Rockwell axle drivability

[snakeater]

who here has done a rockwell conversion on their m-715 that is street driven. If I decide to go bigger (no time soon) the next logical step is to rockwells. My question is are any of you that have done this conversion driving them on the road? I am basicaly looking for option of steering components that make it roadworthy. Most vehicles that i have seen that use 2.5 ton axles are trail only because of full hydraulic steering. This isn't worth it for me. I see lots of posts on here of people using them. Are the pinion mounted disc brakes stout enough for daily use? Lots of questions concerning this and no answers...........Snakeater

[503m715]

I have rockwells under one of my trucks. It is not drivable yet though.I am using 46" xzl's and ram assist for steering. I want to drive my truck on the street, so I am building my own wheel brakes. I will say that pinion brakes will not work well for the street. They will get very hot real fast. You will also have to be locked front and rear and would be better if spools were used. (with an open diff you run the risk of only one wheel grabbing at a time per axle) For steering you can use a ram assist set up. Look up Tom Lawlor's(spicergear) M715 from the 2005 top truck challenge. 4x4 magazine did an article on it. It might answer some of you questions.

[Jester]

http://www.ouversonengineering.com/home

[Jester]

spicergear's truck

[Barrman]

Tom kept his steering very simple when he first did the conversion. He actually finished the job, drove 15 miles to pick up his girl friend and then drove 800 miles at 60 mph to meet a bunch of us at LBL in Kentucky for the 2004 National FE. He had 11.00-20 tires on it then. His 427 Tall Deck got right at 10 mpg that trip according to him.

Doug's head is kind of in the way, but you can see most of the steering set up in this picture I took:
[IMG][/IMG]

[gun512]

Just curious why the next logical step is rockwells?? Unless for the case of cheaper rims and tires is what you are after.

[randyscycle]

I've driven a couple of different street driven Rockwell equipped trucks, and they both had normal power steering, one had a hydraulic ram assist. The one with the ram assist did steer a bit better. As far as straight down the road, they drove just fine, but with the 6:72 gears, you will definitely need overdrive. I'd stay away from full hydro on the road. While it isn't illegal, it should be. If there is any kind of hydraulic failure, you don't have any steering at all. That and they are vague at best when moving along at road speed. Best left to the rockcrawlers in my opinion.

In a deuce they don't have power steering, just a really big steering wheel. Standing still they are pretty nasty to turn, but moving they steer OK.

The tires are the biggest factor to overcome in steering with Rockwells. While the axles are pretty big, the knuckles are surprisingly not all that huge, and can be run with a regular power steering box.

Oh, and keep in mind too, that if you add Rockwells, you will also be adding a ton of weight. They are heavy! You can counter some of that by doing a disc conversion.

Kamakaze built his truck with Rockwells too. He could give you some advice as well.

[gun512]

Just did some googleing on weights of rockwells versus the dana 60/14b combo

14 bolt around 550lbs.

Dana 60 fully dressed single wheel front Chevy 60 complete, locking hub to hub 518lbs

Rockwells

A fully stock front axle, with the heavy drum brakes weighs..... 842lbs
With the massive drum brakes taken off they weigh in at ........ 682lbs

A completly stock rear axle with brakes weighs in at .............. 692lbs
A rear axle with the brakes stripped off weighs in at ............... 532lbs

The center section with the gears is the heavy part at.............. 220lbs

The Dana 60 info came from Pirate 4X4, the 14bolt weight came from wikipedia and the rockwell weights came from rockwellrigs.com

Accoring to those numbers you are looking at roughly 130lb additional in the front and 25 pounds rear (if you went to disk brakes). Not sure if the numbers include driveline brakes instead of drum's.


Also, Snakeater i know a guy in Tullahoma, TN that sells alot of rockwells if you ever need a referance.

[Kamikaze12volts]

who here has done a rockwell conversion on their m-715 that is street driven. If I decide to go bigger (no time soon) the next logical step is to rockwells. My question is are any of you that have done this conversion driving them on the road? I am basicaly looking for option of steering components that make it roadworthy. Most vehicles that i have seen that use 2.5 ton axles are trail only because of full hydraulic steering. This isn't worth it for me. I see lots of posts on here of people using them. Are the pinion mounted disc brakes stout enough for daily use? Lots of questions concerning this and no answers...........Snakeater

Mine is street driven and 100% street legal in Canada .... Have a custom build steering arm ( will be building another for a fellow member ... so i can build more then just one ) I'm running 42" military tires with power steering conversion .. even my 7 years old kid can turn those big rubbers. Maybe for extreme off roading you can just add a ram assist if you feel the needed. Btw i'm limited to 60 mph because of stock motor but with my 6bta swap i will be able to hit at least 75 mph without problems. At 55 mph i just keep a finger on the steering wheel .... so for the "roadworthy" i think it's not even a problem.


The arm reused the stock conicals washers for strength and are made 1" thick. Pm in you got any interest having one build ...





Also ... my truck weight exactly 7430 pounds and i'm still using stock drums brakes and can lock thems on dry pavements but i changed everything starting with a hydroboost and a very big master ,3500 HD 1 9/16 of bore

If you want ... look at my buildup tread ... you may find some answers and some solutions having a street legal M715 on rockwells

Canadian build up !!!

[walkers4x4]

Full hydro on the road with rockwells and big tires is definitely scary to say the least. At least on mine the valve will either be a little left or a little right of center. So I am constantly correcting back and forth. If it gets out of control at speed you can get into a driver induced oscillation. It makes you look like your drunk driving down the street side to side. I would definitely go for hydraulic assist if you are planning on using your truck both on road and off.

I haven't had many issues with the pinion brakes on the road. I haven't driven it a lot on the road either. I have detroits in both axles and the pinions are capable of locking up the tires no problem.