School me on the F-Superduty

[SLittle]

My truck is an F350 crew cab dually from 1991.

Underneath all the sheet metal, what is different on the F Superduty.

I believe the F-SD had 10 lug wheels. Do they still use the Sterling rear? Brakes different?

I've seen some F-SD's for sale locally with rotted cabs. Would it be worthwhile to pick one up, strip it to the chassis, restore that chassis, and set a crew cab body on it?

 

[snicklas]

The F-Superduty is a 14,000 lb rated truck.

The way they rolled off the assembly line, upfitters and decades of PO’s things can be different, but from Ford:

2wd, with a Dana 80 disk brake rear axle, driveline brake bolted to the transmission (the transmission is actually the one used in a 4x4 application, but has the brake instead of a transfer case). They were ALL two wheel drive.

Rockwell carry-all solid front axle (I-beam design)

10 lug hubs/wheels

Regular cab

Cab and Chassis 36 inch rear frame width.

Either an IDI or 460. I’ve not seen one with a smaller engine.

Most I’ve seen are white, or a safety yellow color...

They ride like a log wagon..... with the heavy weight rating, the springs are stiff.

The gear ratio is tall. The lowest you could get was 4.88, but the 5.13 or higher was common. So they normally top out at 70ish.

A crew cab could be swapped on, but it will take some fab work as the frame is different between a regular cab and crew cab.

My recommendation is, if this isn’t being used to be a heavy hauler, service truck, tow truck,etc, is going to be your family vehicle.... you don’t want an F-Superduty suspension. An empty truck will beat you to death....

Don’t get me wrong, an F-Superduty is an excellent truck for what it was built to do. But at just an everyday pickup, not so much. I know people that hated to drive on everyday with decent load because it’s a hard ride. I wouldn’t want to drive one as my daily driver.....

 

[SLittle]

The F-Superduty is a 14,000 lb rated truck.

The way they rolled off the assembly line, upfitters and decades of PO’s things can be different, but from Ford:

2wd, with a Dana 80 disk brake rear axle, driveline brake bolted to the transmission (the transmission is actually the one used in a 4x4 application, but has the brake instead of a transfer case). They were ALL two wheel drive.

Rockwell carry-all solid front axle (I-beam design)

10 lug hubs/wheels

Regular cab

Cab and Chassis 36 inch rear frame width.

Either an IDI or 460. I’ve not seen one with a smaller engine.

Most I’ve seen are white, or a safety yellow color...

They ride like a log wagon..... with the heavy weight rating, the springs are stiff.

The gear ratio is tall. The lowest you could get was 4.88, but the 5.13 or higher was common. So they normally top out at 70ish.

A crew cab could be swapped on, but it will take some fab work as the frame is different between a regular cab and crew cab.

My recommendation is, if this isn’t being used to be a heavy hauler, service truck, tow truck,etc, is going to be your family vehicle.... you don’t want an F-Superduty suspension. An empty truck will beat you to death....

Don’t get me wrong, an F-Superduty is an excellent truck for what it was built to do. But at just an everyday pickup, not so much. I know people that hated to drive on everyday with decent load because it’s a hard ride. I wouldn’t want to drive one as my daily driver.....

All the HD parts make it sound like a great project for pulling my 5th wheel camper. But... once you get to the campsite you also use the tow rig to cruise around so perhaps it wouldn't be ideal.

 

[chillman88]

Yeah you're probably better off beefing up an F350. Upgrade to hydroboost brakes, put some air bags in the rear... You can gear a 350 lower if you need to but a 2wd F350 will ride much better empty than a F-SuperDuty!

 

[Garbage_Mechan]

I had a fleet of them at one time. Pretty simple and rugged. Largest problem was the parking brake unit. The bearings are oil lubricated in a separate compartment that holds maybe 4 Oz of oil. If the seals leak it is gone in a day.
The diesel ones are not legal in CA unless they are registered as a motor home or something non commercial.

 

[Slicknik]

They are good for parts swapping and upgrading a f350 or even a f250

10 lug axles
Hydro boost brake system
HD leaf springs

Unless your hauling heavy 90% of the time the ride quality is poor

Also I’m pretty sure the f super duty and f350 shares the same frame in 91

 

[Garbage_Mechan]

If one fell into my lap today (and I wasn’t in CA) I would put a F350 Dana 60 in the front, 1356 transfercase, and a F350 cab and chassis rear (hard to find). Would make a great dump truck, service truck or dedicated trailer puller. Wouldn’t plan on putting a pickup bed on it since the frame is narrower than a pickup.

 

[BlackNoma]

Do all the f-SD trucks have the hydroboost brakes?

 

[Shadetreemechanic]

Do all the f-SD trucks have the hydroboost brakes?

Only the diesels as far as I know.

 

[Garbage_Mechan]

My understanding is all of the F-SD’s had hydaboost. Mine were all diesel but it has been posted on this site the gasones were hydra boost.

 

[IDIBRONCO]

The gear ratio is tall. The lowest you could get was 4.88, but the 5.13 or higher was common. So they normally top out at 70ish.

This is backwards. The bigger the first number in the ratio, the lower the gear ratio is. 4.10:1 is lower than 3.55:1, for example. I also can't see why anybody would want a smaller engine than an IDI or a 460 in one anyway. They were made to work hard, thus the FSuperDuty name.

 

[dlw4x4]

My dad had a red 96 F450 SD 460 5-speed that had hydro boost brakes and A/C. It was all factory. Don't know the gear ratio rear axle it had, but it was low geared. He used it to pull a 5th wheel camper to the campground. I usually towed the camper for him, it was a powerhouse and rode rough empty. When he died we sold it to a guy who used it to hotshot with.

 

[jaluhn83]

Realize also that they are in the medium duty truck category (class 4) which has significant registration and insurance impacts. Could get around that by using a f350 cab and registering it under that vin, although there some legal grey area there and you’d also still technically be limited by the 350 gvw rating.

There’s a few 4x4 aftermarket conversions out there - mainly ex utility trucks from what I’ve seen. Custom d70 front axle and 205 t-case.

 

[IDIBRONCO]

and 205 t-case.

That would be SWEET to have!

 

[nelstomlinson]

10 lug axles

I was dead sure you were wrong about this, so I went home and counted. Sure enough, 10 lug not 8. I really thought the wheels interchanged with my one-tons, and I was really wrong.

I have a possibility of getting a 10 lug rear end out of a much newer F450, with a better gear ratio and much higher capacity. I wonder what kind of problems I would run into? Would everything fit? I had passed it by because I thought I had 8 lug wheels.