Topic: Looking for '83 8" solid axle tube dimensions

[beefyjw]

I'm an engineer and thought it would be cool to do a full engineering analysis on the solid axle front housings and best ways of trussing them out.

However, i need to know the main tube diameter, wall thickness, and ASTM material. Anybody know this?

[jssgbsn]

http://www.pirate4x4.com/forum/toyota-truck-4runner/775780-toyota-bible-faq-2-0-a.html

Not sure if this has what your looking for.  Scroll down to Axle Info section.

Good luck!!

[beefyjw [OP]]

Nope it's not in the Bible. I'm tempted to drill the tube and try and determine it, but i'm assuming someone already knows.

[TacoRunner]

If you've got even a cheap mic you could measure it once the housing is disassembled. No need to drill a hole. Even at Home Depot you can buy a mic for like $40. Not a bad tool to have on hand anyways. And I think you know feelings on what kind of truss to use. Beyond that I would guess that kind of steel being used is better than 1020. Those housings are very strong for how small the tube diameter is and the wall thickness. I have cut them apart before they were a touch thinker than .120" but smaller than .188". But that was measured with a tape measure not a mic.

[beefyjw [OP]]

Yeah. I measured a 3.13" O.D. this weekend. A quick check using 40 ksi steel and .2" wall put it bending when the the majority say 80% of the vehicle weight was on one tire with some impact. Think fully loaded vehicle going down hill with one tire high. If the wall is a little thinner and the steel a little stronger.....that's the same range. I think that's a reasonable design starting point. It's 2x stronger than it needs to be for road use (a reasonable design point for Toyota in the beginning), but is bendable under extreme use (which is important validation because it does bend under extreme use). So far i have a basic idea that doubles, or triples the strength (depending on strengthening member used) all the way down the axle and doesn't obstruct stock mounts, or lose clearance. I'll keep working on it.

[TacoRunner]

1020 steel is 50 kpsi. I'd bet those axles are closer 60.