Downward Facing Square U-Bolt Option for Rear Springs

[SportsBoy]

I wanted to make a thread about this because I think it is a better option than the u-bolt-plate-on-top option that many people use.

I'm sure plenty won't agree, but I like it because:
1 - You don't have to worry about the u-bolts or plate hitting the unibody (maximum articulation)
2 - Easier to unbolt (for me at least) - my impact doesn't fit in the wheel well to unbolt, but would easily fit in to unbolt from underneath if the rear was jacked up.

This was inspired by posts from user "dit" in this thread - https://www.astrosafari.com/viewtopic.p ... 6#p1524716
Here is an example pic -

From dit's post

The gist of this solution is to use -
- A top plate on top of the springs
- Square u-bolts with threads facing down
- An under-axle saddle or seat of some sort to bolt the ubolts on to and to hold everything securely together.

In dit's example, he used:
- 1/2" thick ubolts, ~3" wide inside, 12" long cut to size
- Stock clamshells cut to form "L" shape - acting as both top plate and spacer on the side (since the springs are 2.5" wide and the bolts were 3" inside).

- An extra pair of stock astrosafari under axle seats for the u bolts. These have to be grinded down/drilled out since they have pressed-in studs when you take them off the clamshell leaf spring clam assembly on your stock van -

I am currently working on my install, it involves:
- Ubolt seats and top plates from silverados/sierras in the junkyard.

Like these - gray is under axle seat, black sits on top of the leaf springs and holds the u bolts in place

- More metalwork than I thought
- M14 x 1.5 square u bolts (About 9/16 thick, 2.6" inside width, 11" length, 5.8" thread, grade 10.9) - https://www.amazon.com/gp/product/B072N ... UTF8&psc=1

There are certainly some other options for the metal pieces used in this mod - surely there are other trucks you could take parts from. Like this axle seat from a tundra would probably work for example -

Here are some of my progress pics - you'll see what I mean when I said it has been more metal work than I'd thought.

Drilling new holes

You can see that the drill bit had to grind down on the perch as it made its way through the metal. Otherwise the ubolts would have been too skinny inside to fit over it all

Ground down the perches a bit on the other side

Test fitting to make sure I made things so the ubolts could fit on there

I'm not done yet obviously, but I think that dit kind of had the perfect setup with how he did it. With the astrosafari under axle saddle thingers and 2-7/8 or 3" wide square u bolts, it would be far less work drilling and getting things to fit. The two holes could be drilled just a bit more towards the leaf spring perch than the stock holes, rather than having to measure for new holes at a different distance and having to drill on an angle the whole time. Plus no messing with the other side of the leaf spring perch.
It wasn't too bad doing it with the axle out of the van, but most people will do this without removing the rear end of course, so it would kind of stink to do it the way I did it. Plus having to grind/drill the perches at all isn't ideal (considering that this weakens them somewhat). That's why I think dit's way would be better.

Who else has done their rear leafs like this? What is your setup and what was/has been your experience with it?
(I am using 22-687hd s-10 springs with this for my rear lift btw)

[Mmusicman]

EXCELLENT POST!
I'm strongly considering this option for my 2000!
(unless someone can show good cause why not to)

[icebrrg3rd]

I cut off the Astro perches (for the 3" fiberglass leafs) and welded on some aftermarket perches (2-1/2" wide). The lower bracket is from a 3500 Express, I originally used the U-bolts from it but they were too rusty so I got new ones. Steel leafs were from a 2nd gen Astro.

Side note, it's a Ford 9", the axle tube diameter is larger than the stock Astro 10 bolt so I had to use different brackets. But the overall result is similar to yours.

-Andrew

[MI_Ghost]

[markmitch]

Anyone tried to do this mod and still use the stock rear sway bar? I will get some of these parts and try it later with the sway bar attached to it all. Mark

[pmou]

I'm gonna be attempting this mod, documenting here: https://www.astrosafari.com/viewtopic.p ... 2&start=80

I ordered my bolts from www.uboltsdirect.com -- they have a solid selection.

[AstroWill]

Every time I see this title come up I think of Yoga and this is the image that pops into my head:

[Big_kid]

Same^^

[Ironsides]

I had tried to make that set up work, got it all together but it wouldn't align in the single piece saddle or something, I just went with up bolts, I have extra OEM saddles like dit used, removed the weld studs, but I didn't use them either, can't say why and I didn't write about it. I think the perch spread out the u-bolts and at 75 ftlbs things started bending. I don't off road so it's not critical to me. I like your idea though, it's the extra drilling close on the inside that makes it work.

[pmou]

I decided to attempt this by drilling out the stock under axle brackets... a few hours and a whole lot of drill bits later.. i'm only a bit closer to the goal of this mod. How in the actual eff do you drill out these studs without a drill press? I've toasted a couple 1/2in drill bits, a 9/16, and a 5/8 in the process of drilling out 2 of the stock brackets. Still have 2 more to go if this is going to work out.. and my drill bit budget for this project has long passed. Any tips? I expected to drill out the heads on the studs and pop them out, but turns out they are tacked.

