Spring question

[Matrix37495]

I just got a 2wd F350 CCLB with a 460 and was surprised to find it only has a 8700# gvwr. I don't imagine the frame is any different, but is the front suspension the same and if it had an IDI?

I fully intend to tow heavy with this truck and would like to get it to a 10,000#gvwr (though i know the VIN will still list it as 8700#). So do i need to change the front springs? Or can i just add overloads to the rear?









Mods: I put this here cause this is where i see most of the knowledge base. If it's necessary to move it I understand.

 

[PwrSmoke]

What's the year. I have a bunch of Data Books from the '80 & '90s and can look up frame specs and speing specs, as well as GAWR.

Edit: Whoops, just saw it's an '85.... stand by!

 

[Matrix37495]

Heres the door plaque if it helps...

You must be registered for see images attach

 

[PwrSmoke]

OK, here's the skinny from the '85 Data Book

1985 F350 CCLB, 4x2, SRW

Std. GVW was 8,700, payload 3985 lbs., with the following equipment:

Frame: Single Channel, 36,000 psi, Section Modulus 4.94-in3

Rear Springs: 5869# @ ground (no overloads)

Front Axle GAWR: 3215# or 4200#

Rear Axle GAWR: 5869#

Opt. GVW was 9,700, payload 4450# with the following equipment:

Frame: Single Channel, 36,000 psi, Section Modulus 4.94-in3

Rear Springs: 7311# @ Ground (including overloads)
Rear Overload Spring Rate: 710# @ pad (Note: The std and optional GVW truck use the same main springs (328/594#/in two stage springs) but the 9200 GVW has the overload springs. The overload rate is 575#/in. single stage, single leaf)

Front Axle GAWR: 3215# or 4200#

Rear Axel GAWR: 6084#


Note: Factory shocks for the diesel are bigger (1.38" vs 1") and the diesel front springs are heavier. The 460 is 278#/in,. std front GAWR or 384#/in. for max GAWR. the 6.9L diesel is 384#/in. at std GAWR and 399#/in. for max GAWR.

Note: If your truck is a really early '85, it will have a Dana 61 axle. If later, it's a Sterling full floater. Both axle are rated for the same 6250# load. Late breaking new: saw you post and the book says that truck built before 2/85 still have the Dana 61 axle. Presumably you can tell the difference. Doesn't really matter much in the long run.

Looks to me you can get up to 9200# GVW by going to the overload rear. It doesn't look like you needed the HD front springs to attain a 9200 GVW

 

[Devon Harley]

Mmm why not just tow with your idi?

 

[Matrix37495]

OK, here's the skinny from the '85 Data Book

1985 F350 CCLB, 4x2, SRW

Std. GVW was 8,700, payload 3985 lbs., with the following equipment:

Frame: Single Channel, 36,000 psi, Section Modulus 4.94-in3

Rear Springs: 5869# @ ground (no overloads)

Front Axle GAWR: 3215# or 4200#

Rear Axle GAWR: 5869#

Opt. GVW was 9,700, payload 4450# with the following equipment:

Frame: Single Channel, 36,000 psi, Section Modulus 4.94-in3

Rear Springs: 7311# @ Ground (including overloads)
Rear Overload Spring Rate: 710# @ pad (Note: The std and optional GVW truck use the same main springs (328/594#/in two stage springs) but the 9200 GVW has the overload springs. The overload rate is 575#/in. single stage, single leaf)

Front Axle GAWR: 3215# or 4200#

Rear Axel GAWR: 6084#


Note: Factory shocks for the diesel are bigger (1.38" vs 1") and the diesel front springs are heavier. The 460 is 278#/in,. std front GAWR or 384#/in. for max GAWR. the 6.9L diesel is 384#/in. at std GAWR and 399#/in. for max GAWR.

Note: If your truck is a really early '85, it will have a Dana 61 axle. If later, it's a Sterling full floater. Both axle are rated for the same 6250# load. Late breaking new: saw you post and the book says that truck built before 2/85 still have the Dana 61 axle. Presumably you can tell the difference. Doesn't really matter much in the long run.

Looks to me you can get up to 9200# GVW by going to the overload rear. It doesn't look like you needed the HD front springs to attain a 9200 GVW

Mine was built Jan 85 so it looks like a Dana axle. Whats the difference between D60 and D61?

I was thinking about using air overloads in the rear, but Seth wants to get rid of his 4 leaf overload pack so i may use that...

Thanks for the info

Mmm why not just tow with your idi?

My IDI doesn't hardly want to pull anything and it runs very hot just pulling itself. I got this truck for a future diesel swap, but i want to use it til i'm ready to swap.

 

[PwrSmoke]

They look similar but the internals are different. The Dana 61 was built to carry taller gears. Changing gear ratios in D61s can be tricky if you have one with an oddball offset... that's a long, boring story only **** gearheads enjoy.

 

[Devon Harley]

I see sorry she's sick and ya that will make a nice swap.

 

[Matrix37495]

I'm gonna keep the diesel for an offroad toy or something that doesn't need plates.

PwrSmoke, I had planned on swapping the rear for a dually axle. I'm guessing the D61 (as a whole) is interchangeable with the sterling 10¼"? How about a corporate 14 bolt?