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#1
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Rear suspension issue, I think
Under heavy acceleration with tires spinning in 2nd gear car goes to the left hard enough that I have to let off to maintain control.
67 LeMans Tubular adjustable upper control arms pinion angle set to 2.5-3.0 degrees down Boxed lower control arms with .75' sway bar No Hop bars, 12 bolt posi 3.08's All bushings are rubber and new Measurements taken indicate housing is in proper position for and aft and even from side to side Does anyone know why it is pulling to the left and is there a cure.
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Tim Corcoran |
#2
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Sounds like the wheels are spinning at a different rate.
Is it a locked rear?
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Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs! And he was not talking about 1/8 or 1/4 mile ETs! 1) 1940s 100% silver 4 cup tea server set. Two dry rotted 14 x 10 Micky Thompson slicks. 1) un-mailed in gift coupon from a 1972 box of corn flakes. Two pairs of brown leather flip flops, never seen more then 2 mph. Education is what your left with once you forget things! |
#3
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With no way for suspension adjustments, probably can't?
Might try stiffening the right rear shock compression if you had adjustable shocks?
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John Wallace - johnta1 Pontiac Power RULES !!! www.wallaceracing.com Winner of Top Class at Pontiac Nationals, 2004 Cordova Winner of Quick 16 At Ames 2004 Pontiac Tripower Nats KRE's MR-1 - 1st 5 second Pontiac block ever! "Every man has a right to his own opinion, but no man has a right to be wrong in his facts." "People demand freedom of speech to make up for the freedom of thought which they avoid." – Socrates |
#4
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Its a new Yukon posi unit in a 12 bolt
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Tim Corcoran |
#5
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Are your axle tubes welded to center section? If one let loose a car will want to swap lanes on you per my experience with a 1966 GTO
put jack stands under rear frame and floor jack center section looking at tubes for movement
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If your not at the table you're on the menu A man who falls for everything stands for nothing. Last edited by Formulas; 03-24-2024 at 09:35 PM. |
#6
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I had it up on the lift and measured everything if there was any movement I think I would of found it.
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Tim Corcoran |
#7
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they are fairly rigid even when roset welds are broken but the joint will flex under power then rear wheels dont track truely straight steering the car
supporting the frame and jacking the center punkin will make it visually flex if broken if you say their solid then they are solid
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If your not at the table you're on the menu A man who falls for everything stands for nothing. |
#8
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Your rear end is gona try and rotate under accleration that's probly why your getting rear steer ajustable shocks or ajustable sway bar should help.
GT |
#9
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I do have adjustable upper control arms
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Tim Corcoran |
#10
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Adjustable sway bar?
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Tim Corcoran |
#11
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Funny thing, I put in a rear sway bar and new shocks and it exaggerated the issue.
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Tim Corcoran |
#12
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Without getting yourself killed, do a burnout on the other side of the road to rule out the crown of the road making the rear drift right pushing the car left.
I would say that the passenger wheel is exerting more downward pressure and during spinning it has more force to push the car left. Too much preload on passenger side or suspension binding keeping the passenger tire from traveling up the same amount as the left.
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Mick Batson 1967 original owner Tyro Blue/black top 4-speed HO GTO with all the original parts stored safely away -- 1965 2+2 survivor AC auto -- 1965 Catalina Safari Wagon. |
#13
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Quote:
Is this when doing a burnout?
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John Wallace - johnta1 Pontiac Power RULES !!! www.wallaceracing.com Winner of Top Class at Pontiac Nationals, 2004 Cordova Winner of Quick 16 At Ames 2004 Pontiac Tripower Nats KRE's MR-1 - 1st 5 second Pontiac block ever! "Every man has a right to his own opinion, but no man has a right to be wrong in his facts." "People demand freedom of speech to make up for the freedom of thought which they avoid." – Socrates |
#14
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Put an LS on it!
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#15
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On hard acceleration, the pinion is trying to "climb" up the ring gear which reduces the effective weight on the passenger side tire. (Which is why an open differential usually only spins the passenger side tire) As a result, the driver side tire experiences a higher coefficient of friction, compressing the control arm bushings on that side and inducing a rear wheel steering effect that makes the vehicle want to go left. You might try running a few pounds more pounds of air pressure in the left tire to reduce the contact patch slightly to even out the tractive effort between the two sides.
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#16
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Yes, tires spinning = burnout
I hammer it from a dead stop tires spinning shifts into 2nd tires still spinning car goes left pretty hard can't correct it and I let off.
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Tim Corcoran |
#17
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Tim Corcoran |
#18
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#19
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I wouldn't worry about suspension if it's from a burnout.
Need to know how it's done. Rolling burnout? Linelock? Have a trough to start burnout? Back into water? I also wouldn't start in 1st gear for burnout. (or 2nd really) Then worry about same circumference tires, front to rear tires inline with each other, brakes hanging up on one side or other, so many things.
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John Wallace - johnta1 Pontiac Power RULES !!! www.wallaceracing.com Winner of Top Class at Pontiac Nationals, 2004 Cordova Winner of Quick 16 At Ames 2004 Pontiac Tripower Nats KRE's MR-1 - 1st 5 second Pontiac block ever! "Every man has a right to his own opinion, but no man has a right to be wrong in his facts." "People demand freedom of speech to make up for the freedom of thought which they avoid." – Socrates |
#20
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When I was a youngster many years ago my dad had a 67 Oldsmobile Delmont 88 with a 425 and a two barrel. That thing would do a burnout for ever until you let off and it went straight as an arrow and this was with a non posi rear. My car has bigger tires, posi and more power but I still can't figure out why the aggressive turn to the left. I will put it up on the lift tomorrow and jack up the pumpkin just to see if there is any movement.
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Tim Corcoran |
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