After checking every thing twice, and re-alighned with 2.5 deg pos caster I still have a wooble in the front 55 to 70 mph, I even ran my bros aluminum rims with 2556015 tires with the same results, this car has been cked by three different shops and cannot find the problem, I am running 15x8 with 255 60 15 BFG's I was told that I may need up to 4 deg caster to solve this problem, by a couple of x old road racers?

Any one expearance this problem and or would aftermaret upper arms possiblly solve my problem before I #%*&*



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Caster
Positive caster improves straight line tracking because the caster line (the line drawn through the steering pivot when viewed from the side) intersects the ground ahead of the contact patch of the tire. Just like a shopping cart caster, the wheel is forced behind the pivot allowing the vehicle to track in a straight line.

If this is the case, then why did most cars have negative caster specs prior to 1975 ? There are a couple of reasons for this. In those days, people were looking for cars that steered as light as a feather, and cars back then were not equipped with radial tires. Non-radial tires had a tendency to distort at highway speed so that the contact patch moved back past the centerline of the tire (Picture a cartoon car speeding along, the tires are generally drawn as egg-shaped). The contact patch generally moves behind the caster line causing, in effect, a positive caster. This is why, when you put radial tires on this type of car, the car wanders from side to side and no longer tracks straight. To correct this condition, re-adjust the caster to positive and the car should steer like a new car.

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Dont think it's castor, I run 265x50 15 with 2+ castor. You say you ran your brothers rims, with your tires or his tires? When you say wobble do you mean vibration or a repeating thump thump sound? Do you have excessive play in the steering box?

 

Sir, I ran his rims and tires, it's the darndest thing, it's like the so called death wobble experienced by jeeps with large tires, I can run it well past 70mph and it calms to a light vibration, been told could be drive train problems, 5 speed richmond, set pinion angle and balanced drive shaft with new joints same with drive axels. Shifter dosn't shake or rattle, smooth. had tire's force balanced did ok for a little while, then balanced and shaved on the car, did ok for a little while like a week. three alighnment shops none found any issues with suspinsion parts which are not that old, sterring box, installed a new one about 10 yrs age and recently adjusted lash, car doesn't appear to have any adverse handling problems, minimual suspionsion upgrads simular to a street a slalom set up. Set the car on jacks and run it thru the gears, jacks under rear sock mounts I get a very very minor amount of shake, clutch in clutch out no change, costed down hills at 55mph with engine off in nuetral still get the wobble, installed strut bar up front overall improvment but stil get the wobble, pwr sterrin componets all seem to be adjusted with no problems there. located bell housing with dial indicator, used digitol guage for pinion angle, I can rev the enging in nuetral smooth! with clutch in or out smooth.

Thanks for your interest to help ! Mike.

 

Was the car ever in an accident, bent front spindle? Did the problem start after installing the new transmission?

 

Problem started after the car was modified with trans and new suspsion, gota run into a meeting. Thanks

 

what are the details of the new suspension?

 

front 1.25 sway bar,new but monro gas shocks. pwr steering has rebuilt componets, front springs are for SB stock HD sorry no lbs info, step up from stock, rear stock HD 5 leaf w 3/4 sway bar and monros, John Mcgee of Corvette connection set me up w them 10yrs ago, cars been in family since 1971, and I meant to say things started to wobble a couple of yrs after I made any mods, I even bought a new set of 15 X 8 rims and tires second time around thinking the first set was bad, run out about 15 thousand inner and outer front and back, maybe I should go back w/ 70series. I have a shop (TAFA) in Nashville that said they would look into it if I leave with them, they are heavy and light truck suspension, I think they will treat me right as they have seen the car before and love it.

Thanks again, thought I might find someone with simuliar probs that they corrected.

 

Correction 1.125 front sway bar.

On another note my first car was a 1966 Olds Toronado, Lord I wish I still had it !
second was a 1950 chevy delux cab PU, I put a 327, 4 speed, 12 bolt in it, I never expericenced any wobble even with the old original 16'' rims.
3rd was a 70 Olds 442, 455 4 spd W30, I rebuilt the engine x2 tranny once and rear end, still never encountered any thing like the problems I am having?


Rotor run out on all 4 wheels less than 5 thousands just an additional fyi.

Mike