Why Dana 60?

[nvrstuk]

LP- Yup, only LP 9" I've blown I was crawling up a dirt hill and blew the pinion support right out the front!

HP- I wasn't running the Mega9 but I was assured that the TrueHi9 would handle the torque but I grenaded one with a 6K shift into 2nd on asphalt. Not doing that anymore.

I wheel mine, despise driving it in the rain seriously, I’d rather ride a motorcycle with no windshield in the rain than drive my bronco. Working on fixing that, at least make it better, but got a fellow members project that I’m committed to getting complete first.

Wish I could find my short video of me cruising thru a downpour filming it with the tunes blaring and having a ton of fun w/o my doors!

I think your rain is usually a ton more of a rain than our rain!

 

[nvrstuk]

Not sure I ever directly compared the Hi9 to a D60. Just mentioned that I grenaded Hi 9's and they were built with some high quality parts. I think I mentioned that I was talked out of using D60's by several shops after giving them the specs of my build. At one time I was thinking of using a D60 HP for rear steer- even had the axle with knuckles but with the amount of DD I do I didn't think it was a smart choice and the agreement that the back side of D60 gears wouldn't stand up to the abuse.

 

[hossbronco]

Don’t forget that anyone in the rock crawling community is focused on ultimate strength and shock load features. For sustained high torque loads, you will have different results.

The Dana 60 hypoid pinion, when loaded in positive thrust will outperform the 9 inch (in sustained pulling) by about double. The 60 uses a HM803146 tapered roller (3.5 inch OD) for the inner pinion. The 9 inch uses a M88048 (2.688 inch OD) The 9 inch has an allowable dynamic load of 61.1 kN. The Dana 60 is good for 124 kN. That means that 60 can push twice as much load up the same hill.

I’m not saying the 60 is better for your application. And I’m not saying that the 9 inch is better. I’m saying that depending on the application, there’s advantages, and disadvantages. At the end of the day, the recipe that has worked for the most people, running 35-39 inch tires across the community is a 35 spline 60 up front, and a 30 spline 14 bolt out back.
Your mileage may vary…

I think reducing axle design to just a discussion on pinion roller bearings is misleading as there’s much more to differential design than just that. However, the GearWorks HP10 uses HM804846 bearings which have a 3.75” outer diameter and are quite a bit stronger than the HM803146 bearings. Again, that’s the rating of a single component and not the whole system.

There are plenty of hardcore rock crawlers, including Gordon Bailie, who love high pinion 9” axles because they’re not heavy on the throttle and love the added clearance. But I believe a fully built low pinion 9” rear end center section will hold its own against a Dana 60 rear, as will a fully built high pinion 9” front center section against a Dana 60 front. If this were not so, the 609 wouldn’t even exist.

Again I’m not trying to say one is better than the other as it comes down to preferences and trade offs, but I reject the notion that a Dana 60 center section can push twice the load of even a stock 9”, given similar gear ratios, etc.

 

[hossbronco]

LP- Yup, only LP 9" I've blown I was crawling up a dirt hill and blew the pinion support right out the front!

HP- I wasn't running the Mega9 but I was assured that the TrueHi9 would handle the torque but I grenaded one with a 6K shift into 2nd on asphalt. Not doing that anymore.


Wish I could find my short video of me cruising thru a downpour filming it with the tunes blaring and having a ton of fun w/o my doors!

I think your rain is usually a ton more of a rain than our rain!

Thanks. Some good information there. Was this a stock LP setup, or were you using a custom third member?

 

[nvrstuk]

Thanks. Some good information there. Was this a stock LP setup, or were you using a custom third member?

Stock. I hadn't gone nodular yet..I was still believing that a 9" was the strongest rear end on the market (that's what all the hot rodders were saying). Course I'd seen "King Kong Strong" Detroit lockers grenade for decades and I didn't believe that hype anymore but I wanted to believe! LOL

That was 20 yrs ago almost. That kept things together till the 31 spline axles twisted off (can't remember what caused that). Then I went TruHi9 as a "permanent solution". I was convinced that this setup was going to solve my problems. I was still running my ZF/203 combo as I'd built that with Gary's advice back in '99 as there wasn't any kits for that back then. I was thinking back then I needed to "soften" the shock loading caused from a manual so I installed the 4r70 and that's when I twisted the 35 spline ARB case right in half- POOF! Way later I put together my 914 as I called it, circa 2017. A Hi9 with RuffStuff's new housing with 14 bolt ends and RCV 35 spline axles and RCV FF ends. Thought it would last forever...
When it blew Steve convinced me the "lowly" 14 bolt would work and after shaving 1 3/8" off the bottom it had the same clearance as my fabbed housing 9" lol- after all those years of trying everything and a stockish 14 bolt was the ticket. Wish I'd known Steve back in '98 when I started building "stronger" rear ends.

