Castor problem?
- Thread starter blakesrover
- Start date
david despain
Adventurer
true though that may be, they are still professionals and not amatuer.
i took the original statement to infer that marc is just a hack that chops his truck up willy nilly. that is simply just not the case. i have seen some of his work and its not just parts thrown together, its not mere fabrication, it is beauty and art. and it is most definitly well thought out
R_Lefebvre
Expedition Leader
I won't argue against that point.
Just to be clear, I make NO comment about Marc.
I still disagree with this. Just because you make money at something does not mean that you are more than an amateur. The word Professional bears much more responsibility than just the fact that you earn a living at it.
Steve Rupp
Observer
Greenmeanie- from the way people think on this board, one broken arm is enough to make people's minds up. I'm still waiting for someone to find a broken stock arm. All everybody likes to do is make claims with no experience.
As far as re-drilling the swivels or "slotting" as you like to call it, I find it really hard to believe that these will rotate.
As far as re-drilling the swivels or "slotting" as you like to call it, I find it really hard to believe that these will rotate.
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RonL
Adventurer
As an amateur wrench and a clueless engineer, let me say that all of these ways will work, but the only "true fix" for caster and pinion angle is a combination of both redrilled swivel(for caster) and bent control arms(for pinion angle).
Swivel housing bolts are holding in "clamp load". If this "clamp load" fails the joint goes into "shear load". At this point it does not matter if you have slots or factory holes, these bolts are going to fail.
Remember another thing, these trucks did not have the best tolerances from the factory. I would bet the swivel housing holes side to side are mis-aligned more then we want to know. It is almost impossible to keep large weldments like axles from wrapping when welded. I deal with this thing every day.
These are not jetplane or rocket ships, a little mis-alignment will not send you falling from the sky.
Swivel housing bolts are holding in "clamp load". If this "clamp load" fails the joint goes into "shear load". At this point it does not matter if you have slots or factory holes, these bolts are going to fail.
Remember another thing, these trucks did not have the best tolerances from the factory. I would bet the swivel housing holes side to side are mis-aligned more then we want to know. It is almost impossible to keep large weldments like axles from wrapping when welded. I deal with this thing every day.
These are not jetplane or rocket ships, a little mis-alignment will not send you falling from the sky.
greenmeanie
Adventurer
Steve,
The redrilled items you show are good as the fabricator has thought about the rotation problem and has placed a full bushing in one of the holes. I have no problem with that mod.
In the original post mentioning this solution no mention was made of that as a necessary part of the modification.
My issue is not which arm is best but more that a single photo without any context for the failure is used to dismiss the aftermarket arms. Was it under normal operation or was it being pushed to some extreme?
R_Lefebvre
Expedition Leader
How can you say that? First, bolted joints are almost never assumed to be friction fits. They are always analyzed as if they are frictionless, and the bolts are full loaded. In this case, there's a shear load from the rotation, as well as a tensile load on the lower bolts due to the cantilever loading of these parts at the end of the axles.
How could you assume that the bolts were not designed to withstand the shear loading? I guarantee you they are. Nobody would design a joint like that with friction being the only thing resisting the load.
That's why you machine AFTER welding. I don't know that that's what they did, but that's SOP for low tollerance weldments. Leave enough meat on the parts, weld, they machine it to bring everything into place. Given the importance of caster side to side on the handling of the truck, I'd think that's what they did. Unequal caster leads to the truck pulling to one side.
As for those parts... I don't like it, it's a hack, but it's probably fine.
RonL
Adventurer
When I said "clamp load" I am not talking about "friction fits". I am talking about bolt torque. We torque bolts to get a specific bolt stretch. This is what gives you "clamp force". The bolts will not fail right away but if they are loose it is only a matter of time. I have seen this happen with loader tractor with the same type of joint that Rovers have.
Machining after welding does happen, but if the axle is drill in two different set-ups, one end at a time. Tolerance on hole alignment from "end to end" may very as much as +/- 1 degree. I doubt they drill both ends at the same time.
All trucks have un-equal caster. Just look at any report from the Alignment Shops. I have never had one of mine end up prefect side to side.
Machining after welding does happen, but if the axle is drill in two different set-ups, one end at a time. Tolerance on hole alignment from "end to end" may very as much as +/- 1 degree. I doubt they drill both ends at the same time.
All trucks have un-equal caster. Just look at any report from the Alignment Shops. I have never had one of mine end up prefect side to side.
R_Lefebvre
Expedition Leader
Ok, I think I get what you were trying to say. Yes, the bolts must maintain their stretch. This is a very well understood bolting phenomenon. When bolts have a light clamp load, cyclic loading ends up cycling them through tension and compression. This fatigues the bolts and they will fail. If they are heavily clamped, as the load cycles, the bolts only cycle between heavy tension and light tension. There is no force reversal, and the fatique curve is much much longer. They don't fail because of the shear, they fail because they are cyclicly loaded and not stretched.
When the holes are slotted, bearing area is greatly reduced, which could lead to mushroomed holes which allows the tension to relax.
Regardless, this mod is probaby fine for the limited number of vehicles we're talking about. But I guarantee you, if you did this to 10,000's of vehicles, there would be some failures, which is why I find it so ironic that the people supporting this mod are critical of the few failures on the LR3.
When the holes are slotted, bearing area is greatly reduced, which could lead to mushroomed holes which allows the tension to relax.
Regardless, this mod is probaby fine for the limited number of vehicles we're talking about. But I guarantee you, if you did this to 10,000's of vehicles, there would be some failures, which is why I find it so ironic that the people supporting this mod are critical of the few failures on the LR3.
proper4wd
Expedition Leader
I am not going to bother reading all 6 pages of banter carried over from the LR3 thread; there are differing ideologies on this board that epically clash.
BUT, the ongoing argument about the broken aftermarket (QT Services) radius arm is moot. That photo was taken by a friend of mine at his (very highly regarded) Rover shop in New England. In this thread on Pirate4x4, he explains the failure: http://www.pirate4x4.com/forum/showthread.php?t=738603&highlight=broken+radius+arm
Excerpt: "The arms were made by QT. Turns out that the fully drilled arms were made as display samples. Somehow this set ended up on a truck. The vendor that sold them has since gone out of business.
Dave Marsh at QT has been more than helpfull in correcting this issue and supplying new arms. "
BUT, the ongoing argument about the broken aftermarket (QT Services) radius arm is moot. That photo was taken by a friend of mine at his (very highly regarded) Rover shop in New England. In this thread on Pirate4x4, he explains the failure: http://www.pirate4x4.com/forum/showthread.php?t=738603&highlight=broken+radius+arm
Excerpt: "The arms were made by QT. Turns out that the fully drilled arms were made as display samples. Somehow this set ended up on a truck. The vendor that sold them has since gone out of business.
Dave Marsh at QT has been more than helpfull in correcting this issue and supplying new arms. "
Antichrist
Expedition Leader
Reading that thread I see they apparently sold more than one set of radius arms intended for display only.
I wonder how you tell the difference between a display model and a real one. Seems like something one would want to know since they seem to get mixed up.Pirate said:
Michael Slade
Untitled
Yeah, it'd be a bad day when watching a shuttle launch and as the rockets ignite you look over and see the word 'Enterprise' painted on the side of it.
Scott Brady
Founder
Why do these discussions have to always deteriorate into name calling and schoolyard banter?
We will just delete any obviously personal attacks.
We will just delete any obviously personal attacks.
Antichrist
Expedition Leader
Here's a user of castor correcting swivel balls in the UK where they are even more strict with what's allowed on the road.
BTW, it passed MOT.
BTW, it passed MOT.