Rear Suspension Setup

[Bad Bob]

I'm putting my IRS suspension together on the pan before the body goes on and need some opinions on where to set the toe and camber with no load. I know it will change once it's sitting on its wheels. Here's a pic of the Heim joint pivots I made.[img]

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[petew]

I like!

[Ol'fogasaurus]

Its going to be interesting to see what the wear factor and other things is going to be. A "A" in innovation though.

[helowrench]

I like it. Especially as the spacers on top/bottom can be adjusted for camber.

[Steve Arndt]

Post some more pics, unique setup.

Try for close to zero toe at ride height, just a touch of toe in total.

Camber depends on your total travel, offroad, road race, etc. Close to zero with a touch of negative is usual.

[Ol'fogasaurus]

I've bee thinking on this quite a bit. Based on what I was told years ago about the design/use limitations of the spherical rod end I still have some problem, strength wise, with this. I think I can see good and some weak bits with this design.

What about something similar but use the Uni-ball-joints instead. With a tapered hole in the mount then conical shims in the mount to raise the rod end for adjustment. A limitation to shim thickness being one of the potential downfalls to up/down/max height adjustment. If you weren't worried about adjustability up and down at the pivot point it should be OK.

Just a thought or two.

Lee

CORRECTION I used the wrong term for what I wanted to say. I wanted to say Uni-ball-joints but said spherical ball. I had been taking to someone about spherical radiuses and spherical was typed instead of uni. also corrected to the word "with". Makes more sense now... I hope.

[Bad Bob]

As far as I can tell, this joint only gets a push-pull load. I figured the 3/4" bolt is overkill and could use a 5/8" instead. I started to use the standard aftermarket weld-in IRS pivots, but didn't like the lack of adjustment and hacking the crap out of the frame horns to make them fit. This way, only a couple of tabs were needed. The end of the arm is a piece of 1" bar stock, drilled and tapped for the rod end. I clamped the arms into alignment, and started tacking. The spacers above and below the joint are 1/2" long- easy to make any height needed. Will it work? We'll find out in a year or two when it hits the pavement.
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The gray stuff on the pan is U-POL truck bed liner.

[uglydog56]

Will 1/2" either way make an appreciable difference in camber?

[Bad Bob]

Raising the inner pivot 1/2", changes camber about 2 1/2 degrees.

[uglydog56]

Oh my, 5 degrees of camber adjustment would definitely be worth it!

[PhillipM]

Watch your toe curve if you do that though.

[Piledriver]

Flip that bolt/nut, you want gravity to be your friend if the nut works free.
Better: Weld the nut on.
Best: Weld the nut on and safety wire the bolt.

[Ol'fogasaurus]

Flip that bolt/nut, you want gravity to be your friend if the nut works free.
Better: Weld the nut on.
Best: Weld the nut on and safety wire the bolt.

I forgot to mention that.

"You can lose your nuts but not your head." Crude but true. If the nuts falls off the bolt should stay in place but can work around and can do damage. Better that than the whole suspension falling off.

Remember Murphy's Law: anything that can go wrong will go wrong and at the least opportune/most inopportune time.

[Bad Bob]

I'll probably secure it with a cotter pin. With the body on, the bolt has to come up from the bottom.

[Ol'fogasaurus]

Even with a locking nut I think your idea of a castellated nut and cotter pin is a good idea. Too much at stake there.