flyingaces Posted May 15, 2008 Report Share Posted May 15, 2008 I have a front end shake( the wheels look like basket balls bouncing up n down, and the steering wheel looks like a helicopter taking off) on a car and i can't seem to figure it out... It seems to do it only when the car has not been ran for a good while, after a few laps it seems to go away???? the steering linkage is almost new, and there is no slop or play in anything. i have checked for bent wheels and steering components and have found nothing. The car has power steering, and i plan to remove the belt to see but other than that i am stumped.. any ideas??????????? Link to comment Share on other sites More sharing options...
abrungot Posted May 15, 2008 Report Share Posted May 15, 2008 More info needed? When does it shake, On corner entry, Stright away, Center of corner, All the time? Link to comment Share on other sites More sharing options...
Truck99 Posted May 15, 2008 Report Share Posted May 15, 2008 I've noticed b-rocket's 29 car doing that every now and then. It did it in a former life also. I wonder if something in the geometry is making it go from toe-out to zero toe and then maybe into toe-in when the wheels are turned. As it approaches zero toe, the wobble begins. How much caster is in the car, and have you measured caster gain (or loss?) Could be someting similar going on with caster as what I talked about with toe. Link to comment Share on other sites More sharing options...
NickHolt Posted May 15, 2008 Report Share Posted May 15, 2008 A few thoughts. 1) Make sure you run at least a little static toe out. Race cars don't like zero toe. 2) Run some positive caster on both sides. More on the RF than the LF. Don't use negative caster on the LF because the wheel will try to turn around and point in the wrong direction with LF negaive caster. 3) Check your front shocks on a dyno. Sometimes a wheel hop is induced by a shock that has given up or is way too soft on both compression and rebound. 4) Don't spring too stiff on the RF and LR. If you do, the car tends to teeter-totter (a very complex suspension engineering term) on the RF and LR which leaves very little (maybe even zero) weight on the LF. When the LF carries no weight, it is free to do just about anything it wants to. Nick Link to comment Share on other sites More sharing options...
trlrider Posted May 15, 2008 Report Share Posted May 15, 2008 It seems to do it only when the car has not been ran for a good while, after a few laps it seems to go away???? the steering linkage is almost new, and there is no slop or play in anything. Sounds like the shocks have gone bad and the valves are sticking closed after the car has sat for some time! After a couple of laps around the track and the fluid warms up, the valves unstick and the problem goes away! Have also seen the same issue with shocks mounted upside down! After a few laps the shock will hydra-lock and become basically solid, the car will skate all over the place and bounce like crazy! Just thoughts from the old days! Try a different set of shocks on the car! Oh, and all the stuff Nick said! Link to comment Share on other sites More sharing options...
bigfat Posted May 15, 2008 Report Share Posted May 15, 2008 It will only do it at a certain speed or RPM I'd say around 4000 RPM. It does go away after a couple of laps, but sometimes it will reappear during caution laps. We usually have it set up between 1/8 and 1/4 out on the toe. Caster hasn't been checked in quite some time. It also seems to only be the left front from what I have felt in the past and been told, when black flagged off the track for what was thought to be loose lugs, which it isn't. LMAO Charlie, I came to this link to post that very thing. $50,000 on a scratch off ticket. Damnnnnnnnnn. Link to comment Share on other sites More sharing options...
soaker Posted May 15, 2008 Report Share Posted May 15, 2008 Sounds like too much caster split. Link to comment Share on other sites More sharing options...
becka29 Posted May 15, 2008 Report Share Posted May 15, 2008 Could be the power steering. Link to comment Share on other sites More sharing options...
matt5858 Posted May 15, 2008 Report Share Posted May 15, 2008 My super stock did that last year and I found it to be the caster. It would only do it under caution or slower speeds and would go away when i would speed up. I have also heard people say that the gear box could cause the same problem. I would check your caster first. Hope you fix it cause I know how frustrating it is. Matthew Hodge Link to comment Share on other sites More sharing options...
