Rockwell 2 1/2 Info Thread

SSWaters

Old Member
Joined
Mar 22, 2005
Location
Kannapolis
I thought I'd start a thread on this, I'm guessing there must be at least 20 of you on here that are running these and I just bought my first set. Can we have a common area for ideas and information? Could probably do the same for 44's, 60's, 14B's and 70's.
My plan is to street mine and offroad it when finished, others probably just want to offroad theirs (which would be considerably cheaper).
So far my useful links;
www.whiteowl.com Parts
www.ouversonengineering.com HD Components
www.odiron.com Parts
www.usa6x6.com Parts OUT OF BUSINESS
www.chuckstrucks.net Parts OUT OF BUSINESS
www.longswheel.com Custom Big Wheels, out of Jacksonville, FL. Don't know if they do bead locks but you can weld them on yourself afterwords.
Others are Big Wheel Off Road (Bob), Boyce Equipment, Rock Mafia, bottomland4x4 (Eric V), Aaron871, Mudpro, Firetoy, Ricky and those "Farm/Big Dixe Bogger" guys on this board.
AXLE
I've shaved the pan and put in 1/2" plate. I cut around a 6" diameter hole which gave the Bull Gear around 1 1/2-2" internal clearance (enough for a bolt to clear if one lets go plus enough oil to run the street I hope). Normal dirrection is with the fill plug to the rear.
WMS 79 1/2" hubs out.
WMS 69 1/4" hubs in.
WMS narrowed is 72" I think.
AXLE STRIPPING
RR AXLE

Torch out or grind/chisel the rivet heads FLUSH on the inner side of the backing plate axle flange, smack the backing plate brake assembly with a sledge hammer to drive it off the flange. I've done 14 axles now and this is the easiest way I've found.
FRT AXLE
When taking the king pin caps off, don't lose the spacers under the plate. The spacers go under the top plate. The top and bottom bushing plates are different sizes. They'll stick to the grease and you'll about throw them away like I did.
FRONT AXLE INNER SEAL HOLDERS
Don't waste your time with a slide hammer. If the center section is out slide a 6' piece of pipe all the way through and smack it twice with a sledge hammer, it will sail out of there.
REAR HUB BRAKES
I'm gon'na run "hubs out" so I worked on a low buck hub disc brake set up for the rear. So far I've put in the 8 bolt hub drive pattern in a 2001 1 ton Chevy rear disc (this clears the hub seal) and mounted it to the Rockwell hub. Welded a flat plate extension off of the brake backing plate flange so I can run disc on all four corners. Planning to run 16.5 wheels with 6" backspacing, I figure most people bought their tires for 8 lug stuff anyway so this way they don't have to buy new tires. Can't run a pinion on the front 'cause I want to run lockouts (would have to be locked in all the time for brakes with the pinion brake). Ended up using Wilwoods on the rear since I had already put some on the front. It looked like I could have made a frt. caliper off a Chevy 4x4 fit but didn't persue it once I decided to go Wilwood.
FRONT HUB BRAKES
I had used the USA6X6 wheel hub brake adapters (see bottom of page for new setup) since I had 16.5 wheels, bought the brackets and adapter from Daniel. Bought the Wilwood calipers, disc and pads locally cheaper. If you use these get the 1" longer studs if you want a little thread beyond your lug nuts. If you have 20" or larger wheels I would go with the F550 Calipers and School Bus rotors instead.
USA6X6 brackets and aluminum hat adapters, He's up to $175 now on this, was like $125.
Wilwood Forged Dynalite 120-6814 around $125 each (Summit/Jegs). Rich stated Wilwood "Dynapro 6's" will work also, have more bite.
Wilwood Rotors 160-2894 LH & 160-2895 RH around $50 each (Summit/Jegs).
Wilwood Polymatrix Pads 7112 Series $40 to $175 (depending on compound).
Front USA6X6 adapters, buy the 1" longer studs so you will have extra lug stud thread sticking out. You will have to grind round the USA6X6 bracket edge so it will lay flat against the hub flange.
BULL GEAR
From JP Magazine- 8 bolts around bull gear 105 ft lbs, 4 main caps 175 ft lbs. Pinion nuts 300-400 ft lbs. All bolts are saftied/cotter keyed so they don't back off. Nuts on bull gear face opposite of inputs. One side of the bull gear is chamfered, I put it back in like it came out, on light rigs it probably doesn't matter anyway.
AXLE BOOTS
Get thick one piece ones that last!
HUBS
Inner and outer races are the same PN, bearings are different. Big bearing to the inside, hubs don't care which way they are flipped because the races are the same.
Wheel Bearings - Bearings 3994 and 392
(one of these bearings is the same as a 14 Bolt Gm, let me figure it out again)
Wheel Studs - Euclid brand PN is E-5871-R
Hub Race - Timken brand PN is 3920 (same race using both size bearings so you can flip it)
FRONT AXLE SHAFT U JOINT PART NUMBERS
Rockwell 750N
Precision U joint 898
GMB 230-0075
Size is 5 1/16" across X 1 5/8" caps
CENTER SECTION
I was told by George if you want to flip it 4 bolt holes line up (input to the left or right). You have to drill and tap the housing or drill the center section for the other bolts/studs to mount it.
There is a spacer under the frt pinion yoke and not the rr, don't let it fall out and lose it.
On the trucks the fill hole is to the rr on both axles.
Carrier Race - Timken brand PN is 394AS
Carrier Bearing - Bearing 395 and Race is 394A Timken Numbers, I also got an MS number of MS19081-103 (someone let me know if these are wrong)
Pinion Bearings - Bearing Small 22780 and Race Small 22720, Bearing Large 29585 and Race Large 29521 Timkens
Pinion Seal - 23695 ? (not sure of this number)
HD Chevy rr disc installed on Rockwell hub, Wilwood calipers on extensions welded to axle brake backing plate flange. (hard to see but you get the idea)
awww.steelworksunlimited.com_monster_garage_slides_garage13.jpg

