If I wanted to hear someone talking out their azz I would have farted. 2.5 ton Rockwells do indeed come with drum brakes as well as some models being available with pinion brakes. Pinion brakes are a BAD idea for the street as they get very hot and are not designed for high speed since you're only using 2 brakes instead of 4. If you don't have a clue (which appears to be the case) call Boyce Equipment or USA 6X6 and they can fill you in.

Here's an interesting little experiment you can try at home if you want to test your theory as to gear ratios and frame twisting: Take a 1/2 drill (don't use a weeney 3/8) and clamp a socket extension in it . . . a nice long one. We'll pretent this is your driveshaft and the drill is your engine. Now find a socket that fits over your lug nut and attach it to the extension. The lugnut represents a poor gear ratio like 4.10's with 49's. It's much harder to turn the pinion on a ratio like this vs. a higher numerical ration like a 6.72. Now we'll pretend your wrist is the frame. Hold the drill with 1 hand, very tightly and hit the trigger. Yes, that snap you just heard is your wrist (frame) breaking. Go tape it up and try the same experiment with your good wrist and a valve cover bolt. Let me know what you come up with.

 

You mean if he wants some more wrong information?

Yea, Cleatus, your truck is cool, doesn't matter that some guys don't get the "big" thing. The coolest thing is that you did all the work yourself

 

actually, I don't think you are 100% correct either.. I think that pinion brakes where invented by rockcrawlers who wanted to lose the extra weight.

 

actually, I don't think you are 100% correct either.. I think that pinion brakes where invented by MONSTER TRUCK BUILDERS to stop the huge tires when the drum brakes couldn't, way back in the 80s before anyone even used rockwells on rockcrawlers.

 

Yeah rockwells being used in rock crawlers is a fairly recent thing. I'll have to dig up the info I have on the 2.5's. I think Bremen is partially correct but it seems I remember something about pinion brakes being used in the old M series. However something in my hazy mind is making me think these pinion setups were used as a parking brake only, not a stopping brake.

 

I think you better at least look at a set of rockwells before you start giving advice about them. And as for re-enforcing your frame it should be done if you go off road at all. You "could just weld in a few suporting cross members to your frame around the shackles " But I would build a subframe by bolting pieces of angle to the frame to weld to, then build a subframe similar to what the monster trucks use, running from the rear of the front springs to the very back of the frame with as many Triangulated crossmembers as you can get in there.

 

They are parking brakes,but THEY ARE DRUMS MOUNTED ON THE TRANSFERCASE, not on the axles

 

Gotcha Jesse. I knew that the pinion brakes they used were no good for stopping a vehicle but couldn't remember the details. That explains it.

 

as you dont seem to understand it is the power combined with weight causes rockwells to destroy frames rockwells would do this even if they were not geared as low but the low gearing speeds up the process. example you have a dana 44 or 60 with low gears you get a tire up in the air and you are hard on the gas when the tire hits the ground with all kinds of torque but the axle shaft breaks. in a rockwell you get a tire high and when it comes down it has all kinds of power when it hits the 2.5ton axle shafts are strong enough to handle all the torque so something else has to give the power is transfered through the springs to the frame and without support you get cracks which lead to breakage if overlooked that example doesnt even take into account what happens when you have the suspention flexed out which is when things really break because the power which is combined with the leverage of having all that weight so far from the frame.
you are probable right that there are versions of the axles with wheel brakes but all the ones including mine that i have ever seen have pinion brakes granted all the ones i have seen are on rockcrawlers currently
jesse460 i agree with you that for off road use you need a very serious frame to handle rockwell i have a friend that runs them under a jeep/s10 hibrid and he has a fairly build frame and it still puts cracks in his frame regularly and that is exactly why im building a full tube frame to put mine on.

 

Don't compare a Jeep frame to an F350 frame . . . not even in the same neighborhood. What you are talking about is driving style and suspension style. It has nothing to do with the kind of axles under the rig. As was previously pointed out properly equipped 2.5 ton Rockwells are not significantly heavier than the stock 1 ton running gear.

