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Author Topic:   Front end shimmy
driver27
Dirt Full Roller

Total posts: 40
posted March 20, 2002 08:21 AM
Ive had a problem develop the last couple races that I cannot find. When idling around the track under a caution, I get a violent front end shimmy that will not go away until i gas up and get some speed. Have checked all of the front steering and everything is good. I also have about +2 dgrees of caster in the left front as I heard 0 caster would do this. At this point im suspecting that the power steering pump may be causing this as it does not seem to be providing alot of assist. Anyone ever ran into this problem? Would like to get some advice before I spring for a new pump maybe unnecessarily. Thanks For the help.

Van

KK17
Dirt Maniac

Total posts: 144
posted March 20, 2002 09:11 AM
what about camber and toe?...sprint car front ends shimmy when not up to speed but that is because a lot of caster and camber are built into the axle making hard to control when idling...I would recheck all front end settings especially the toe..

driver27
Dirt Full Roller

Total posts: 40
posted March 20, 2002 09:16 AM
I have about 3 degrees of caster split in the front end, toe is Out 3/16 inch and camber is +1.5 degrees on the left and -3 degrees on the right. These settings get checked every week.

Thanks Van

race8k
Dirt Forum Racer

Total posts: 98
posted March 20, 2002 10:25 AM
Change the steering sector if there is no slack in any of the steering links.Had this happen on a street stock.Sector seemed fine but when I changed it problem went away.

crash1x
Dirt Roller

Total posts: 10
posted March 26, 2002 12:17 PM
I had this happen a few years back in a hobby
stock. It is from caster split.I replaced every thing in the front end before I found
out.It wont hurt anything to leave it like it is.It takes things to get just right(or wrong)for it to happen.Or you can take some split out.

dkandy94
Dirt Roller

Total posts: 25
posted March 26, 2002 09:01 PM
if you are running a remote canister for the p\s pump, while the engine is running, open the cap & look inside to see how much fluid is being pumped. If you are running a steering quickner, disconnect the steering shaft from the sector & turn the wheel. If you feel a bind, inspect the quickner and ant u joints that are in the shaft. A 3 degree split in caster won't make the wheel shake. check to see if the tires are badly out of round. Also check the run out on the front wheels. All of these things can give you a shimmy at low speed. Hope this helps you!!

crash1x
Dirt Roller

Total posts: 10
posted March 27, 2002 12:08 PM
It is not as much the split as it is an effect of pos. caster. the split and a few other things at the same time make this happen. This is the same thing you see on a sprint car front end and on a shopping buggy
I have done front end work for a living for 15 years and have also seen this on street cars and trucks with as little as 1.5 split
when hitting bumps.But I am sure somebody will say that I am wrong but try adjusting
the front end before you spend $$$ it is free

Donnie Ross
Dirt Full Roller

Total posts: 63
posted March 31, 2002 08:34 PM
this got me one time forgot to check ball joint nut lower was loose exact same problem
fel6t like the front end was falling off at low speeds fine racing glad i found it before it wrecked me, could also be ball joint worn out, hope this helps

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