HD Chevy rr disc bolted to the Rockwell hub (drilled in the hub pattern) with calipers bolted to flat plat extensions welded to the Rock flange.
awww.steelworksunlimited.com_salvage_slides_ROCK_20RR_20BRAKE_202.jpg

Welded and filled spiders, ground to balance it out.
awww.steelworksunlimited.com_salvage_slides_ROCK_20SPOOL_201.jpg

My steering assist set up, 8" throw inline with tierod. You can mount this anywhere as long as you get the travel right and centered.
awww.steelworksunlimited.com_salvage_slides_HYDRO_20ASSIST_201.jpg

BELOW Pictures 2/09/12 Front Hub Disc spacer mount idea, using above Wilwood PN's
index.php


Rockwell Disc Brake
SSWaters, Feb 10, 2012


George G. came over to the house and got me thinking about front disc again, this is my after work brainstorming. The spacer replaces the above USA6X6 Adapter Plate.

It would be "hub out only".

If you wanted to run a larger outside diameter disc just make the caliper bracket taller accordingly.

Will probably counter sink the spacer to hub mount bolts or use flush heads (it bolts thru the hub sideways). Kind'a close to caliper like this but it was my first try. I guess you could weld this but I don't like welding hot roll DOM to cast, even if you're certified to weld iconel underwater on the moon or magnesium on venus.

Would use high strength cap head bolts on the rotor to spacer mount, just didn't have any at work. Would safety wire those also, like I did these, don't just trust locktite by itself on the disc.

The disc you have to grind a hair off each tang to slide it down on the hub (1/16" to 1/8"). Don't pay any attention to my scribbling on it.

The spacer is 7 1/2" OD by 1/2" wall DOM, could not find find 6 3/8" ID Tube at an affordable price for the weekend warrior (found it, just not affordable). Will have to grind out little "moons" in the bottom to clear the stud shoulders. ($65 delievered from Speedy Metals last week)

Since I had to go with 6 1/2" ID I shimmed this hub center with 20 gauge sheetmetal plates (Home Depot or Lowes), could use 18 or 22 gauge depending on your hub (I had bead blasted this one clean). 16 Gauge is way to tight, had to really beat in and got all jammed up. Would have went if I had ground the hub surface really smooth. Shim all the way around evenly before drilling hubs! Spacer bolts go through shims.

