Competition Ford 9" Rear end for Sled Pulling??

[jwilliams3]

I got in to a conversation at work over the New American Axles that are provided with our Cummins Diesels.

Anyhow, we got into discussing the famous DANA 80 hybrid and 70 axles and how they survived for a good amount of time while sled pulling unless you ran into bad luck or a bad-ss sled.



Anyhow, both of the others in the conversation swore up and down you could build a Ford 9" rear end stronger then the DANA 80 hybrid axle ever could be!



I didnt think an axle for a half ton pickup could be built so strong?



Any info appreciated!



--Justin

 

[HVAC]

Curry (9" racing axle specialists) in SoCal said they couldn't help me. Too much weight for the power to hold up.

 

[fj40charles]

9" rear ends have a 3rd pinion bearing support. You can get 40 spline axles with nodular third member housing that might hold up. High pinion on the rear is not a good idea since your driving on the coast side of the ring gear.



For the extreme offroaders, Currie reverse rotation stuff is only good for up to 37 inch tires.



IMHO, a 14 bolt with thicker axle tube is probably better than a modified D80. 14 bolt rear tube is only 1/4" thick. Might want to go with some thicker DOM tubing.



charles

 

[BigBadDodge]

What is done to the Dana 80 to modify it or make it a hybrid ?

 

[fj40charles]

Dana 80 is supposed to have 10 lug bolts. Our rear axles have D80 centers with D70 outers to allow for 8 bolts.

 

[David Muench]

Originally posted by fj40charles

High pinion on the rear is not a good idea since your driving on the coast side of the ring gear.



For the extreme offroaders, Currie reverse rotation stuff is only good for up to 37 inch tires.

Just to expand on this - High pinion is really bad (for this application) for the 9" because you actually go down to 8. 8" gears and more importantly, loose the 3rd pinion bearing which makes the 9" so attractive.



I agree though, if I were looking to build a serious pulling axle I'd go with a GM 14 bolt and replace the tubes. Then you'd have an extremely durable housing and a 3rd pinion bearing. If you could find someone local to press in new tubes for you, you could even do it "cheap".

 

[Rob Thomas]

Have we (the 80 guys), been breakin' axles? Other than the spider's, what has broke? I mean this axle is overkill as it is, IMO. Why goto a bigger one? I do have a 14-bolt (10 1/2" ring) GM axle layin' around my shop, but why do I NEED it?





Later, Rob

 

[StakeMan]

Originally posted by Rob Thomas

Have we (the 80 guys), been breakin' axles? Other than the spider's, what has broke? I mean this axle is overkill as it is, IMO. Why goto a bigger one? I do have a 14-bolt (10 1/2" ring) GM axle layin' around my shop, but why do I NEED it?





Later, Rob

There is a reason why you don't need a bigger axle Rob.

 

[Rob Thomas]

Originally posted by StakeMan

There is a reason why you don't need a bigger axle Rob.

Hey Stakebutt, are you lost? This isn't a transmission thread.



Later, Rob

 

[F8LDOSE]

Just getting a 14bolt together to put into my 95. Hopefully I solve the problem of breaking the pinion. As far as axles, dana 80's are 35 spline and 1. 5 diameter while 14 bolts are only 30 spline and my Moser axles are 1. 5 nontapered in diameter. The only bad thing is nobody makes a 35spline locker for the 14bolt. Moser axles come with a 10year warrenty on the 35 splines and no warrenty on the 30 splines. As far as axle tube bracing, I'm copying some bracing techniques that I've seen in drag cars with 12bolts. The only real advantage I see with the 14 bolt is the pinion bearing support, and the fact that their a dime a dozen. Time will tell, but hopefully it is worth it.

 

[fj40charles]

Another advantage of the 14 bolt is the cheap cost of the detroit locker. Are you sure you can't find a 35 spline detroit locker?



Downside is the limited selection of low gears. I believe 5. 13 is the lowest you can go.



Charles

 

[power grizz]

NINE INCH MAKES GOOD FENCEPOST!!!:-laf



the difference in them all is the 80 has a larger pinion diameter!!!

the nine inch can get very large axle shafts and any tube you want but you cant get any bigger than the tiny toothpick pinion shaft. 60 and 70 and 14 bolt run all the similar dia pinions and still can get any combo of axle shafts/tubes.

i ve twisted a 70 pinion and seen a 14 bolt break under a mild 454.



we should be fortunate dodge offered us the 80 to hold up under the mighty cummins.

with the torque i think everyone would get tired of changing rearend parts with a mildly bombed cummins!

 

[F8LDOSE]

I checked everywhere, called a bunch of people and nobody has a 35 spline detroit locker for a 10. 5" 14 bolt. They are cheap around $250 or so, because you use the stock case.

 

[HVAC]

Dynatrac

Dynatrac was going to build me a D60. They said they could use the same axles as I'm running in my D80. No sacrifice in strength there. The 200 pound drop in weight was attractive.

 

[Rob Thomas]

So nobodys gonna answer my above question? I'm waiting.....





Later, Rob

 

[Roger rodbolt]

Originally posted by Rob Thomas

So nobodys gonna answer my above question? I'm waiting.....





Later, Rob

Okay Rob... ..... I'll put in my $ . 015. The Dana 80 is tough and beefy, wouldn't trade mine for a dozen 14 bolt rears if I had to sled pull with them. I personally know of one axle break and that was sled pulling with 37" Swampers. Something is going to spin when the sled slows you down because a good Cummins engine doesn't pull down. If you tires don't you will find the weakest link. The standard spiders gears will take more torque then most any gasser can put on a 3. 54 rear but can be trashed by a very bombed CTD, heavy sled, and digging tires. JMHO but the folks that Justin was talking to (re: 9" Ford) probably have been reading custom rod, off road mags etc. , and don't have a clue how much stress is put on a 3. 54 ring and pinion with a 1500 ft lb motor slowing thru 7 mph 'cause a 40,000lb sled is running up on your bed . Actually I don't think a 9" Ford would run a hundred thousand miles hauling freight for a hotshot'r either. LC

 

[Rob Thomas]

Thats what I thought, just wondered if I missed a Dana 80 breakage thread somewhere. Thanks larry.







Later, Rob

 

[jstarnes]

question

Do the guys who sled pull use a locker of some sort (other than the stock power lock) It seems to me that this would solve your spider gear problems and if you like the power lock then just get a PL from a ford d80 (2000or up)(the ones that I have seen are different from all other PL)and if you want a stronger axel than a Dana80 than get a dana 135 from a f550 17500gvw (but from first hand when you load a f550 down to over 18000 its a BIG slow pig!)

 

[fj40charles]

I would think the sled pullers would use a spool. IMHO, no locker is stronger than a spool.



Charles

 

[J.R. Adkins]

Who makes a spool for the 80?