random idea of the day: solid rear axle with adjustable camber

so I've been extra bored at work this week and that leads to thinking about random stuff. that lead me to camber on a solid axle. I have no idea if it would even be beneficial enough to be worth the work to do but here it is.

<img src=""

this is roughly what it would look like if you were looking straight down at the axle. its a very crude picture but you get the idea. you would take a 4x4 solid front axle, cut off the end of the axle tubes and rotate them 90 degrees so that your knuckle now moves up and down instead of left and right. then you would have to weld mounts on the tube (blue dot) and make adjusters (green lines) that went from the mount to the knuckle where the tie rods originally were(blue dot), this way you could adjust the top of the knuckle back and forth to move the camber in and out.

like i said this is completely hypothetical,i just thought it was a cool idea. let me know what you guys think.

That is a neat idea. I think it could work, but you would have to design a weird set of control arms to control it.

Also, you would potentially have to swap the gearset for a rear friendly rotation.

Wicked heavy, and the kingpin angles would provide some funky toe changes. Other than that...Clever.

boulder_dweeb wrote: Wicked heavy, and the kingpin angles would provide some funky toe changes. Other than that...Clever.

Do they make knuckles for front axles that have zero kingpin inclination? If not, that's a very good point. You definitely could not deal with toe changes that severe.

I am not sure on the 'heavy' part, though. I doubt it would be that much heavier than the rear axle from the same vehicle.

Find an old late model rear axle and use these. Wide 5 wheels would look very cool out on the street.

http://pitstopusa.com/b-4787-134710-winters-performance-products.html

tuna55 wrote:

boulder_dweeb wrote: Wicked heavy, and the kingpin angles would provide some funky toe changes. Other than that...Clever.

I am not sure on the 'heavy' part, though. I doubt it would be that much heavier than the rear axle from the same vehicle.

Front axles are very heavy compared to rear axles of similar strength. Plus the diff would be offset to one side instead of centered. I don't think most solid front axles had adjustable camber, I think fords did though. It would get you some wicked huge disc brakes in the rear.

It would work, but it would be mad heavy and you would indeed get big toe changes.

I think I have a better idea: Consider what happens when you bend an axle to get a different but fixed amount of camber. My idea is adjustably bendable axles.

You sawzall off the axle tubes right near the diff housing, and reattach them with bellows to hold the fluid in (or just the dirt out, where applicable) and a beefy hinge mechanism that lets them move vertically. Then attach your adjusters between the top or bottom of the diff and the tubes. Voila, same effect (for small amounts of camber - your system would allow a solid axle to run Oni Kyan while mine only allows similar amounts of camber that could be had with axle bending), not quite as heavy, doesn't add anywhere near as many parts, and no toe changes (although with a more complex and heavier 2-axis hinge mechanism with another pair of adjusters, adjustable toe could be possible as well).

But what's the point?

Adrian_Thompson wrote: But what's the point?

I figure getting adjustable rear camber where swapping to IRS would involve changing the suspension completely - it would be less work.

Here's a diagram of my idea:

Red: Bellows covering cuts in axles

Purple & yellow: hinges for vertical movement

Blue: New mounts for adjusters

Green: Turnbuckle adjusters

Adrian_Thompson wrote: But what's the point?

one really doesn't need actual adjustable camber, you need to change it once and leave it. My Alfa friends tell me that they get much better handling with 0.5deg negative camber in the rear- which they can do by bending and using the slop in the axles.

But once changed, there's no need to change it again.

Seems to me that a different end would do the trick- so where you bolt the bearing onto the end of the axle, you can have that turned a little. Or use some tiny spacers- so that you can put in a little toe in, if that helps.

That would be a far simpler mechanism, and similar to how cars adjust suspensions on some set ups.

Shims/spacers is way cheaper, lighter, simpler, etc than using a mechanism.

I agree that in practice "bend once, run always" is a better solution.

Isn't all of this just describing how to take a straight axle and turn it into an IRS?

(except for alfadrivers comments)

wvumtnbkr wrote: Isn't all of this just describing how to take a straight axle and turn it into an IRS? (except for alfadrivers comments)

Nope it just gives you adjustable camber, not independent suspension, and if your car runs some suspension type that doesn't work with IRS, you don't need to re-engineer the rear suspension from scratch,

GameboyRMH wrote: Here's a diagram of my idea: Red: Bellows covering cuts in axles Purple & yellow: hinges for vertical movement Blue: New mounts for adjusters Green: Turnbuckle adjusters

i do like your idea but the problem i see is the hinge/joint that is on the axle inside the tube. these would have to be custom made, one off axles which would be pricey. also you lose the rigidity of the whole axle, when one wheel hits a bump that force is now transferred though the adjuster instead of across the tube.

gearheadmb wrote: Front axles are very heavy compared to rear axles of similar strength. Plus the diff would be offset to one side instead of centered. I don't think most solid front axles had adjustable camber, I think fords did though. It would get you some wicked huge disc brakes in the rear.

GM used a threaded insert to adjust the alignment on the SFA 4wd pickups.

Basically a threaded sleeve with the hole for the ball joint stud offset. It required a spanner type socket to adjust.

Depending on the level of adjustment required, you might not even have to rotate the flanges, just adjust the sleeve.

The offset center section isn't as much of a problem if you use a RWD center and replace the tubes with the 4wd tubes. Axles might prove a bit more challenging.

If you kept the manual hubs you could tow it with all four wheel on the ground.

In reply to GameboyRMH:

okay, I get it. Each wheel will not move independently. However, what is the benefit here?

Just adjustable camber? Seems a bit much work for little payoff.

alfadriver wrote:

Adrian_Thompson wrote: But what's the point?

My Alfa friends tell me that they get much better handling with 0.5deg negative camber in the rear- which they can do by bending and using the slop in the axles. Seems to me that a different end would do the trick- so where you bolt the bearing onto the end of the axle, you can have that turned a little. Or use some tiny spacers- so that you can put in a little toe in, if that helps. That would be a far simpler mechanism, and similar to how cars adjust suspensions on some set ups. Shims/spacers is way cheaper, lighter, simpler, etc than using a mechanism.

i dont like the whole idea of bending/shimming a solid axle for camber, just doesnt sit in my head quite right. even if its just for a little camber your axle in the tube is still straight and would be putting a good amount of extra load on the wheel and carrier bearings i would think.

In reply to wvumtnbkr:

Yeah just adjustable camber, and I also think it would be a lot of work for a small payoff vs. just choosing one setting and bending the axle to it.

wvumtnbkr wrote: In reply to GameboyRMH: okay, I get it. Each wheel will not move independently. However, what is the benefit here? Just adjustable camber? Seems a bit much work for little payoff.

yea thats what i was trying to thank of of a good use for it. i would think that the best application would be something with fat tires that sees a lot of lateral G's in hard cornering, and even then a small amount of camber is all you would need i think.

or so truck guys could join the stance club...

edizzle89 wrote: i dont like the whole idea of bending/shimming a solid axle for camber, just doesnt sit in my head quite right. even if its just for a little camber your axle in the tube is still straight and would be putting a good amount of extra load on the wheel and carrier bearings i would think.

I don't think it changes the bearing loads any, but it will very slightly misalign the side gears.

<img src="" />

black = axle tube/carrier, red = axle, blue = bearings

this is what i think of when i think of bending axle tubes, it probably wont affect the wheel bearing so much but it puts the axle at an angle going into the carrier bearing and to the spider which would put more load on both pieces.

obviously this picture is an exaggerated bend so maybe only doing ~0.5 degrees of camber isnt enough to cause wear issues. in my head it just seems like its asking for trouble

edizzle89 wrote:

GameboyRMH wrote: Here's a diagram of my idea: Red: Bellows covering cuts in axles Purple & yellow: hinges for vertical movement Blue: New mounts for adjusters Green: Turnbuckle adjusters

i do like your idea but the problem i see is the hinge/joint that is on the axle inside the tube. these would have to be custom made, one off axles which would be pricey. also you lose the rigidity of the whole axle, when one wheel hits a bump that force is now transferred though the adjuster instead of across the tube.

I'd have the hinge outside the tube, but you're correct that it would have to be custom made and the adjuster would have to take some forces that would have been transferred through the tube before. It might be best to use double adjusters on the top & bottom.

Edit: Another idea: Multi-hole adjusters on the hinges, like what you see on wing mounts.

In reply to GameboyRMH:

so are the hinges just for the tube? i thought they were on the axle shaft itself like this:

if no then it goes back to the bending axle concept

edizzle89 wrote:

alfadriver wrote:

Adrian_Thompson wrote: But what's the point?

My Alfa friends tell me that they get much better handling with 0.5deg negative camber in the rear- which they can do by bending and using the slop in the axles. Seems to me that a different end would do the trick- so where you bolt the bearing onto the end of the axle, you can have that turned a little. Or use some tiny spacers- so that you can put in a little toe in, if that helps. That would be a far simpler mechanism, and similar to how cars adjust suspensions on some set ups. Shims/spacers is way cheaper, lighter, simpler, etc than using a mechanism.

i dont like the whole idea of bending/shimming a solid axle for camber, just doesnt sit in my head quite right. even if its just for a little camber your axle in the tube is still straight and would be putting a good amount of extra load on the wheel and carrier bearings i would think.

Actually, if you add just one slightly flexible joint on the outside- which your idea has, too- then you can use the shim idea.

then again, the loads the bearing see are large enough that a minor change due to an angle alingment would be pretty minor, I think.