Sound Like A Good Idea?

[Ace]

I got this idea from a guy named Anthony over at DTR, but had ideas for a couple variations:

http://www.dieseltruckresource.com/dev/ ... t=rcc+lift

Truck's got the 2" Skyjackers on now, but I'd like to get just another inch lift up front to level the truck a bit (rear sits higher) and make sure it'll clear 35's when that time comes. But I don't like the idea of bolting another 30-pound crossmember in there. And I cannot seem to source any higher grade steel (4340pht) for the shackles at this time. Do you think it would suffice to substitute 3/8" x 1.5" regular flat bar steel for the shackles? Also, I have some 1" thick T6 aluminum plate I was considering using for the front mounts. Just install a 4.25" x 6" piece on each side as a bolt-thru spacer. T6 is higher grade, harder aluminum.

Whatcha think?

[Philip]

Its not my prefered method. I would just replace the springs with a set of 4" lift.

But if your wanting to do it that way. The slugs he ran his threw bolts threw. Weld them into the square tube. The next thing I would do is cap the ends of that square tube. If those bolts come loose for any reason that tube can start deforming without end caps and the slugs welded in.

I wouldn't use aluminum.

[Ace]

The next thing I would do is cap the ends of that square tube.

That's one reason why I figured a solid block of aluminum would be both lighter and stronger. The main thing I'm concerned about is the shackles. They'll only be one inch longer. The springs are fine, only a couple years old, and it only need one more inch to be right where I want it. I've heard some say a 2" lift will clear 35s, so I figure 3" would certainly do it, plus give it a nice level stance. 2 inches more might be an inch too much.

[jensenkennels]

Its not my prefered method. I would just replace the springs with a set of 4" lift.

But if your wanting to do it that way. The slugs he ran his threw bolts threw. Weld them into the square tube. The next thing I would do is cap the ends of that square tube. If those bolts come loose for any reason that tube can start deforming without end caps and the slugs welded in.

I wouldn't use aluminum.

X2

MADDOG

[Philip]

Alumn is still alumn. It doesn't matter if your working with A356, 2000, 4000,6000, 7000. They all act almost the same. It will compress. It will work away from a contact point. It will crack under heavy repeated loads.

A suspension mounting point is not a place I would want an alumin mounting block.

In that pic it looks like he used 3/8's bolts for the mountings. I would have went bigger. Those slugs should be at least twice the size of the bolts. For a 3/8's bolt I would have used a 3/4" slug.

He also didn't repair the rusted frame hanger. If you notice it isn't even touching the mount he made. It has a big layer of rust between it and the mounting block. Rust is not a good support. I would have removed that bad support and made a new one.

The 3/8's flat should work for the hangers. I would weld a support brace across the hanger if your going to be off roading any. Use grade 5 bolts. These will stretch and bend. A grade 8 will not stretch or bend. It will break with no warning.

[Ace]

I would weld a support brace across the hanger

I figured I'd just weld in a cross-brace of the same stock right in the middle of the shackle - make it a one-piece unit. The stock shackles are 5/16, so I figured 3/8 made a little longer this way should be at least as strong, regardless of the steel grade.

I don't see compression on the aluminum being an issue in this particular application. I mean, that's why we re-tourque lugs on aluminum wheels. This is a big surface comtact area on a basically non-moving part. A fine thread bolt with nyla-nuts re-checked every so often the first few weeks until it seats is not gonna go anywhere after that. But I will definitely use 1/2" bolts, if not maybe 9/16, depending on how the meat around the rivet holes looks after I get them out. I also plan to drill the bolt holes to a very close tolerance snug fit.

As far as the bolt grade advice goes, you may want to check out this little article on rockcrawler.com:

http://www.rockcrawler.com/techreports/ ... /index.asp

Considering the rest of Anthony's work well, yeah rust is rust, it's an easy obvious nitpick I wouldn't quibble about on a mud vehicle. And considering he ran that piece of rec tubing clear across both frame rails I seriously doubt there's any danger of it deforming in that application under any circumstances. That's one big heavy honkin' piece of steel! And also the main reason I was trying come up with something a little different - without buying new springs!

[Philip]

He might have ran that tube all the way across. But the bolts are still in the very ends of the tube. That is the weakest part of the tube with those slugs being loose fit.

I have seen just about every type of failure that you can think of with square tube. On a limited use vehicle for off road or mudding it might hold. On something over the road I wouldn't go that way for a lift.

[GO OVRIT]

I doubt you'll be able to get much of a cross brace in the middle of the shackles. Only being one inch longer isn't going to allow enough room at full compression. On the front I made one out of 3x6 box 3/8 wall. I didn't use any sleeves, but rather bolts on the top and bolts on the bottom so I could move the hangers ahead some.(My Alcans are about 1 1/2" longer than stock) Nowhere is the frame nearly that beefy, so I'm not concerned with doing it that way.

[Ace]

Yes, that occurs to me, now that you mention it. I'm going to look at ways to work around that. Maybe something like making the shackles two inches longer and try to see how a brace might fit and work OK in some odd position.

Or just keep looking for better steel. Anyone know where to get tool-grade steel?

[Ace]

So in my metal research for this project (hopefully completed this week - all the parts should be onhand by tomorrow) I learned the 6061 T6 aluminum I have is actually the same alloy most forged aluminum wheels are made of. Now pretty sure that's not going to be an issue. I also found some info on a shackle fab method where they have tabs to keep the bolts turning in the bushings instead of wearing against the shackles. I've got some mild steel 3/8" flat bar I'm gonna go ahead and use like that and see how it goes. I'll post a thread with pics in the projects section after I get it done...