until I break one Im calling BS.


I can break a bowling ball in a sand box with a rubber hammer.

 

Somthing being weak doesn't mean its going to break! All this means is somthing in one situation is stronger than in another. Why would they call it a power and a coast side if they were equally as strong in both directions. The only was possible to have a gearset that is equally as stong in one direction as it is in the other is to have straight cut gears.

 

which are noisy as hell.


So then I guess you must agree (through the numerous explanatory replies -thank btw) that just because "something being weak doesnt mean its going to break" means that it wont necessarily hurt anything to pull with a truck in reverse.



Ive got to say Ive never thought of it this way. I fully understand how gears work but Ive never thought of the coast side being weaker on a HP axle. I like learning new things....now if I could just remember all the things Ive forgotten.

 

I agree it won't nessicarily hurt it but it could happen so if you have the choice do it going forward.... Breaking parts cost lots of money and who really has money theese days? I avoid situations where I could break somthing unless I have no choice or it looks cool

 

Nah, I wanna see you fubar the gears in George! Frame to frame, facing each other, pulling in reverse with my stupid duty, on asphault?

 

Is tying off to the bumper ok?
What if i weld a recovery point to my front bumper does that help?

 

It is harder on the drivetrain to pull someone out while you are in reverse. The front end is getting more of the load and the front end isn't as tough as the rear end. No myth.

 

^^^ thats for sure.

I do have to add however, that the ring and pinon are stronger turning in a designed direction. If yall actually understood what was happening as those gears were turning, and how the direction of the cut effects how the gears mesh and the load points.

But yall are to interested in fighting to see that.

and as for high vs. low pinon. It has more to do with the oiling the pinon bearing. A low pinon places the bearings in the the oil. When you move the pinon up, you have to make provisions to oil the pinon bearings. As for strength a low pinon is stronger, but you lose clearance for your drive shafts.

Now wether or not the difference enough to really notice, probably not. It would probably take some serious beating. As most have said, you break other parts first.

 

eeeeeeh.....wrong.

So you are saying a D60 rear is stronger than a D60 front? Hop aboard the failbus.


I think I do. I never thought about the coast side being weaker though.

eeeh, maybe.

Why is this a problem? A rockwell pinion is completely above the ring gear.

Ill let you keep that secret to yourself.

the first sensable thing youve said.

 

Any steerable axle will ALMOST certainly be weaker then a non steerable equivalent. But not in regard to the center section. U-joints are the weak point.

I beleive that the rockwells are a little different. They do have a ring and pinon but it drives the gear reduction gears instead of the axle. And as long as its oiled its fine.

The reason a i didnt say much about pinon position, is becasue it depends upon alot. And it has more to do with the strength of the center section it self and the pinon trying to walk up the ring gear. which is more common on the drive side of gears. So it doesn't really apply to backing up

Most of this is irrelavent in relation to the drive vs. coast side being weaker or stronger. But who care as long as im right

 

I do because you arent!



As Alpha/Omega said, using a Dana 60 as an example, the only item of comparible strength is the ring and pinion. Every other component is weaker in that rear axle compared to the front.


I agree Rockwells are a different animal but the statement still stands that the pinion is above the ring gear. If oiling were an issue Im sure the military wouldnt have used them so long.

If in a HP application you are worried about the pinion "pinon trying to walk up the ring gear" in drive then you should be aware the pinion is trying to walk down the ring gear in reverse for LP applications.


LP axles are not stronger than HP axles in the front of vehicles. In most every case the LP axles are weaker than their HP axle counterparts. IE LP D60 vs HP D60. Sure it also has to do with the crappy parts used in the LPs but Ill take a stock HP 60 over a built LP 60 any day of the week.




Alpha/Omega, Im diggin' your username but I need to inform you that its inaccurate. I am god.

 

So your saying that its harder to break an axle shaft with a u-joint is stronger then a solid straight shaft. Umm, i cant even begin to believe that. The u-joint size may be increased to help condensate for the weak point. But it helps not to have a weak point to begin with. The Dana 60's might be an exception.


Yes the R&P on a rockwell is above the axle. All that means is that when the axle was originally designed it had oil passages to allow oil to get to the bearings at the top of the gear set.

The reverseing does not cause the pinon to "walk down" the ring gear. It would cause it to push away from the ring gear laterally.

And as i said, it depends greatly on the set up of the deferential. If its HP Reverse Cut, or LP reverse cut, or a HP or LP regular cut, each will produce a different result.

 

Jesus H Christ!


you do realize dana 60 front axles are 1.5" and 35spline and Dana 60 rear axles are 1.31 and 30spline dont you?

I can break D60 rear shafts quite easy. I havent broken a D60 front shaft yet. Granted the yoke/ujoint is the weakest link but it doesnt mean its weaker than a 60 rear shaft.


Do you think a HP axle doesnt have provisions for oil? A bearing sitting in oil has parasitic drag. I doubt they would make windage trays for engines if this wasnt an issue.


I dont know what the ring and pinion is doing. Ive never crawled my *** up in through the diff cover to check it out.







Heres the deal...

dont build weak **** and you wont have to worry about it breaking.

 

i never said the dana 60 front was as strong as the dana 60 rear. I said that the front wouldnt be as strong as the rear equivalent. Which would be the dana 70 or ford 10.25. Which both are massively stronger then the dana 60 front.

I am saying that a HP must have provisions for oil. And yes, oil does have parasitic loss, but the bearings in the rearend are moving just a tad slower then the engine, and they have alot more load, so it is better to have them submersed.

I have worked pretty hard to learn all this stuff, most of the mechanical aspects iv learned by taking stuff apart and looking at it. But when it comes to the physics, geometry and math behind how it really works. I'v studied alot to learn that. Which is what i mean by knowing what is really happening in there. (Although it would be cool to crawl inside and see it. Im a nerd.)

Im tired of all this bickering, but im glad that we both have the same view. I just make sure its big enough and heavy enough that it wont break!

 

Alright guys maybe I can help, I think I can make this pretty simple. First of all, the guys who say it's bad to pull in reverse are right and I can prove it. Here is the coast side of a tooth on the ring gear: /|... here is the drive side: |\ Pretty much looks like a triangle, right? Now which side of the triangle is better supported, the straight up side or the slanted side? Obviously the straight up side... which is the drive side. The problem that comes with pushing against the coast side of the tooth, with enough torque load the angle of tooth can actually force the pinion away from the ring gear causing it to chip teeth and break other stuff.
I am not looking to insult anyone's intelligence, just simply trying to put things into perspective for those who aren't grasping the physics of the situation.
I admit, I am guilty of pulling people out in reverse too, like someone else said situation dictates. Given the choice I will always pull going forward. I'd much rather use my winch though.
Stuff can definately break when you do this, I watched some dumba$$ kid blow the whole front diff assembly apart, case and all in his Chevy Z71 1500... pulling someone out in reverse.