dual rears-f-250?

speedrdr · #1 (**permalink**) 05-14-2008, 11:24 PM

i know it's been asked and answered about a dual rear setup not working on a 250 because of the frame width difference not having suitable clearance for the duals, but got a question with a twist. could a 350 axle be put under the rear if a frame pad/mount was fabbed? i.e. the frame rails be modified to accept the narrower axle from a 350 without compromising the strength of the frame? the thought crossed my mind that i could box the frame in front of and behind where the wheels would go and cut that section loose and bring it in the 4 or so inches and put a flat bed on it. is that too much sugar for a dime and a waste of time?

speedrdr

starmilt · #2 (**permalink**) 05-15-2008, 08:59 AM

Much easier to find a dually rear fronm a pickup that came with a dually bed its a bolt in
the ones that are too narrow are the cab and chassis.

LilDuke · #3 (**permalink**) 05-15-2008, 06:53 PM

Isn't it only by 4 inches though?

speedrdr · #4 (**permalink**) 05-15-2008, 08:23 PM

i'm not sure about the 4 inches. thought the cab and chassis was the wide one and the dually was the narrow one. gotta get my tape and remeasure, it looks like. thanks. maybe this will be easier to swap than i thought.

speedrdr

Dave Sponaugle · #5 (**permalink**) 05-15-2008, 09:13 PM

Cab and chassis frame is 34" wide.
The axle under it is the same axle that is under a SRW F 250 or 350, but the spring perches are moved in 1.75" on each side to line up with the narrow frame rails.
Cab and chassis trucks also have 2.5" wide rear springs.

All trucks that left the factory with a pickup box installed have a 37.5" wide frame and use 3" wide springs.

F 350 dually trucks have a 37.5" frame width, use 3" rear springs and have an axle that is 4" wider between the brake back plates.

dyoung14 · #6 (**permalink**) 05-16-2008, 10:34 PM

me and my dad changed a f350 dully axle under an f250 and it work fine till he blew the motor up

speedrdr · #7 (**permalink**) 05-17-2008, 01:08 PM

Quote:

Originally Posted by Dave Sponaugle

Cab and chassis frame is 34" wide.
The axle under it is the same axle that is under a SRW F 250 or 350, but the spring perches are moved in 1.75" on each side to line up with the narrow frame rails.
Cab and chassis trucks also have 2.5" wide rear springs.

All trucks that left the factory with a pickup box installed have a 37.5" wide frame and use 3" wide springs.

F 350 dually trucks have a 37.5" frame width, use 3" rear springs and have an axle that is 4" wider between the brake back plates.

thanks dave, knew that i was probably wrong on the widths. so looks like i need to cribbage me a dually axle.
speedrdr