Hey all so specing things out before I begin this process but I’m planning on doing Duffs suspension with the 4 link rear and wanna do full width axles. My question is if I’m doing all this work should I do a high pinion 44 or just do a Dana 60? I’m only gonna run a 37” tire and wanna do the RCV axles in either and an ARB cause we drive in a lot of snow on our Forrest service road/ driveway. How would the swaps be and is it worth the effort or should I stay closer to original width? Thanks all

Or does anyone think no 4 link and just stick to leaf springs? I’m really torn on a lot of this. Wanna get the truck done and running but want to grow into its ability rather than be limited in the future?

I've heard so many people say they are "definitely sticking to xx tire size" only to watch them go bigger sooner or later. Here is my take and the reason I did what I did on my bronco. I 4 linked mine(full custom, not duffs) and 3 linked the front(was still on radius arms for a long time with the rear 4 linked though). I, personally, love stock width, or close to, axles. I built full custom axles at the exact width I wanted which is 64" wheel mount to wheel mount.

Here is why you should 4 link...a properly built 4 link will not only flex better than leaves ever will but, the more important thing, is it can be built to actually help you crawl and stay more stable. A lot of factors have to go into to make it work right though. I'd hope duff's has done that and will be close, but I doubt it's ideal. As with any suspension, everything is a compromise. They're probably setup to handle both street and offroad with an emphasis on street. There is definitely a difference. The main thing being anti squat. I built mine to have around 65% anti squat. The reason for this is push the front end down while climbing. Lower anti squat pushes the front end down in most situations. On the street most people aim for 100% anti squat. Stays nice and level under acceleration that way. Higher than 100% will transfer power and weight to the rear axle. Great for drag racing, horrible when climbing. I don't know how much engineering duff's put into their system but they certainly can't accommodate all the different setups out there as differences in wheelbase, tire size, lift height and vehicle weight will change the setup pretty drastically. But, I'd guess it's still going to give you more ability than leaves will.

I'd go with a Dana 60 if I were you. It sounds like heavy crawling is in your future so you will want the strength. Ideally a 60-9 hybrid axle is what you'd use as you have more clearance than a Dana 44 and more strength than a Dana 60 but they're big $$$.

I like somewhat narrower axles as they allow you to pick your lines offroad a bit better. A buddy of mine is really wide which means he hits his diffs a lot more and is much more limited in where he can crawl.

Leaves are hard to beat for simplicity though. Lots of very capable rigs out there still on leaves. But I'll always recommend a properly setup 4 link.

You'll end up with 40s before you know it.

I would agree with Crawler in that you will probably go with a bigger tire than you think. I planned for 35's but immediately went 37s and even had thoughts of 40s. (that went away quick. The truck wouldn't fit in the garage any more)

I like full widths. I like going proportionally wider as the truck gets taller. Full widths are ~65". Jeep JKs matched that stock. Jeep JLs are now 67" wide for a Rubicon package. That is what the OEM did for a stock height rig. There is stability in width. Full width Ford axles generally imply tapered big bearing 9s and high pinion 44s. Both desirable for strength and driveline geometry. Given that you want to snow bash with 37s (or 40s), you would be safer with 60s. I stuck with HP44/9, but I'm light-footed.

Personally, I prefer mulit-link suspensions, but that's a can-of-worms and there really is no such thing as an off-the-shelf solution. Each vehicle is different and has its own dynamics considerations. Many don't realize it, but just changing tire diameter forces a re-tune of the suspension geometry and shocks.

My opinion, whatever that is worth, is that the traditional triangulated 4-link is not well suited to street or mixed use driving. It's true home is in racing with high-vertical-travel suspensions. For street and trail use, a 3-link or parallel 4-link with with track bar is much better suited. A track-bar equipped suspension will out-perform the triangulated 4-link in terms of ride quality and tune-ability. I throw in tune-ability because you can divorce the various aspects of suspension design, therefore reducing compromises. Again, that's my opinion. It's not shared by everyone.

Again, I would agree with Crawler about his statements regarding anti-squat. I would also point out that with a multi-link you can control roll axis (f/r) and overall roll axis, under-steer gradient, roll rates, recession/precession etc. Things that are important to safe street driving and overall ride quality.

Any benefit to running a Currie Anti Rock or similar to help street manners on a 4 link?

Sorry for the thread highjack, I am currently considering going down the 4 link route and was considering the anti rock for the rear. Looks like maybe I don't know enough about the dynamics of this though.

ORI struts mostly negate the need for a sway bar. They completely transformed my bronco on the street and offroad when I went to them from coils all the way around and even coilovers in front and coils in the rear. It still has some body roll but it's less than I had before and it's perfectly predictable and drives quite comfortably at any speed I've had it at. 75 mph even. Fun fact: they even handle accidental jumping at 45 mph. I had an anti rock and a tk1 sway bar on hand to install after all my suspension work. Those are both sold and long gone now. I could probably utilize one still and be even happier with how it drives on the street but I'm never going to find out cause I'm quite content with my ORIs.

Another question is, do you plan to extend the wheel base? If so, they I think you should consider a multi-link suspension as well. If not, 11-leaf spring packs flex quite well. And, if you can design the Spring rockers into your setup, you can flex even better while eliminating the bind caused by flexing springs. And, you can buy off-the shelf stuff and get it going sooner than later.

The big draw-back is, you may need something to control axle wrap, but that isn't a tall order either.