[pmou]

OK --

good idea / bad idea -- use these as under axle brackets? https://www.etrailer.com/Trailer-Leaf-S ... SS300.html



I believe all the dimensions line up -- 3" axle, 11/16" holes already in there so could accomodate up to 5/8" u bolts.. the one question in my mind is how long is the clamshell.. would 4" still place the u-bolts on the clamshell?

edit: i answered my own question -- I read the drawing wrong. overall length is 4", the holes are going to be less than that. I do not believe this would work due to the holes being too close together.

[pmou]

I think I'm going to end up passing on this mod for now... take a little time to gather my thoughts and some parts.

Just food for thought anyone attempting this -- It looks like 1994-2002 Dodge 2500/3500 uses a 3" wide spring and has a Dana 60 rear axle (i believe, may be dana 70) with a diameter of 3.125" (dana 70 is 3.5" it looks like) - This was likely going to be my next idea, grab a set of the plates from a JY to go with the square u-bolts. In case anyone wants to attempt in the meantime. It may be possible to snag the bolts from one of those trucks as well, if used u-bolts are OK with you.

https://www.autoandtrucksprings.com/dod ... ng-btd854/



from that listing

Front Holes to Rear Holes, Center to Center, (4.156"),

Inside Holes to Outside Holes, Center to Center, (3.656"),

Nib to Nib on Half Moon (That Fits Under Axle), (3 1/4"),

U Bolt Holes (.600"), Can Be Drilled To Fit (5/8") Diameter U Bolts,

Fits Up to (3 1/2") Outside Diameter Axle Tubes,

This Bottom U Bolt Plate Fits (3") Wide Rear Leaf Springs Only,

Original Replacement Dodge Lower U Bolt Saddle,

Right Side Left Side Saddles Same.

[markmitch]

I am going to do a combo of some of these ideas, I got the u bolts and the parts for the Silverado but I am also going to try and use cut down sections of the top shells. Only to keep it centered, But I have not got under my van to look it al over since I got the parts but I am also adding a leaf from the 98 parts van just to stiffen it up a bit. Eventually I will buy a new set of leaf springs but this will suffice for now.

[pmou]

Ok, hit the JY today.. looks like 1500s have 2.5" wide springs and the dodge 2500s have 3" wide springs. unfortunately all the 2500s were missing axles/plates/bolts so i didn't get a chance to measure anything or grab a set. I'm going to keep an eye out going forward though

[SportsBoy]

pmou - do you have a grinder? Grinding the stud off on both sides would make it pretty easy to drill out I'd think.

Cobalt drill bits are supposedly bomb, but I don't have those - just regular drill bits and cutting oil (which is important) were fine for me.

[SportsBoy]

Looks like I forgot to add something to my first post - the under axle seats need to be modified to fit btw. Here are some pics of what I had to do.

Like I said earlier - more metal work than I thought when using the under axle saddles from another vehicle.

[markmitch]

What if you were to cut the stock set up minus the part that holds the bump stop then use the Silverado lower parts in place? Then use just the top of the original saddles on top of the spring pack with the down facing square u bolts? That is what I came up with trial fitting yesterday. But my van has a factory rear sway bar I will have to make fit somehow too. Just some thoughts- let us know what you come up with, Mixedgen

[SportsBoy]

Not 100% sure what you're talking about cutting Mark - I didn't want to mess with too much stuff in case it weakened the leaf spring perch though.

[SportsBoy]

Finished this install - seems to have come out well after 50 miles on it.

My only issue was I marked the u bolts with my grinder at 7.5" but actually wanted them 8.5", so they all have a hole in the threads. It's below the nut on all of them so it didn't make a difference though.
Oh, also I wish I had 1/2" or 1" more threads on the bolts, I pretty much ran out of threads on all of them.

I cut the ubolts down to 8.5" - I could have gone to 8" or 7.5" probably. I do wish I had gotten them in 2.7" or 2.75" width perhaps. That would have made it far easier to fit them in the bottom plate since they were being bent outwards because they were too narrow for the perch.

Used these poly leaf spring isolators from Energy Suspension (3.6112G) between spring and perch and spring and top plate

Pretty diddly darn solid feeling I'd say.

The under axle saddles from the silverado are for a 3" (I think) axle shaft (ours is less than that (2.75 maybe?) so the saddles fit, but have a bit of room. I think when I tightened down the bolts it actually bent the saddle to fit the axle tube. I'm not 100% on that, but it looked like that was happening. Hopefully I'll never have to take these off again to see. Unless I replace the ubolts so they are a better fit, but meh.

[markmitch]

So you put the poly things on top but is there steel on top of that? I mean the u bolts are sitting on the poly or did you add steel between them?