 

[Yeller]

Loving this discussion!

In my opinion a 9” can have, preface on can with the right parts, survive higher ultimate torque loads. Even driving on the coast side a hi9 rear gets close. I agree with James that in stock form the 60 will out perform a 9” in just about every scenario, start adding Daytona pinion supports, 35 spline pinions with much larger bearings and things change rapidly. IMO any one street driving with more than 31” and more than 3.73 gears needs to have a Daytona pinion suport, the pinion bearing at the head has a short life without it. As for continuous load there is a reason you could get an f150 with a D60, because the 9” couldn’t keep up with the constant torque load on heavy use applications. in stock form, mostly the stock pinion bearings would cook, they are tiny.

As for which is stronger it’s like asking which cut of beef is better, it’s as much in the prep and personal preference as the cut, that prep is where the real money is and makes or breaks that cut. A steak with the right prep from a 20 year old wore out cow can be down right tender and tasty where as a ribeye from a prime steer can be terrible without the right prep.

As for brute strength, except for D44’s I personally have killed more D80’s than any other rear end, anything has its breaking point.

For brute strength and out of the box strength the lowly 14 bolt is still king for what most of us do, and in my opinion the benchmark that the high end 9”/10” axle builders are trying to match or beat, they are are building very similar parts, using the same bearings, ect. I’ve use them in front and rear applications very successfully. The advantage to the high end stuff is the housings are stronger and lighter by the time you get them both trussed for trophy truck use.

Racers love the 9” for is size, weight, strength and ease of service. There is something to be said that you can have spare in the pits, completely rebuild the axle in the pits in well under 30 minutes, been there done that, not happening with any integrated carrier housing.

Also consider top teams completely disassemble and inspect everything by the engine, transmission and tcase the night before any big race.

 

[hossbronco]

Keep talking and you may talk a GM product under the rear of my Ford. I always thought if a 9” can be built to withstand KOH for everyone out there, it can be good enough for me. The weight savings is nice, but I spend much more time in the rocks than the dunes, and quite a bit on the street. I’ve seen too many buckled driveshafts for my liking. A HP 9” will tuck that thing away, regardless of strength.

I also thought if, at the end of the day, a 9 inch just isn’t cutting it, a Dana 80, if even not quite as strong as a 14 bolt, would do just fine and wouldn’t be a GM product. That may be the case, but when I’m not sacrificing anything on my build, short of an all-out racing budget, why sacrifice on the backbone of my build? I may have to swallow my pride and install a lowly GM product. There’s a reason that’s what the rock bouncers are running.

 

[Yeller]

My big thing about the 14 bolt is its simplicity. Sets up like a 9”, just everything is on steroids. It also gets the pinion up, if I remember correctly, 1-1/2” from a 9”. If it helps don’t think of it as AAM (manufacturer) and their take on the Eaton axle from the 60’s lol.

I look at a 9” variants as a race axle and the 14b a wheelers/drivers axle, same with D60 fronts vs 609.

Not using race parts on your wheeler/driver makes it less expensive, leaving more money to go play. The ability to mostly have off the shelf parts is huge. Need a pinion or hub seal because you packed it with sand and is leaking in Escalante UT is a huge advantage. Not doing that with one off or low production race parts.

 

[1969]

If I ever grenade the Sterling 10.5, my Bronco will get a 14 bolt.

 

[Yeller]

If I ever grenade the Sterling 10.5, my Bronco will get a 14 bolt.

I’d be surprised if you really ever hurt the sterling. Strength of the locker has me curious. Rumors of breakage but not actually seen any. My only experience is playing with it in a parking lot in our work trucks, for some reason we spec it in our 2wd crew cab long bed f250’s. Most of the people that drive them have no idea what it is let alone it’s there or why/when to use it.

 

[1969]

I’d be surprised if you really ever hurt the sterling. Strength of the locker has me curious. Rumors of breakage but not actually seen any. My only experience is playing with it in a parking lot in our work trucks, for some reason we spec it in our 2wd crew cab long bed f250’s. Most of the people that drive them have no idea what it is let alone it’s there or why/when to use it.

I’m pretty gentle on my stuff, but I guess you never know. For $500 to get the factory selectable locker I’ll give it a shot and hopefully it doesn’t fail me on the rubicon but I’m not worried about it.

 

[nvrstuk]

Good stuff going on here!! Love learning.

