Rear axle up grade
 

Finally got my 86 dual cab dually road registered today.
Just a tad modified, 93 F600 Cummins 5.9, RTO610 trans and just about everything else replaced or rebuilt.
Looking for options for a stronger/ higher rated rear axle than the 7900 lb 10.25 I currently have..
Built this as a tow machine and for updating the gross towing capacity need to keep our authorities happy.
Do any of the later axles have the same wheel stud pattern?.
Even changing wheels here can be fun with licensing.
See the different spring options for these but nothing on load capacity.
Been through Garry's site like a Terrier on a rat but not found what I am looking for.
Cheers Steve

They had a Dana 70 and a Dana 80 axle. The only place I can think of to find one of these would be under a large RV or one of those small shuttle buses.

Make sure your tires and brakes are up to the task. And a lot of those heavier rearends have disc brakes in the rear, and you can lose your parking brake. A lot of those were 2wd and had the parking brake mounted right behind the transmission.

Thanks for the info, does the Dana 80 have the same wheel stud pattern or will the hubs change over? Though the disc brake option maybe better anyway. Easy enough to fit a trans brake on the RTO610.
Will go see what I can scrounge on the load capacities of those axles.
Cheers Steve

I am not up on the different rearends too much. As you probably know around 1999 when the superduties came out they went to a metric bolt pattern. But a lot of those rearends have better capacity. I believe that's also when they came out with the 10.5 rearend, a very close relative of the 10.25 you have now.

Yes, I see the very late are using the Dana as the top axle, just know nothing about the bolt patterns.
Ford seem a little funny with their axles, some codes are way heavier than others with the same series of final unit and ratios. Hard to find just what the differences are.
Cheers Steve

I may not be a help, but the early to mid 90's 10.25 had the longer pinion, which is an upgrade to the 80's version. The later models also had the 3 spider gear housing. I believe if you have a 10.25, the different weight ratings were due to spring packages, not necessarily a beefier axle. The 10.5 diff is a larger ring, but with the same bolt pattern up to the super duties. The 10.25 is a pretty strong axle as well as the 10.5. I have seen more 10.25/10.5 axles in the rear of these fords versus the Dana series, but that's only MY experience.

There must be something with the axles apart from the ratios as I have seen axle charts with the same ratio but different ratings. They do change with ratios, crawler type ratios are usually the highest rating but there are exceptions amongst them.
As for spring packs have not found anything on load capacity, just part numbers.
Cheers Steve

Consider me newly informed then!

All in all,to answer your question, if it is 2wd, I would think the drw Dana 80 out of the older f superduty trucks should fulfill everything you need, tire and wheel pattern interchange, fairly cheap, and the mercy brake is on the output shaft of the transmission. If you are looking for different load capacities on them, I'm afraid of what you may find due to the extensive uses of them!

Not disagreeing with you at all, just going by Fords list of code numbers for their axles and the load rating assigned to them. Some even have 3 ratings for the same axle.
Already have the long spline pinion and flange installed.
Agree in that case it maybe the spring that goes with them along with limited centres.
I just need to have paperwork to prove to the licensing mob here that the axle can take it.
Just take a look at the towing charts for the 86 F350, 2500 Lb difference between auto and manual, all comes down to engine trans and final ratio. The chassis is obviously the same.
Thanks for the input
Steve

Going back to the original post and question...

First off, I don't know that it's possible to increase the tow- or load carrying RATING of a truck. That will be up to your local authorities to decide. But the general consensus (at least in the US, maybe different down under) is that local authorities are generally unwilling to go out on a limb to accept any higher rating than the manufacturer originally gave. Take a 1 ton truck with a 9,600 lb GVWR and a 20,000 lb GCWR, put a monster turbo diesel, a dump truck trans and rear axle and 2 ton springs in it, they still probably won't rate it for anything more than 9,600 lb GVWR and 20,000 GCWR. Is it more CAPABLE? Sure. But no one has to accept your argument that you've increased the RATING. (Heck, they might even say that since you modified it even the original rating is suspect, that's what seems to happen in Europe).

So ignoring the question of rating (since we can't answer that), what axle? If you are looking at 2-ton trucks for the engine and trans, you ought to be looking in a similar place for a comparable axle. And don't worry about the wrong bolt pattern, you also need to switch to the wheels that are rated for that too.

So an axle out of something like an F-Superduty (the pre-99 "F-450" version, not a '99 or later F-250 or F-350), or an RV or schoolbus (but not just an E-350 based one, not sure when they started making E-450s or what they called them at first). Or go with something out of a later E- or F-450 or F-550. None of this will be a direct bolt-in, but with what you've done already it's not really that hard.

It is the local authorities I have to deal with. Hard but not impossible to increase the load rating. Have to have an engineer sign of on any work done.
One way people here have got around this is to add another axle to the rear but that is not my preferred option.
What I am looking at is not going over the actual load on the truck as what I wish to tow is a 5th wheeler. Basically comes down to what the truck is capable of getting moving and maintaining movement without exceeding the driveline component ratings which brings me back to the rear axle and universals.
Thanks Steve

If you want stronger then a Ford 10.25 you will need a Dana 80. The Dana 70 isn't as good as the Ford 10.25/10.5 in my opinion.

I figure the 10.25 should do it as there are ones listed with higher capacity than the code 45 I have. Just need another code with the higher rating.
Believed they can be beefed up a little with a 3 pinion carrier.
Thanks for all the feed back.
Cheers Steve

If you want to switch carriers put a Detroit Truetrac in.