Danielsen Motorsports Posted May 15, 2008 Report Share Posted May 15, 2008 Race before last we experienced the same thing. Servo in the gear box was badly worn, when worn out it places pressure on both left and right, obviously not normal. Basically the gear box is applying pressure when it shouldnt because you have the wheel straight. We changed the gear box, problem solved. Its not the camber caster or some BS RF spring. Link to comment Share on other sites More sharing options...
bigfat Posted May 16, 2008 Report Share Posted May 16, 2008 I'm thinking we can rule out the gear box. It did it all last year. About 2 races to go in the season, I hit the 58 with the left front which snapped the shaft in the gear box, bent the left front spindle and right side tie rod. We changed all that out and it was still doing it. Unless of course the gear box I got from Camo,,,,, I mean Keith Garrett was already worn out. It did come off an old camaro. Link to comment Share on other sites More sharing options...
HiTech Posted May 16, 2008 Report Share Posted May 16, 2008 CHECK BALL JOINTS AND BUSHINGS .. Link to comment Share on other sites More sharing options...
poorboy Posted May 16, 2008 Report Share Posted May 16, 2008 Make sure you have positive caster on both sides. Link to comment Share on other sites More sharing options...
Danielsen Motorsports Posted May 16, 2008 Report Share Posted May 16, 2008 Unless it was a new gear box you cant eliminate it if its an old box. Link to comment Share on other sites More sharing options...
mac70 Posted May 16, 2008 Report Share Posted May 16, 2008 It may not have anything to do with it, but I had one that had water in one of the tires and it did the same thing it actually was coming off the ground. You probably have already checked the tires but I have seen it happen. Link to comment Share on other sites More sharing options...
flyingaces Posted May 16, 2008 Author Report Share Posted May 16, 2008 Thank every one for the respone, i have tried a lot of what has been suggested, and no luck. i just got my hands on a cester camber gauge and will checking that today. I have noticed that with the car idling and slowly turning the wheel back and forth i feel a restriction in the steering wheel. i will also try and change the steering box. Its hard to trouble shoot these things when you have to almost be at the track to test it. THANK EVERY ONE AGAIN FOR YOUR HELP Link to comment Share on other sites More sharing options...
CNC93 Posted May 16, 2008 Report Share Posted May 16, 2008 Do you think the driver is shaking so bad that it's tranferring to the front wheels? Link to comment Share on other sites More sharing options...
flyingaces Posted May 16, 2008 Author Report Share Posted May 16, 2008 We have taken that into consideration, and have changed drivers... both complained of it shaking soo bad and they couldn't hold on to there beer Link to comment Share on other sites More sharing options...
RodneyRodriguez Posted May 16, 2008 Report Share Posted May 16, 2008 may need some special tires.... Link to comment Share on other sites More sharing options...
speed demon 7 Posted May 16, 2008 Report Share Posted May 16, 2008 I have the same problem. I was told it is because of the extreme caster we are running. I just thought it was the tires, after they set for a while, it takes a lap or 2 to equalize the balance? But it is a very violent shake, and it doesn't happen all the time. Looniedude I think saw it in my car in hot laps one race this season and said something about it. Link to comment Share on other sites More sharing options...
flyingaces Posted May 16, 2008 Author Report Share Posted May 16, 2008 YEAP SAME PROBLEM, WHAT IS CONSIDERED TOO MUCH CASTER SPLIT???? Link to comment Share on other sites More sharing options...
KISS_Racing Posted May 16, 2008 Report Share Posted May 16, 2008 Charlie, Have you checked your Henway? Just kidding, my vote is caster. Second would be moisture in the tire, but not likely unless you've aired the tires with a compressor that doesnt have a water-trap. Link to comment Share on other sites More sharing options...
flyingaces Posted May 16, 2008 Author Report Share Posted May 16, 2008 THAT DANG HENWAY WILL GET YOU EVERY TIME, WE WILL GET RIGHT ON THAT ONE Link to comment Share on other sites More sharing options...
KISS_Racing Posted May 16, 2008 Report Share Posted May 16, 2008 good luck.... you looked good out there sat. night! Link to comment Share on other sites More sharing options...
Ford27 Posted May 18, 2008 Report Share Posted May 18, 2008 This may be way off, but make sure your ps box dont have any trapped air and that the lines to the box are not reversed.I actually did that once and had the same symptoms but 10 times worse. the steering wheel would try to spin by itself and the wheels shook so violent it was totally undrivable. just an idea Link to comment Share on other sites More sharing options...
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