So I've been bouncing back and forth on what to do with the Bronco. My current setup is still running the D44 and 9" combo. Both front and rear housings are trussed and braced. They're stuffed with 4.88s, spooled in the rear and Power Lock up front. I have disk brakes all the way around, did the 1 ton GM steering conversion. Overall it's a great setup, but with 37" tires it's definitely taxing the stock axle shafts. I have broken a couple of them, I generally wheel it fairly conservatively. I find myself having to take it easy on it in certain situations to avoid grenading something. The general consensus of this rig is, it's overpowered, overtired, and under-axled. Sometime down the road I plan to build up a big horse 460, possibly stroker 514, 521... So I'm trying to decide if I should go the rest of the way with the 5 lug stuff and shove some RCVs in the front and 35 spline Mosers in the back. That or take the front D60 and Sterling rear that I also have, and load them up with gears and lockers. What do you guys think?

 

37s is totally doable with half tons and aftermarket axle shafts. I ran 39s on 31 spline aftermarket shafts for a long time. But nothing lasts forever. If bigger tires are in the plans, do the swap. If not, run what you have.

 

Have you priced rcvs lately? You can do a 1ton swap cheaper. I know you can throw money at the d44 and the 9 but it's still 1/2 ton. Moving up in axle gets you more than a bigger axle shaft. Axle tubes are thicker, full float rear axles, bigger bearings, brakes you name it. If you are planning a big inch engine you'll probably break no matter what you put in if you try. If it's not a street rig do what I did and buy Rockwells. Only thing is a 40 or 42 is all the smaller you want to go with those.

 

I think a lot of people drink the Kool-Ade and put 1-ton axles in where they really aren't needed. But I don't think this is one of those cases. 37" tires have to be taxing the half ton brakes, and you've said that the torque is already causing breakage. Like nitemare said, the 1 tons will do a lot more for you than just give you stronger shafts. I vote that route.

 

Bigger axle tubes isn't a point to look at if his are braced and trussed already. Like I said, being he's already got them, shafts isn't that big of a deal. It all depends on his tire size goal. 37s aren't very big for 1 tons, so his ground clearance would be less. If bigger tires are in the plans, than yes, swap away. If not, upgrade what he has already invested $ into.


I'd never jump onto the Rockwell train unless 47s or bigger where my goal. Plus the added lift you need to clear the diff is a lot sometimes. 44s run nice on one tons, the wt difference between rocks and tons isn't worth it imo on 44s.

 

Thanks for the input guys, much appreciated. I guess I should have been a little more specific on what the rig is used for, sorry about that. My goal for the Bronco is to have a well rounded machine. I use it for trail riding, mud bogs, sand dunes and street driving. The whole idea was to make it capable of nearly anything, and yet be comfortable and reliable enough to drive daily if needed. So far I think I've hit a home run. A couple things about the current 1/2 ton setup that bother me, first and foremost the brakes... this has been enough of a reason for me to pull the trigger on a 1 ton swap. The tiny 1/2 ton brakes are simply not enough to get this 3 ton behemoth stopped in an acceptable manner. The front having a limited slip, actually has worked very well for me but I have found myself in situations where I wish I had a front locker more specifically a selectable locker. The fact that it's a lightweight axle with tons of ground clearance is a big plus. The two weak points of the D44 that stick in my head are the small axleshafts and u-joints and the small diameter pinion. To my knowledge there is no real fix for this, RCVs would only fix half the problem. I've seen many sheared/twisted off D44 pinions, the deeper the gear ratio the weaker they get. The 9" I have a lot more confidence in. It has the Yukon nodular center chunk, Daytona pinion support, solid spacer, has the bigger carrier bearings and caps, etc. Short of stuffing it with 35 spline cromos, it's pretty bulletproof. I love everything about it, but I find the spool somewhat annoying for street driving. I think I would be happier with a Detroit Locker, or something comparable. In the scheme of things it would make more sense to stuff a D70 or a Sterling back there and set the nice built 9" aside for a different project. I guess that's kind of where I stand on the current setup. I would like to eventually go up in tire size, 40s-42s probably stick with the TSL Swampers they have served me well so far. I have in the back of my mind the thought of having a set of 40ish" tractor tires for it for bogging. I think if I stay around that size, a set of tons shouldn't have too much trouble handling it. Power wise I would be happy to have a pump gas burning BBF pushing around 500 hp and 600 tq. The brake issue should be pretty much resolved when I do the hydroboost conversion.