First off: Offroading your rig does not mean "jumping" it. If you ARE jumping a rig then one would expect you have enough common sense to know what you're doing and you won't be standing on the gas when you hit. Not even monster trucks do this and they are running 5 ton Clarks and Pettibones. You also need to consider that if your friend's piece of jeep is cracking frames he probably needs to re-examine the kind of suspension he's using or at least how it's set up (in addition to the fact that he strapped 2.5 ton axles to a tin can). It doesn't even take a fancy 4 link system to accomodate this. If a leaf spring suspension is properly designed there will be no problems.

 

I KNOW I AM RIGHT, you previously said "first off Rockwells do not have wheel brakes. the brakes on rockwells are off the front of the differential" All rockwells i have ever seen come with drum brakes There is not one OEM application of rockwells that come with pinion brakes. All pinion brakes are aftermarket kits, or custom fabricated. And when it comes to 49 inch iroks and the torque of a powerstroke axles shafts could be broken easily off roading, I have broken rear shafts in my jeep with 2.5 ton rockwells and 44s.

 

Sorry to get you guys in a fight over Rockwells!!! Really! It's no big deal. I know I don't NEED Rockwells. My stock axles will suffice with the 49's, it's just that I WANT Rockwells. Not to off-road or mud bog, or rock crawl...just to "Have what no one else has!!!!" Besides, my stock suspension WILL NOT off-road. It is low-tech leaf springs on a 9175 lb. truck. It's designed to be the tallest, biggest, and most roadworthy it can be while being huge. It does that. It does it well.

About the pinion brakes/drums on Rockwells:
The M35 series trucks (deuce-and-a-half) used drum brakes at each wheel. The parking brake was mounted on the transfer case as a drum. Pinion brakes are used for their simplicity, light weight, ease of installation, cost, and the fact that for mud-bogging, they are easy to clean. They are not a good idea on the street because while they do work well (braking force multiplied by 6.72), they do not have the ability to stop the wheels equally. In this I mean that there is a differential between the driveshaft and each axleshaft. In the case of unequal traction between the two tires on the axle, one may lock up while the other spins freely or even tries to spin backwards. This can be messy. Montana law (as such with many other states) requires a brake to be mouned at each wheel/axle shaft.

Thanks for the kindness Pro!!

Cody

 

Shhhhhh, lets keep that on the down-lo, Cody. Wouldn't want people to think I'm going soft

 

There you have it. If you don't like it, then you don't like it. I haven't asked anyone what they think, I'm just showing/telling how it is. Look at it this way; it's like an issue of OFF-ROAD magazine. You see these huge vehicles that have no use whatsoever except to get attention on the cover. You may not like the truck on the magazine cover, but you buy the rag anyways (only FTE is FREE!).

I guess the reason I'm pushing my Giant-killer on all of you is because there is no one around my home that really respects or admires the kind of work it takes to make a vehicle "YOURS". Gotta stay ahead of the competition. Anyone who has any kind of time, money, fabrication, modification (better or otherwise), lumpy noggin, or blood/lost knuckle skin knows what it's like to stand back after an entire weekend of wrenching and admire the difference they've made in their vehicle....just to go back to work on Monday. I respect people who can work on their rigs and improve upon its function, performance, looks, etc., etc. I especially enjoy reading about the WAY someone modified it and gets graphic about the process. I'm a technical person. I like to work with my hands and tools and enjoy figuring out how to make something work while still being SAFETY CONCIOUS. Heck, I lose sleep about some of the crazy ideas I come up with. So that's me in a nutshell. Thanks to those who have been supportive/inquisitive (not saying anyone hasn't) and have a Happy Christmas and a Merry New Year!!!

Wait.....
I'm not going anywhere.


Cody

 

Cody, just so I don't have to smack you in the mouth take a look at this:



Yes, leaf springs and over 10,000 pounds . . . and they still race it from time to time. Not to say you could go nuts without putting your tires into the fenders but there's nothing wrong with leaf springs.