The Caliper mount is out of 3/8" thick steel, you will need 5" X 10" pice to make this.

Drill some holes, Tap some others, some grinding/cutting/fitting and no welding.
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I use Chuck's trucks typically as a guide of "what not to do" :D

A low-buck wheel disc kit would be really impressive.. There's most certainly a market for it, and it would be some really sweet fab work...

Not much to offer in the way of help other than a few links I have stored at home, but just encouragement..
 
There are several braking and hydro steering approaches to your ideas. I am a fan on the pinion brakes for the ease of installation and braking power, will probably not be the best for you on the road. I have seen the ackerman - sp? - style set up with a double ended ram set up, or people running a 2x8 or 2x10 double acting cylinder with the arm end tapped for a heim to mount to high steering arms - this is the cheapest way to go for full hydro. You will need a new steering pump, orbital valve and cylinder. If you plan on doing rear steer you will need a five hole orbital valve and rear steer control valve. Hope this helps.
 
i'm using older ford dually rotors/brackets on my rear. it's a near perfect combo. as much as i hate to for price reasons and his reputation, i think i'll end up buying a kit for a my front axle from usa6x6. i'm really surprised someone on pirate hasn't come up with a cheap homebrew setup yet. doesn't look like it would be too hard with a little machine work, but i haven't checked it out much. just for comparison, here's what my setup will be:

-welded rear, detroit front
-mohawked front pan, simple flat rear (i have oiling concerns at highway speeds with the mohawk)
-hubs out, 46" xml's on the stock budd wheels. plan to either weld the split ring on, or get a diy 20" beadlock kit. i may end up flipping the centers as well, depending on what overall width comes to. i'm trying to stay somewhere around 90 inches.
-flipped front housing for driver drop
-selectro hubs in place of the drive flanges (damn these are $$)
-eventually full hydro that will allow safe street use (double ended ram, reactive valve, etc.). i was originally planning to do the hydro with the axle swap, but it's taking me so damn long to do anything i may end up doing a conventional setup until time/funds allow for doing hydro. with the front axle nearly 10 inches forward, that may prove to be a challenge though.

i've gotten as far as shaving the housings and mocking up the suspension, maybe one of these days my schedule will relax and i can make some real progress. it's extremely depressing to have a truck down for almost 2 years....
 
I have talked to the guy that runs this set up and it does well - Obviously this is a rear steer, but he has the same on the front. This is a cheaper approach.
 

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cant see pic, red x

Im not into 2.5tons, but I like to see people make things work. On the disks, look into motor homes and school buss for parts applications. Most still had very large rear axles (Dana 80 and up + HD spicer units ) yet needed to be hydralic for DOT reasons. ~Mid -80s or so they started shifting to monster calipers/rotors....

-mik-inda happy with my smallish D60/14b-e
 
check out this thread.... starting around reply 16.
http://www.pirate4x4.com/forum/showthread.php?t=42094&page=2&pp=25&highlight=rockwell
this too...
http://www.pirate4x4.com/forum/showthread.php?t=378384
with the recent popularity of rockwells, someone is gonna get it figured out using parts store piece with no machining.

2.5's just made sense to me financially and in terms of strength. to build a pair of 1 tons to hold up to real abuse under a fullsize, you're looking at 3k+ after gears, lockers, shafts, etc.
 
no pics of mine, sorry... but look in those links i posted, Transgo posted a pic of them installed on a rear. i'm running 20's, so wheel clearance is a non issue. 15's/16.5's really limits what sort of setup you can use and backspacing. what are you shooting for in overall width? with hubs out, wheel discs, and 16.5's it's gonna have to be pretty wide.
 
I know a guy in SC that is running part store front disks at the wheels. He had to cut the outer knuckle and can no longer have the "boot" in place. I'll ask him what parts he used.

As for tech, I'll give up what I got......