As to axles, if you think you are going to stick with 37's, even if just for a few years, I don't think it's bad to start there. And if you decide to upgrade later, your HP44 will have significant value if it is in good shape. As to RVS's - you might want to check into their maintenance requirements. I know they are strong, but I heard recently that they are a hassle to maintain. I just hadn't looked into that myself. There are nice Chrom-o setups that will survive 37's if you're not rock bouncing!

As to width, I too like a narrower (closer to stock) width as there are some places that you are stuck to one line with full widths unless you have buggy style flex. But if you can add wheelbase, you can get some of that stability back that you might have had with with full widths.

My buddy has RCV's on his J/K and hates them. They are strong and handle his 37x13.50 tires, but they are a pain in the ass to maintain. He said if he could go back he would not have done them.

I went HP D44 and 37's. It's about the max for the axle, but I can't fit bigger in my garage. Long term goal is a 609, but this was a cheap way to go a little wider and maintain a bunch more ground clearance than a D60.

Full widths can be a nice addition and with decent backspacing won't be too much wider than stock. Which also really helps the front end stay out of the radius arms at full lock with 37" tires. In my experience the D44 isn't going to live with 37" tires and a manual transmission, unless you go to RCVs. (and for the nay-sayers, I'm talking about wheeling, not street queens. Rigs don't break in the garage....). You can beef it up by putting in better shafts, etc... but it's still going to break. The first time you back up and the weight transfers to the front end it'll break the drivers side shaft.

So that means, for me, I would put a D60 in the front looonnnngggggg before I spent the $$ for RCVs in a D44. The only time I'd not do that is if I already have a very well built axle that just needs a little more. I seldom have that since I build complete rigs, wheel them a bit and then start over with a new project... I should sell some of them, bit I just usually don't.

Another option, vs. the 609, would be to do 44/60 or the Jantz 654 front axle. I'm running a 44/60 front and my next step would be to install the Jantz kit if I tear up my ring/pinion. It isn't that hard to build a hybrid axle, just takes a few tools/patience. A HP D44 is much closer in strength to a Chevy D60 at the ring/pinion compared to a LP D44.

In my case, my current project is a Ranger and the front is a HP D44 center section, with a 35 spline ARB, 4.88 gears and D60 balljoint inner/outer C's and 35 spline inner/30 spline outers. Yes, that's deliberate since I will run 30 spline Yukon lock-outs and expect it to be the fuse. I went with the hybrid because in the long run, it's cheaper to find a HP D44 vs. HP D60 and almost all of the other costs are equal, AND... I have better ground clearance and @100# less weight. The rear is a True Hi-9, 35 spine inner/outer full-floater with Ruffstuff weld on flanges and D60 spindle/hub/rotor and Yukon 35 spline lockouts.

What I cannot tell from your sig is the weight of your rig in trail form. The heavier it is, the more I'd lean toward the D60 or Hybrid. I tend to build lighter rigs, the buggy is about 2700# on Krawler reds.

As far as the 4-link question, I agree with Crawler, I would shy away from the Duff "kit". Not saying it isn't OK, but it really is a toss-up on how well it'll work for you. I would design my own (several of us can help if you want). I run a bit more anti-squat than Crawler does, I prefer between 80-85%.

On the sway-bar. I run one on my buggy, but I probably don't need it. It totally depends on what actual 4-link design you run. Double triangulated and with ORIs, you should not need. Parallel upper links and no panhard bar, yes, you'll need one, especially with coil-overs. ORIs are nice if you like to tinker and/or the weight of your rig stays roughly the same, but if you often change the load of the rig you won't like them over time. That's exacerbated if your rig is heavy. ORIs only work well up to a certain load. If they tell you to invert them based on the weight of your rig, don't change anything once you get them dialed in...

Leaf springs are easy and relatively inexpensive, but have lots of issues in heavy rigs, big motors, etc... especially at stock wheelbase. They are a nice compromise for a mostly street rig and level 7 or so trails. Much beyond that and I'd want a linked setup.

So many thoughts in one thread...
HTH, Joe

Wow thanks for all the feedback... apparently I have more to consider than I thought. I’d love to do 40s but was told by Protofab that the rear bumper we are going with will accommodate up to a 37 and I like having a spare tire. I currently have 1.5” wheel spacers that push the tires out a bit so I’m basically hoping for similar width or a touch more but what you said about being able to pick lines makes a lot of sense. Also thanks for the RCV thoughts. I wanted them because of their warranty but where I’m moving we won’t have power or running water for a few years so constant maintenance should ideally be as low as possible when possible. So if not the duff kit who should I deal with as far as helping build and properly set up a 4 link? Also it’s a daily driver but it’s Leadville so a small stretch of highway to town but that’s about the only time I’d even exceed 50mph

I had also considered doing a fabricated 9/60 hybrid front but felt that I was quickly over my head in terms of building it as I’m a spirited learner but by no means a real fabricator or mechanic

This is THE BEST DEAL YOU WILL EVER FIND...

https://denver.craigslist.org/pts/d/den ... 67062.html

I'd pay that just for the 44 disk brake conversion parts.

Of course I missed out as I was in Florida. Is there anyone good in the Denver area to set up a good 4link rear matched to a duff armed front? I’m not wild enough to need coil overs so I’m thinking cool springs still? Or not if I’m told otherwise?

I've got the perfect pair of coilovers for sale....

https://www.facebook.com/marketplace/it ... 922076619/

Matched pair of axles from a 75 f100

Axle has drums but will be a welded wedge heavy tube axle. And price is right

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