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Fabbing a frame with full leaf sprung Dana 44's


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Before you guys get too excited I haven't put much thought into it yet, but what do you think of fabricating a frame out of 2x4 .25 wall, essentially taking a Jeep jk or cj suspension design and throwing that on to the frame, then bolting/ welding the whole thing on the bottom of a r50? I know it would take quite a long time but I'm looking for a summer project... Is it possible to do and could I still daily drive it?

 

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I don't think you could daily drive that. It may be illegal without some sort of inspection? You could not tell anyone though...

 

You may have trouble finding reenforced spots on the floor pan to bolt to. You will want to bolt instead of welding, the rubber washers isolate noise and vibration between the frame and cab.

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Seems like you'd be adding a whole lot of weight. I'd look into what people have done to SAS the R50s. I don't think they have to build a whole extra frame under it. And if you can do it without screwing with the rear axle, you'd keep the flex of the five-link. As to whether it would daily drive, well, that just depends on how well you do it. So long as the alignment is good, the steering is set up properly, and it's not sitting so high it tips, I don't see why not. But do keep the consequences of failure in mind, especially if you haven't done a lot of fabrication prior to this. You don't want something to fail on the highway because it wasn't welded right.

 

As for legality, I don't know about AZ, but I know it would be fine around here. We don't even have inspections. So long as the lights work, the tabs are good, and it's not currently on fire, nobody really cares.

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This is some serious hard core fabricating. That being said, it's all been done before. (Maybe not with a R50, but it has been done.) Geometry is everything! You need to have a plan for a few different parts of the build.

1) Frame, build from scratch or start with something and modify.

2) Body mounting, Plan on cutting out quite a bit of the existing under-bits of the R50.

3) Tying it all together, Steering, brakes, etc.

 

I've seen guys in the rat rod world spend 1-2 years getting it all figured out, and that's on cars with much simpler setups. This seems to be a bit ambitious as a summer project. But , PLEASE! do it.

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I think a full frame would be excessive, and I wouldn't see the benefit of removing the existing rear link setup.

 

However...a new front subframe for the SAS portion would be an optimal approach (and one that I've been thinking about myself for a while now). Despite what the R50 is in regards to unibody and suspension, one advantage for an SAS is that the steering, suspension, and drivetrain simply unbolts from the chassis via the existing subframe...clean slate! Nothing to grind, nothing more to remove. The existing strut buckets make for perfect coil, strut, or coilover mounting (I mean, the bucket already serves this purpose, and would not need any new reinforcement), and everything is already cleared for the axle.

 

With subframe removed, you could build a simple frame that boxes in the front radiator support to the existing subframe mounts, and back to the transmission crossmember. Potentially, all bolt on. (It stands to reason if the current subframe bolts already support everything, a replacement frame wouldn't be much different.) A reinforced radiator support provides mounting points for the leafs, and a new crossmember with hangers for the rear spring or rear link mount.

 

You'd also need to add motor mount perches to the new subframe, but with old subframe down, you have the exact measurements you need.

 

Probably the most challenging part will be swapping in a steering gearbox. It would be best incorporate a mounting plate to the new subframe that puts it where the existing pivot gearbox is, but the inner fender area has a structural tube/rib in that area as part of the chassis. It looks like that structural tube is rather square and I wonder if the interior to this is accessible behind the crush cans of the bumper...if so, you could potentially slide in a steel tube with welded nuts to provide the mounting mounts (or through-holes to bolt into the wheel well). Wouldn't surprise me if a Hardbody/Frontier gearbox was compact enough here and shared the same pressure line fitting sizes...and possibly even use the steering shaft from it.

 

If I take an approach like this, I will most likely try to use the OE rear links (at least the lowers) as front links, or any Jeep links. I think the latter are shorter, but there'd be a ton of off-the-shelf options.

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I think a full frame would be excessive, and I wouldn't see the benefit of removing the existing rear link setup.

 

However...a new front subframe for the SAS portion would be an optimal approach (and one that I've been thinking about myself for a while now). Despite what the R50 is in regards to unibody and suspension, one advantage for an SAS is that the steering, suspension, and drivetrain simply unbolts from the chassis via the existing subframe...clean slate! Nothing to grind, nothing more to remove. The existing strut buckets make for perfect coil, strut, or coilover mounting (I mean, the bucket already serves this purpose, and would not need any new reinforcement), and everything is already cleared for the axle.

 

With subframe removed, you could build a simple frame that boxes in the front radiator support to the existing subframe mounts, and back to the transmission crossmember. Potentially, all bolt on. (It stands to reason if the current subframe bolts already support everything, a replacement frame wouldn't be much different.) A reinforced radiator support provides mounting points for the leafs, and a new crossmember with hangers for the rear spring or rear link mount.

 

You'd also need to add motor mount perches to the new subframe, but with old subframe down, you have the exact measurements you need.

 

Probably the most challenging part will be swapping in a steering gearbox. It would be best incorporate a mounting plate to the new subframe that puts it where the existing pivot gearbox is, but the inner fender area has a structural tube/rib in that area as part of the chassis. It looks like that structural tube is rather square and I wonder if the interior to this is accessible behind the crush cans of the bumper...if so, you could potentially slide in a steel tube with welded nuts to provide the mounting mounts (or through-holes to bolt into the wheel well). Wouldn't surprise me if a Hardbody/Frontier gearbox was compact enough here and shared the same pressure line fitting sizes...and possibly even use the steering shaft from it.