I used to think I was "gentle" on my stuff too-no seriously, I did.
I never bounced when going over rocks or objects to eliminate shock loading, etc etc... but I found over the decades that I tend to play a little harder & longer than others. 6K while plowing thru headlight deep slush/ice with tires spinning at 45mph and me moving at about 10mph for just under two minutes at time. How many 1/4 mile dudes run WOT for almost two minutes? My buddies would do that for 5-10 sec. THAT kind of use. Hitting that steep sand dune 5X in a row at WOT instead of just once.

Guess it adds up.

 

[nvrstuk]

The picture I took of my 9" dropout sitting right next to my 14 bolt really convinced me. Especially the ARB size difference..Huge difference. I'll look for it-it would make anybody a believer!

 

[nvrstuk]

FOUND IT

Think a 9" is designed to handle the same loads, torque, etc as the beast in the pic next to it? Wish I'd kept the ring gear on it but it was mashed.

For a much clearer pic of this go to this page and link on my build thread from a few yrs back. https://classicbroncos.com/forums/t...5-wb-stretch-2-floor-lower-p-s.278607/page-19
Post #379

Looking at the center section for housing the spiders and locker.

Look at how much space ARB & others have to make strength a non-issue when the locker is in the 14bolt. Then look at the 9" center section and you can see there is just so little space to put some real meat in there!

The story that goes with this is back in February of 1987 when I bought my 1st ARB and put it in my Dana 44 (which Tim from ARB still believes was the 1st unit sold for a Bronco in the PNW) I digress lol

I remember asking ARB at that time how long it would be until they had one for a ford nine inch rear and they told me it would be 6 months. They told me the Ford 9inch was their largest market share and that was their biggest potential market share for selling their lockers.

Well I bought the first gen ARB production model back in 1996- or 97 for my 9".

It took them that long (almost 9 yrs) to finish the design and make it fairly reliable at that time.

9" wasn't supposed to be a truck rear end! Who knew we would be putting sticky compound 39" tires with 100% lockable axles, with gear doublers and 600ft lbs of torque climbing a vertical wall so ALL torque and the majority of the weight transfer might be transferred to just the rear axle and possibly only one tire. Talk about asking a lot of a diff that was designed in the '50's and designed for use in cars!!

 

[Yeller]

Crazy when you think that the 9” was discontinued by Ford in 1986. I think they are more common now than they were in 1986 lol

Dana’s axles for the most part are still in production with the same parts, let’s not dive into the variants of the 44, 30 and 35, let’s stay with 60’s and bigger.

 

[hossbronco]

FOUND IT

Think a 9" is designed to handle the same loads, torque, etc as the beast in the pic next to it? Wish I'd kept the ring gear on it but it was mashed.

For a much clearer pic of this go to this page and link on my build thread from a few yrs back. https://classicbroncos.com/forums/t...5-wb-stretch-2-floor-lower-p-s.278607/page-19
Post #379

Wow! The difference is comical! You have me leaning towards a 14 bolt rear now, and I’ve been dead-set on my 609. Still like the 609 front.

 

[hossbronco]

My big thing about the 14 bolt is its simplicity. Sets up like a 9”, just everything is on steroids. It also gets the pinion up, if I remember correctly, 1-1/2” from a 9”. If it helps don’t think of it as AAM (manufacturer) and their take on the Eaton axle from the 60’s lol.

I look at a 9” variants as a race axle and the 14b a wheelers/drivers axle, same with D60 fronts vs 609.

Not using race parts on your wheeler/driver makes it less expensive, leaving more money to go play. The ability to mostly have off the shelf parts is huge. Need a pinion or hub seal because you packed it with sand and is leaking in Escalante UT is a huge advantage. Not doing that with one off or low production race parts.

That’s compared to a low pinion 9” though. A HP 9” gets the driveshaft much higher.

Why do you suppose you’ve blown up so many D80s compared to the 14B? I thought they were fairly comparable in strength.

 

[Yeller]

@nvrstuk and what was the weight difference?

All I remember was very little

 

[Yeller]

That’s compared to a low pinion 9” though. A HP 9” gets the driveshaft much higher.

Why do you suppose you’ve blown up so many D80s compared to the 14B? I thought they were fairly comparable in strength.

1 ton diesel doing peterbilt work

I do believe you are right, ultimate torque rating on the 80 is more but in my un engineerin’ brain they are about the same.

 

[SC74]

Crazy when you think that the 9” was discontinued by Ford in 1986. I think they are more common now than they were in 1986 lol

Dana’s axles for the most part are still in production with the same parts, let’s not dive into the variants of the 44, 30 and 35, let’s stay with 60’s and bigger.

You mean you don't want me to bring up the benefits of the 8.8 that replaced so many of the 9" applications? That 1986 stat does surprise me though.