Re: Alignment specs
Don W. said:
I would beg to differ.
Dave, If you mean shimmy and if alignment is off at those speeds, especially if castor and/or camber is different side to side or if toe is not correct you could be ending up with -0- to maybe some toe out at those speeds which would not be good.
But first I would check balance and trueness of the front wheels. Just an off the wall thought do you have the same offset wheels on both sides?
FYI My truck with the sportmachine specs handles much better. Speed at the end of the 1/4 is 98-99 with no tire shake.
Don I wont argue with yeah, everyone has their opinion on this stuff. I'll just put down my input
I've been aligning vehicals for years, ( actually done the work myself, with multiple different alignment machines, almost every make and model of the planet. )
If caster is out enough it's causing a shake, the truck would pull sooo hard to one side or the other you would never get it to a 100 mph. I drove a 4wd S10 pickup, same running gear as a Sy, that had a 6* caster split, besides pulling right super hard, no shake.
Exactly the same for camber, it would have to be sooo bad that the vehical would pull sooo hard you couldn't drive it and it would eat the tires.
If toe was out that bad, which were not talking a .10 of a degree, it would be multiple degree's you would hear the tires just screaming as they're dragged down the road sideways. Everytime I lift or lower a truck, you hear the tires howling just driving it around the shop to the alignment pit and you'd never get it to a 100 mph.
ALIGNMENT will NEVER cause a shake :tup:
LIL QIK said:
Well....again guys....not talking about a shake....I'm talking about a literal speed wobble....I'm talking about the ass end of the truck damn near getting a fish tailing effect. The kind of thing where if I don't let out of it....I could see the body roll getting so bad that I could lose control of the truck.
But to answer your question.....I'm running the same offset on both sides and the tire balance has been checked again and again.
Now my brother who does the alignments at his shop has suggested that the caster might be an issue which is why he did some research and found some other numbers other than what's programmed in his machine for the Typhoon. But I wanted to see if your alignment change helped or not before I go try a different setting.
Thanks for the help though......
Dave
OK so were talking about the rear of the truck, another reason it isn't the alignment, since there's no adjustment there from the factory.
Is the truck lowered?? Double check the U-bols aren't loose?? Has the axle shifted?? Bad or broken leaf spring??
Very curious why your brother would think caster is an issue?? Maybe you could ask him to explain. Not that he doesn't know what he's talking about, I just would like to see his logic in coming to that conclusion, he's seen the truck, I haven't. How could the caster casue the rear to shake?? Unless he means the rear axle is shifted?
Don W. said:
Hmmm, is he checking rear alignment as well? I suspect he is. So the rear is fishtailing? I interpreted your comments as a front shimmy. Oh well.
I wonder if an out-of-phase wheel hop is occurring. While one is up the other is down sort of thing. I'm thinking this could be caused by a bad tire. It balances OK on the machine but at those speeds it starts loosing its concentricity(sp?) In other words it's not round anymore.
Just a thought.
You have to check the rear alignment, as hard as it is for most people to believe or understand the rear of a vehical is what steers it. The front it set up to whatever the rear is at.
If it's a bad tire it will start shaking long before a 100 mph. The harmonics of a out-of-balance tire or not round tire seem to start to take effect at about 40-50 mph+. They can come and go also, like shake at 40mph, smooth at 70mph, shake again at 100mph. If it's shaking at high speed it should shake at a lower speed first.
Also anyone with atleast one day experience with a tire balancer could see if it was out of round immediately.
Rear fishtailing, I would go over everything back there very carefully, but it's really hard to guess at would could make it shake at only super high speeds. :2cents:
