good tech. Thanks!
and for the other bit, up above regarding stinkbug and caster,
1 deg stinkbug means 1 deg less caster. simple math. It's a bit over 1" at the ends of the rockers or side steps to make 1 deg difference.
How to measure castor?
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good tech. Thanks!
and for the other bit, up above regarding stinkbug and caster,
1 deg stinkbug means 1 deg less caster. simple math. It's a bit over 1" at the ends of the rockers or side steps to make 1 deg difference.
I do not think measured caster is as simple as a one to one relationship with the angle of the trunion bearings (or any angle you want to relate to it).
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It's not exact, but is close and is relative, X amount of axle angle change = close to X amount of caster change. In this case it doesn't really matter. When using stock arms in the stock location, there is only so much adjustment available, so just need everything that you can get, without the arms interfering with the tie rod.
Well, I measured very carefully and rotated the axle back one degree by measuring off the trunion bolts.
I made some larger washers out of 1/4" plate, drilled the holes to the exact size of the bolts so there was no play, and welded them in place. The welds aren't huge so I can make some adjustments.
The truck does drive noticeably better. The death wobble I had has gone away almost entirely, but there's still a bit there when I go down hill at around 50mph. Freeway driving felt great, and hard breaking was a lot better too. Before the truck would dart back and forth when I hit the brakes from a high speed.
So, Maybe move it back just a bit more? All I have to do is cut the welds, rotate just a bit, and tack it back.
I made some larger washers out of 1/4" plate, drilled the holes to the exact size of the bolts so there was no play, and welded them in place. The welds aren't huge so I can make some adjustments.
The truck does drive noticeably better. The death wobble I had has gone away almost entirely, but there's still a bit there when I go down hill at around 50mph. Freeway driving felt great, and hard breaking was a lot better too. Before the truck would dart back and forth when I hit the brakes from a high speed.
So, Maybe move it back just a bit more? All I have to do is cut the welds, rotate just a bit, and tack it back.
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I do the test drive before tacking, allows for playing with the setting before welding. But it's easy to cut the welds.
I figured the washers would move if I did that.... Oh well, I put the welds in a spot to where they could be easily cut.
I've just fitted a set of Superflex arms to my 80 (with 4" lift) to replace the factory arms and caster plates due to the amount of interference I was getting between the rear steer rod and the radius arms. Now there's no problem with that, but I'm noticing that with the much less restricted articulation, there's a fair bit of bump steering and tram tracking happening. Haven't had a wheel alignment done yet since the superflex arms were fitted a week ago. My panhards are EFS adjustables with poly bushes, so the bushes could be dudded. Checked/adjusted wheel bearings just a few days ago.
Talk of caster and camber is always interesting. One of the things I find fascinating is that because the kingpin bearings in the swivel hubs are not lined up vertically, any time the front wheels are turned away from 'straight ahead', their entire geometry will change, since you're turning the wheels around non-vertical axes on each side. And as the vehicle is driven, the steering is already not operating in a 'level plane' so any changes to the plane on which the vehicle is driving feed back into the suspension and steer in unusual ways.
I'm aware that very small amounts of wear/play in any of the steering components can have quite a noticable effect on handling, particularly with a significant lift and larger than std tyres/wheels.
I've never paid a lot of attention of how wheel alignment machines measure things, but since tow is the only ex-factory thing that's adjustable, and caster is affected by lift, most places don't understand how this might affect camber as that's a big contributor to tyre wear, just like incorrect toe.
Talk of caster and camber is always interesting. One of the things I find fascinating is that because the kingpin bearings in the swivel hubs are not lined up vertically, any time the front wheels are turned away from 'straight ahead', their entire geometry will change, since you're turning the wheels around non-vertical axes on each side. And as the vehicle is driven, the steering is already not operating in a 'level plane' so any changes to the plane on which the vehicle is driving feed back into the suspension and steer in unusual ways.
I'm aware that very small amounts of wear/play in any of the steering components can have quite a noticable effect on handling, particularly with a significant lift and larger than std tyres/wheels.
I've never paid a lot of attention of how wheel alignment machines measure things, but since tow is the only ex-factory thing that's adjustable, and caster is affected by lift, most places don't understand how this might affect camber as that's a big contributor to tyre wear, just like incorrect toe.