing plate----58 18 inch
Spring perch to spring perch--- roughly 45 inch
Disclaimer::::These measurements are taken just by eyeball down the side of the tires,

 

Rear axle in the '87-'97 F-Super Duty/ F-450 is a Dana 80.

 

OK so the guy lied to me.

 

Actually it could have a Sterling 10.25", a Dana 70-HD or a Dana 80

 

Oh wow. That sounds familiar now that you mention it. How did they get the weight rating from a sterling 10.25?

 

Tires are what limit the weight rating on axles. The more you have the higher the rating.

 

Yeah but an F-Super Duty with a sterling 10.25 would basically still be an F350 cab & chassis.Well, short of the hydroboost brakes.If they came with sterling 10.25's did those have the disc brakes? They must of retained the drums like the pickups? What did the D70 have? How sure about the sterling's being in some, are you 89 flatbed? The 8th gen I'm guessing got this mixed bag and by '92 all must of had the D80's by then, I'd guess?

 

100% sure. I believe they where an option up to '94 but I'm not positive on that part. After 99 I believe they went to the Sterling 10.5.

 

Check out the third post down in this thread
https://www.ford-trucks.com/forums/9...s-by-year.html

 

Oh ok. Well the "F-Super Duty" was Fords "F450" truck and there's no mention of the F-Super Duty/F450 in his list there. The truck is even excluded under his D80 section. It's a pretty beefy rear on the '87-'97 F-SD/F450's with massive disc brake calipers.




Of course for it's time. Nowadays it's like a pickup sized rear axle lol! Ford has turned it's trucks into near medium duty trucks these days,it's insane.



What are you planning on converting to a dually? I've converted my F250 to a dually using an F350 DRW pickup axle. If you have a pickup you just have to make sure to pull your rear from a f350 dually pickup and not a cab and chassis because it's much wider.Either the first or second gen will work but depending on your driveshaft you might need a conversion u-joint.If you have an E4OD truck and need the VSS make sure the rear isn't too early and without the tone ring (pre '88 or '89 or somewhere around there.)
2nd gen sterling's ('93-97) are more desirable but really unless your running massive tires,the first gens are just fine and last forever and a day too.I used a first gen sterling as that's the only way I could find 3.55 gearing in 10.25 drw pickup form and just used a conversion u-joint.





Here's the dually axle I put under her.Measured between the backing plates.



That applies to F250HD and F350 SRW (as they are the basic truck/same platform) to convert either to a dually.If the "dually rear" you find is not even close to that measurement then it came from a narrow f350 C&C dually truck and it's not going to work.

 

The term f-superduty does not represent the f-450 alone, it represent all Ford trucks 3/4 ton and up just like it does in today's trucks except these day it's just superduty.