 

If I take an approach like this, I will most likely try to use the OE rear links (at least the lowers) as front links, or any Jeep links. I think the latter are shorter, but there'd be a ton of off-the-shelf options.

 

If you're considering SAS I think everybody on here is pretty excited, seeing as you have a tendency to document things extremely thoroughly. Go for it!!! In regards to using front Jeep links, them being too short wouldn't be a concern IMO since so many long arm kits are available.

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Thanks, mjotrainbrain, I appreciate that. That route is a long way away for me (although, there are two D44 Wagoneer axles on my local CL, and one already has a Detroit in it...though I'd put another air locker in it since I'm already set up for it). Plus, there's something else I want to work on before tackling a project like that.

 

As for the links, yes there are a few option for Jeeps. Though, the R50 ones are already much longer, and with OE ones running $36/ea, that price is hard to beat...of course, being able to use that length depends on a few factors. (In regards to the front driveshaft, Nissan Nut's site has a lot of great info about that.)

 

SellOut: regarding your thought of using (rather, replicating) a Jeep setup, this is also something that has cross my mind. The XJ/WJ would, in my opinion, be the best to consider. Driver's side drop, 4-link, narrow diameter coils (and no shortage of length options)...if you could replicate those geometries and incorporate that into a new subframe, that seems like it would be reasonable option. Even a complete donor truck would be affordable, entirely for the suspension parts.

 

The only cons to this I've been thinking about are the width of the axle (I think it might be just a little too narrow), the wheel bolt pattern (adapters exist, and would help with the width), and the strength of the D30 axle. The Jeep community tends to dislike this axle in general because it's not terribly strong...but usually when I see complaints like this, I presume it to mean guys who jumped to 35's, never regeared, and broke stuff. Nonetheless, there are some D30s to avoid altogether (those with vacuum disconnects), while some have potential. An axle truss reads like a should-have option for them, but I feel like this axle would would probably be beyond sufficient for a modest SAS. Plus, these axles are extremely abundant and cheap.

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The only cons to this I've been thinking about are the width of the axle (I think it might be just a little too narrow), the wheel bolt pattern (adapters exist, and would help with the width), and the strength of the D30 axle. The Jeep community tends to dislike this axle in general because it's not terribly strong...but usually when I see complaints like this, I presume it to mean guys who jumped to 35's, never regeared, and broke stuff. Nonetheless, there are some D30s to avoid altogether (those with vacuum disconnects), while some have potential. An axle truss reads like a should-have option for them, but I feel like this axle would would probably be beyond sufficient for a modest SAS. Plus, these axles are extremely abundant and cheap.

 

The only times I've heard of people having issues with XJ axles is when they have 35's+, are locked, and doing extreme wheeling recklessly. With some common sense, well placed upgrades, and reasonable tire size, a D30 would last just fine in my opinion. If there was a way to use an XJ axle then doing an SAS would suddenly become a lot more attainable for a lot more people; Waggy D44's aren't all that common anymore. Only one that I could find for sale, and the yard wants $360 for it, with 2.XX gears and plenty of rust. XJ axles are available left, right, and center for next to nothing. Not that I plan to do an SAS anytime soon though. :(

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The D44 axle can be a tough find, but would be worth it. The axle is closer to the H233B in size (H233B is still a beefier axle all around!) while the D30 is much closer in size to the older R180 than the R200.

 

Rust will surely be an issue in most places (not so much here the desert), given the donor age. And you'll almost certainly need new gears to get close to OE Nissan ratios. Because of that, you'll also have to be mindful of the "carrier break" (the ratio in which a different carrier is required to account for ring gear thicknesses), when thinking about your setup. For 33" tires, 4.88 would be a good match to the OE 4.90s from an Xterra. 5.13 (41:8) gears exist for the H233B, and it's an exact match to a D44 option...perfect for 35".

Edited by hawairish
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I've got two d44 low pinion axles here in AZ. Both are Waggy's. One is a bare housing with chromo shafts, 3.73+ carrier, lock-rite and nothing else. The other is a cleaned axle that hasn't been opened, but has discs, calipers and hubs. I also have some 6-lug Chevy take-off hubs with rotors that are practically brand new along with some flat top knuckles (not machined).

Edited by KovemaN
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Plans for them? Is one of those the one still on CL? There's a guy way out in Apache Junction who's got a Detroit-equipped one, but I was hoping to hear back from the other guy first.

Edited by hawairish
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Plans for them? Is one of those the one still on CL? There's a guy way out in Apache Junction who's got a Detroit-equipped one, but I was hoping to hear back from the other guy first.

No existing plans. Nothing has been posted. Just sold my 5.13 H233b gears.

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If your planning on selling​ the flat tops and Chevy hubs and rotors, let me know. Living an hour from the closet junk yard, I have a heck of a time getting them to call me back when I inquire about flat tops with Chevy 6 lug outers. It has kinda stalled my collection of parts for the SAS.

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I've had the axles for a few years. Didn't mean to hijack the thread, but this heavy stuff is best kept local. No ad out and I wasn't actively trying to sell the stuff, but it's time. My project isn't happening.

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