80's up rear axles/SRW DRW
 

I have an '86 F250 (4X4) with a Sterling 10.25 rear axle. I recently got a good deal on a '84 F350 with a dump set up (2WD) which is a dually but it appears to have the Dana rear axle. I am swapping the dump assembly to my 4X4 chassis. The Dana in the donor truck has 4:10 gears (I think). My Sterling truck has 3:73.

Ultimately, I would like to convert my Sterling rear end to be set up for duals. Question: what are my options to convert my Sterling to be setup for duals? Can I take the rear break drums off the Dana and put them on a Sterling (doesn't seem like that will work but I am asking)? If not, are there spacer kits available that convert a SRW Sterling to accept duals?

I have read things saying that the spring perches on the dual axles are different that SRW axles. I don't understand how that can be true if the frames are the same between the trucks. Why would the inside measurements between the spring perches be any different. If the DRW axles are actually wider than SRW axles, then I can understand the perches would be in a different spot if measured from the hub/break drum. Are the axles actually wider or are the drums just different on the SRW and DRW axles?

Secondly, I noticed the rear leaf springs are narrower on the 84 donor truck that what is on my Sterling (which are 3" wide springs). The stacks on the dump are bigger (more springs) though. Has anyone seen anything like this in the 80s early 90s?

Thanks for any information.

I don't think it's DRW vs. SRW that has different spring perch locations. But cab-and-chassis trucks (which are mostly if not all DRW) have a narrower frame than pickups (which are mostly SRW). So a DRW axle from a cab-and-chassis will have the springs closer together than the SRW axle from your pickup

Do you happen to know if the leaf springs are different on a cab/chassis set-up as far as the width of the springs themselves? Besides the frame being narrower, do you know if the DRW axles used on cab and chassis trucks actually wider (hub to hub) than a SRW axle from a regular truck or is just the drums that different to allow for the inside wheel clearance?

Yes, the c&c springs are narrower. I can't recall if the backing plate to backing plate distances are different between the c&c's vs the pickups or if it's just the perch locations. I can measure my trucks tonight if I get a chance. Personally I wouldn't use spacers if you are truly going to use it as a dump bed. Nor would I go from a Sterling to a Dana but that is purely preference. You already mentioned them but gear ratios would need considered also esp since you have the front axle to deal with in the 86.

What is the intended use of this truck with the dump bed addition? I know you are looking more for specifics but it might help formulate some ideas.

Yes, this does help. Now knowing this about the springs, I am beginning to think the dump bed truck is a cab and chassis. Assuming the frame is narrower that will require me to do some fabrication on the dump bed mounts/hinges if my truck's frame is wider...

Right, I can't just plop the Dana axle in since my truck is 4x4 even if I wanted to without swapping either my front axle to 4.10's or the Dana to 3.73. I would ultimately prefer to leave my sterling axle in it.

My 86 truck is not a cab and chassis if that is what you are asking. It was originally a style-side bed. If it is a pain to convert the existing axle to a dually set-up I would just leave it single wheel. I would prefer to convert it to duals if practical, if nothing else for the appearance.

For more context, the truck will just be for cutting firewood etc around my farm. It's not like I am trying to start a hauling business with it or anything. Honestly, I haven't even put tags on it the past 3 years.

The c&c frame should be something like 34" wide vs the 38 (I think) of your pickup.

Again, personal opinion but I'd stick with the srw. There are trade offs between srw and drw that for firewood and around the farm usage, I would favor the srw. Now if you are hauling goosenecks then a lot can be said for the drw stability. I would get the dump bed swapped over and then down the road think about either adding spacers (not my first choice but if you aren't trying to overdo a 3/4 you should be fine) or finding a drw f350 PICKUP you can straight swap the rear end out of.

You are correct. The dump frame measures 34" and mine measures 37.5" (a bit narrower 36.5" right above the axle as it dips inward there). While unfortunate, this should not make my dump swap too terrible as I can just weld a piece of 1.5" angle iron to the outside of the existing dump bed frame assembly. That will add 3 inches to the mounting width between both sides... Plus the hinges having to be moved at the rear of course.