Plated the bottoms w/ 1/2"
1371912-a1BendixJoints022.jpg

Welded the inside (for her pleasure)
1371913-a1BendixJoints024.jpg

Started the spools
1371914-a1BendixJoints015.jpg

finished the spools
1371917-a1BendixJoints021.jpg
 
Rims


I started w/ 4 of these
1372151-Customrims002.jpg


And 4 of these
1372152-Customrims003.jpg


I hacked the centers out of these
1372154-Customrims005.jpg


And carefully cut the centers out of these to perfectly match the inside of the old waggon wheels. Notice the precision insturments.
1372153-Customrims004.jpg
 
They fit perfectly. Face down on the factory lip or edge of the waggon wheel.
1372155-Customrims008.jpg


Tack them and check the runout ..... then weld the piss out of them.
1372157-Customrims009.jpg


A little paint
1372158-Customrims012.jpg


6" of backspacing
1372159-Customrims015.jpg



Perfect with double short shaft fronts and the hub's out.
1372160-Customrims016.jpg
 
I need to do a write up on my steering.
Basicaly the front:
stock hydroboost pump ($58)
2.5 x 8 ram Tractor supply ($75)
7.8 cu/in dan foss ($299)
Hoses ($40)

The rear:
2 x 8 ram Tractor supply ($68)
Joystick valve Tractor supply ($75)
Saubaru electric power steering pump Junkyard ($40)
Hoses ($60)


I had to extend the reservoirs of the pumps so that I had enough fluid to run an unbalanced ram.
 
SSWaters said:
Aaron, was gon'na do the same thing with wheels but having a lot of heartache over cut'n some chrome Barts up. Guess I'll go down to Lester's and see if he has any old 16.5 x 14 painted wagon wheels laying around cheap. From your pics it looks like I could run even more backspacing on the front than I thought. I and I bet some others appreciate the pics and info.

Do you just trailer yours or street it to? Reason is, Gazely told me you burn up the pinion seals with the pinion brake on the street. Or are you having better luck?

Scott

Lester want's:
$20 for a 15 x 10
$50 for a 15 x 12

I didn't ask about any 14's. The rims I was looking at were all rusty and beat up (bent at the edges)
I got a good deal on mine (15 x 10's) but I would buy new ones and hack them up before I went to lester for 14's.

I don't run on the street much, but I have a few friends in TN that run on the street with the same rims tires and brake set ups that I do with no problems. You need a detroit in the front to run on the street safely. I have to either use rear steer or do a 4 point turn to get out of the drive way and on to the street. :D That just isn't safe in charlotte traffic.
 
pinion brakes are very dangerous on the street, as is any hydro but top of the line parts, not agri supply specials. check out the threads i posted earlier, some good updated pics of those bus rotors installed. mine are on order :D
He had to cut the outer knuckle and can no longer have the "boot" in place.
how is he addressing lubrication of the joints and kingpins? outer axle seal?
 
RufusTheRam said:
pinion brakes are very dangerous on the street, as is any hydro but top of the line parts, not agri supply specials.

I'm very sorry, I had mistaken this for an off-road forum :wtf:
I will delete my fromer posts with all that "dangerous" stuff in it.

how is he addressing lubrication of the joints and kingpins? outer axle seal?

Well, uhhh, the joints are exposed in any open knuckle front axle :rolleyes:
And the kingpins have grease fittings (at least his and mine do), I thought that was standard.
I have to agree that not running the boot is a downfall, that is why I mentioned it (I use the boots)
 
Aaron871 - I looked at your posts and you have some great tech posted.... Id like to see them posted... (I can undelete them if you want)

As far as RufusTheRam's comments, they are true .... but you've already stated your driving habits. Besides im sure it'd be a kick ass parking brake in conjunction with the disks...

Mike stupid 2.5 ton question of the day - whats the point of the boot ? Im sure its obviouse if you could see inside :) I thought the 'good' axle setup was the ones with large ass u-joints ? or is the boot only needed for the other, bendix? joints?

