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Help Support Hardline Crawlers :
Alignment ?
- Thread starter Brian H
- Start date
Jason C
Well-Known Member
Yeah.......it does.
CrustyJeep
Well-Known Member
Oh well if it's a Jeep it won't matter at all :haha:
But seriously, what's this "no bump steer" thingy you mentioned? Is it running full hydro, or are you just dilusional?
But seriously, what's this "no bump steer" thingy you mentioned? Is it running full hydro, or are you just dilusional?
CrustyJeep said:
The guy that did the spring over pointed the pinion at the transfer case. Everytime he hits a bump it steers for him (Bump Steer) . Im going to fix it for him and a buddy that works at les scrubs says I need to do this and this and this to make it drive right.
CrustyJeep
Well-Known Member
Wait wait wait, why do I get the feeling you're misusing the term "bump steer"? Bump steer has nothing to do with caster...Brian H said:
crash2
-Oh no I picked a side-
Ok... toe is the in/out of your wheels. Caster is the tilt front/rear of your wheels. differnt setups require diffent caster. Like we set our stuff up to 7 degrees where a race car would go different. Caster also helps with return to center. Camber is the tilt side to side of the tire. most vehicles are zero typically. Bump steer is typically caused by the drgalink....
Knok2222
Well-Known Member
ok... well too much negative caster can have EVERYthing to do with bump steer. IF your spindle is got lets say 3* of neg caster then your turning into the ground. Uneven terrain on any kind of road will actually compound the force through the stearing geomatry causing the vehicle to vere all over the road.. Now dont get me wrong,... crash is correct as well. a draglink, or panhard bar that is worn can affect the same way in the fact that it allows lateral movment in the front end.... thats my 2 cents anyway.. brian just likes to argue with me.:flipoff: :flipoff:
CrustyJeep
Well-Known Member
Bump steer is a very specific symptom. It sounds general, but it's not, and it's rather poorly named IMO. It really has nothing to do with "bumps", in the way that many people think of it.
Bump steer is simply the difference between the arc your suspension takes through it's travel versus the end of your steering link, a drag link in most cases for a 4x4. In other words, when your axle moves straight up and down (as with leaf springs), the drag link moves in an arc. This causes the wheels to steer back and forth under suspension travel.
It can get so bad that it actually limits your steering angle under hard flex. With the right wheel drooped, you might not be able to steer all the way to the right. It's a pain when you're trying to negotiate a technical obstical and need full steering.
About the only way to completely eliminate bump steer is with full hydro. A properly setup pan hard bar will also work nicely, although not quite 100%.
This is why you don't see front 4-links without hydro. Bump steer city.
Bump steer is simply the difference between the arc your suspension takes through it's travel versus the end of your steering link, a drag link in most cases for a 4x4. In other words, when your axle moves straight up and down (as with leaf springs), the drag link moves in an arc. This causes the wheels to steer back and forth under suspension travel.
It can get so bad that it actually limits your steering angle under hard flex. With the right wheel drooped, you might not be able to steer all the way to the right. It's a pain when you're trying to negotiate a technical obstical and need full steering.
About the only way to completely eliminate bump steer is with full hydro. A properly setup pan hard bar will also work nicely, although not quite 100%.
This is why you don't see front 4-links without hydro. Bump steer city.
CrustyJeep
Well-Known Member
Caster is important. It helps with your return-to-center and if it's negative I think it can cause, or at least accentuate death wobble. Don't fawk with it. If you want better pinion angle, great, but don't get it at the cost of camber. Cut and rotate your C's. Nobody wants to see you dead in a ditch because your rig got too squirrely at 32 MPH between trails.
Camber I would say is effectively irrelevant for this sport, for a couple reasons. First off, anything even remotely close to zero will work fine. Where as on a street or race car, where a degree can make a huge difference, a degree won't do diddly when your flexed up on a rock at .005 MPH. Uneven tire wear isn't even a consideration on a pure trail rig. Second, you can't change it much anyway on a straight axle. Forget about it :flipoff:
Camber I would say is effectively irrelevant for this sport, for a couple reasons. First off, anything even remotely close to zero will work fine. Where as on a street or race car, where a degree can make a huge difference, a degree won't do diddly when your flexed up on a rock at .005 MPH. Uneven tire wear isn't even a consideration on a pure trail rig. Second, you can't change it much anyway on a straight axle. Forget about it :flipoff:
Knok2222
Well-Known Member
Absolutly correct, but in my shop we have just used that term for this problem. Im not sure if Brian said what the problem was, but going down the freeway, or any road for that matter, and hitting holes is making the jeep steer all over and he is constintly having to over correct. Annoying problem, but Brian will fix it. I still feel that steering geomatry, and alignment are important on any rig. Now the specs might be able to be a little broader on a crawler or strictly offroad vehicle, but the issue should always be addressed.
64FJ40
Well-Known Member
Knok2222 said:
Then quit calling it bumpsteer and call it death wobble. They're vastly different.
CrustyJeep
Well-Known Member
You gotta fix the caster, no question. Sounds dangerous.Brian H said:
How's the drag link angle? Flat at ride height?
Knok2222
Well-Known Member
64FJ40 said:
hmmm.... wouldnt bump steer make a better title for the problem at hand? I dont know who came up with the original deffinition, but he should probably be shot. anyway im not trying to start a piss'n contest, and im not interested in correcting anyones grammer. I got my point across, and you interprated what I was saying so who gives a $hiT.
64FJ40
Well-Known Member
Knok2222 said:
No.
Bump steer refers to the phenomenon wherein (as Crusty described) movement of the axle (such as hitting a bump) causes a movement of the steering linkages (steer) that is independent of the driver's input.
Death wobble results from poor caster (and sometimes other things). If you've ever had death wobble, you understand precisely why it is thusly named.