I think I will just leave it SRW with the sterling for now. If I come across a DRW axle with the right gear ratio I can cross that bridge if I want. For now I might add a bigger set of leafs and helpers to what I have and call it a day for what I need.

Thanks. I'll keep you posted on the project if anyone cares

I looked up my truck's (the 4X4) axle code which is a C9. A Sterling 10.25 with 3.55 gears, not 3.73s as I wrongfully assumed. Should learn not to assume with these trucks after falsely assuming all frames were the same...

Now onto my next question, I know what my axle is rated at based on the GVRW stated on my tag etc., but why are some Sterling 10.25 axles such as the D5 (7400) or the F5 (8250) rated so much higher? Is the difference simply in the leaf spring options in the particular application?

That's a good question I hope someone chimes in on. Especially sticking with using the D5 vs F5 comparison. They are both drw, 4.10, limited slip, sterling 10.25 axles so why is one about 1000 more?
I could see leaf springs adding to some calculations but all the axles tables I've seen don't have any mention of any configuration outside the axle itself.

I did see the F5 was drw but didn't notice the D5 was. In addition to what makes those two different, what's the actual difference in the srw and drw Sterling axles? Bigger hubs/bearings? Wall thickness? Are the actual axle shafts bigger?

If it's still referred to as a "Sterling 10.25" I assume the pumpkin/gears/guts are the same...

While on the subject, where can I get my mitts on one these rear axles?!?!

69 Ford 8250 3.55 1991
Does a Ford mean it's a sterling?

I found an F5 in a jy a couple years ago but I'd venture a guess to say that moving trucks would be a good start for the heavier rear ends. RVs also.
Maybe when it's a bit warmer some measuring can be done but you could check out the auto stores online and see if the bearings have different measurements The drums are naturally different but I haven't paid close enough attention when doing brakes to commit anything else to memory.

Be interested in knowing the differences. I don't see how brake drums or even bearings could add several thousand pounds of weight rating. There has to be something different with the axle housing itself.

Ford can mean a Sterling, and it can also mean a 8.8 for that year. Yes they did put 8.8 Ford rearends in f250 pickups. These are f250 pickups, not f250HD pickups. So that might be some of the differences in numbers you are seeing. The f250 came with a lighter duty rear axle, it was semi-float like a car axle, but it did have 8 lug rims. The f250HD had the full float rear axle. This axle has the large black piece sticking out of the center of the rear wheel, and the axle does not support the weight like it does on a semi-float.

Speaking of all this, I certainly hope you are not moving that dump bed over to a regular f250 with a semi-float rear axle. I would have doubts that it would hold up very long with all that weight on it.

Have you eyeballed the f350 cab and chassis frame? The one I worked on was beefed up with added metal on the top and bottom of the frame. If your cab and chassis frame is like this, I would consider this before moving the bed over to the other truck.

I guess you are not worried about the front wheels matching? They did make cab and chassis trucks that were 4x4. The 4.10's will help better in the hauling department. The only problem with finding a frontend, they are all being gobbled up by people who buy these crewcab duallys and want to make them 4x4.

I'm fairly content to just leave it as is unless by some miracle the Dana axles drum assembly works on a sterling. I don't care about the front wheels matching.

It is not a semi float sterling. It's full float and the front axle is a Dana 50 TTB.

The chassis on the donor truck does have extra strips of steel on the top and bottom rails of the frame but they end at the back of the cab. The frame is shaped/molded mildly different as well. I also noticed the leaf springs measure about 4 inches shorter than my regular truck too so swapping those out and redoing all the shackles seems like more of a hassle than it'd be worth.

Really, all I need to do after seeing both trucks side by side is well/bolt heavy gauge angle on the outside of the dump bed frame that bolts to the frame. I can either weld flat steel to that and bolt it to the frame or drill down through the angle and into the top frame rail on the truck and bolt it that way.

Shouldn't be too bad (famous last words)...


​