SSwaters - havnt been to PbB yet this am, but there is a thred going on about disks swaps and locating one thats a close bolt on... Might go post your pic over there...

-mike
 
yager said:
Aaron871 - I looked at your posts and you have some great tech posted.... Id like to see them posted... (I can undelete them if you want)

Thanks,
If you want them posted then thats fine.
But let me make this clear: I don't want to be liable for anyone that uses that teck, and get's in an accident on the way to the Sonic Burger. :beer: :flipoff2:
 
Aaron871 said:
Thanks,
If you want them posted then thats fine.
But let me make this clear: I don't want to be liable for anyone that uses that teck, and get's in an accident on the way to the Sonic Burger. :beer: :flipoff2:

I think we can say that LIFTING your offroad vehicle, etc etc will make it more dangerous on the road, etc. If you are worried about the danger on the road, either make it a trail only rig or leave it stock.... :flipoff2:

Seems to me putting 2.5 ton axles means this isn't really a rig that "should" be driven on the road any longer. You CAN....but as with ANY highly modified rig it is a heck of a lot more dangerous.

Honestly, my rig is to the point I don't like to drive it on the highway...in 2005 I have 20 miles or less on the road...but I am legally tagged, etc.

Good Tech Aaron, thx....
Sam
 
yager said:
Mike stupid 2.5 ton question of the day - whats the point of the boot ? Im sure its obviouse if you could see inside :) I thought the 'good' axle setup was the ones with large ass u-joints ? or is the boot only needed for the other, bendix? joints?

Back when I was really considering them, I think I remember reading that the boots had to do with the u-joints not having seals on them? That, and alot of moaning about how the zipper boots always leak.. :p

Is that correct?
 
Rich said:
Back when I was really considering them, I think I remember reading that the boots had to do with the u-joints not having seals on them? That, and alot of moaning about how the zipper boots always leak.. :p

It's my understanding (or best guess) that the guys saying that their boots leaked, had gear oil leaking because their axle seals were bad or gone. Gear oil should not be finding it's way into the knuckle. My U-joints are N.O.S. and sealed. My kingpins have grease fittings. But, I also agree that it isn't a good idea to let the knuckles get packed with mud and dirt. I think it could destroy the bushing in the spindle (between axle shaft and inner spindle). And possibly let the bearings get wet. I'm running the zippered boots and don't see anything leaking.
 
Aaron871 said:
It's my understanding (or best guess) that the guys saying that their boots leaked, had gear oil leaking because their axle seals were bad or gone. Gear oil should not be finding it's way into the knuckle. My U-joints are N.O.S. and sealed. My kingpins have grease fittings. But, I also agree that it isn't a good idea to let the knuckles get packed with mud and dirt. I think it could destroy the bushing in the spindle (between axle shaft and inner spindle). And possibly let the bearings get wet. I'm running the zippered boots and don't see anything leaking.

Having been on the bad side of a few dozen boots during my time in USMC MotorT (mostly 5T Rockwells), I believe this is correct. The upside to zippers is not having to completely dismantle everything from the knuckle out. You may still get some "leakage" from the various greases seperating, but nothing like a bad seal running gearoil out. We had to change them out whenever the tiniest hole appeared :rolleyes: , but that generally went to a higher echelon shop, unless we were in the field and they were busy rebuilding the engine in some zero's jeep...
 
first of all, aaron my comments weren't directed torwards you specifically so get your panties out of a wad. :flipoff2: if you truck stays on the trails only, fine... you've got a great setup for it. someone mentioned street driving with pinion brakes though, and i was just stating it's dangerous for a number of reasons. a short drive down a barely traveled road, etc. sure it's probably not going to be a problem. but in town or highway driving, no way. this is an offroad forum, but i'd say 90% of us on here still drive our stuff to and from the trails.

the axles need the boot for a few reasons. first, the stock u joints aren't greaseable and aren't sealed. there are aftermarket joints out now that are sealed/greasable though. second, the kingpins aren't sealed. though, you're probably fine just giving them a squirt from time to time. third, there's no axle seal there. this is the biggest dillema.
 
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