 

Well to me it sounds like you have your mind made up on the one ton swap already. Lol


Word of advice on the tractor tire, they take way more power to spin in the mud than a TSL. Like so much so that I use my doubler a lot in the mud with my tractors on.

 

Well I don't see it being feasible to get much more out of the 5 lug stuff without spending big bucks. Not worth it to me. If it was strictly a dune rig, I'd leave it be. I have been kicking around the idea of doing the 203/205 doubler and a twin stick conversion. Also swapping 1/2 gearset from an E40D into the C6. Do you think even with 5.13s and 40" AG's, Id still want a doubler?

 

Possable, with the motor your planning on, no, but with what you have, yes.

I run some that measure 42.5 tall, I've got 5.38s and my motor is kinda tired though. In the thicker stuff I can't spin them without the doubler. Than my buddy runs 42 tsls with 5.38s a mild 350, TH400, 205, and he could spin the tsls like mad, put same tractors I have on his and could hardly turn them.

 

I'm currently running a basically stock, but healthy 460. It has a mild camshaft, Performer RPM intake, headers, and custom built/tuned Holley DP 950 carb. It runs out pretty strong, put a hurting on my buddy's 1st gen Cummins which is no slouch either. Are you still running a 351m?

 

Yep, sure am. It's gettin tired now though. it's bored out, shaved heads, big cam, 750 cfm, headers and some other odds and ends. It got up and went really good when I had it in my old wheeling rig with 44s on it. These tractor tires take a lot o power compared to them 44s I had. Lol

Rebuilding a 400 for it soon. Lol.

 

Have you considered looking into the oiling system mods for the 335 series motors? I'm sure people already hound you about going to a 460. There's actually some pretty bada$$ parts out there for the"M" motors. As much as I love my 460s I like seeing people building up 351m/400s. I've seen some very strong 400s out there, build em right and they run like a ****.

 

I've never had a issue with oiling on mine as of yet. I think I have some broken rings for horrable valve guides. It uses oil like mad right now. But it's used and abused it's whole life. It use to run out to 7500 Rpms no prob, but now it starts floating valves at 6000 or so. I like these "boat anchors". I really don't think a 460 would fit in this Jeep very well, there's Just enough room for this 351M. Plus I had to build custom headers n motor mounts to get it in there. Lol. I like these motors. I've had really good luck with it. And no, not a lot of people hound me about a 460, when this motor was fresh, a lot of people thought it was a 460 untell they actually looked under the hood. Ya I know no replacement for displacement, but I have a odd "love" for the 351M/400. Lol

 

I guess the reason why I mentioned the oiling issues, it was a known problem in this engine family. A lot of people write them off as boat anchors, when in fact they don't really know what they're talking about. I've done a fair amount of reading up on the 335 series, there are fixes for most of its weaknesses. I tell people, they can't be too bad if Jon Kaase chose a 400 as the base for one of his Engine Master's build off engines. I'm kind of an "against the grain" type of guys myself. A majority of my 4 wheeling was done with a 300 six and a granny 4 speed. Talk about a bulletproof setup! I love the big cubic inch motors, but something intrigues me a 400. When did you build a Jeep? What happened to the old crew cab?

 

I vote 60 front 70 rear. That what I'm planning on running on my current build. I'll only be running 39.5s until I can pony up the cash for a set of 42s. 42s seem to be a conservative number without taking all the reliability out of a set of axles that are not completely built. Plus I'll be running my 460 as soon as I find the cash to get everything else I need for my C9 heads