Wandering c3 Vette
Thread Starter
Intermediate
Joined: Aug 2009
Posts: 45
Likes: 0
Wandering c3 Vette
Hi I have a 1979 corvette and I restored most everything.. I take it out for the first drive after the alignment and it is all over the road.. It wonders left and right and when I accelerate it feels like the rear end is shifting out a bit and it pulls left.. Also when I hit a bump in the road the car feels like it wants to take off to the right after the bump.. Does anyone have any ideas?? I have checked all suspension in the car and tightened it and made sure there was no worn parts also put all new ball joints in and swaybar links.. I am almost thinking of selling it because it drives horrible.. I really like this car but hate the way it drives.. What do I do??? 
Burning Brakes
Joined: May 2009
Posts: 1,232
Likes: 6
From: Tucson AZ
St. Jude Donor '12
First thought, didn't the alignment shop TEST DRIVE the car? Take it back and put a supervisor in the driver's seat and go for a spin.
Its quite possible that much of the issue is related to the tires. However camber and toe in can contribute. Let us know what they say at the shop.
Its quite possible that much of the issue is related to the tires. However camber and toe in can contribute. Let us know what they say at the shop.
Melting Slicks
Joined: May 2005
Posts: 2,486
Likes: 71
From: Elkhart Lake, Wisconsin
Not enough positive caster will also cause darting, more positive caster will reduce it.
http://www.ozebiz.com.au/racetech/theory/align.html
Most shops don't deal with bump steer, but that might be your issue after a bump.
http://www.bakerprecision.com/longacr17a.htm
I slotted my upper control arm cross shafts to get more caster, and the aftermarket control arms are designed for more adjustment as that has been a common complaint.
Another forum member 69restomod had some similar issues after he finished his car and he took it back to the alignment shop had them put more caster in and he said it helped the wandering a lot. He has VBP control arms and the shop had adjusted to the factory settings initially.
If you have all new joints etc, it should be able to be improved. I agree take it back to the alignment shop and have them drive it.
http://www.ozebiz.com.au/racetech/theory/align.html
Most shops don't deal with bump steer, but that might be your issue after a bump.
http://www.bakerprecision.com/longacr17a.htm
I slotted my upper control arm cross shafts to get more caster, and the aftermarket control arms are designed for more adjustment as that has been a common complaint.
Another forum member 69restomod had some similar issues after he finished his car and he took it back to the alignment shop had them put more caster in and he said it helped the wandering a lot. He has VBP control arms and the shop had adjusted to the factory settings initially.
If you have all new joints etc, it should be able to be improved. I agree take it back to the alignment shop and have them drive it.
Last edited by RobRace10; Aug 19, 2009 at 11:59 AM.
Melting Slicks
Joined: May 2005
Posts: 2,486
Likes: 71
From: Elkhart Lake, Wisconsin
1979 Corvette Alignment Specs
front
camber 0.75* +/- 0.75*
caster 2.25* +/- 1.00*
total toe 0.50* +/- 0.2*
rear
camber -0.50* +/- 0.50*
total toe 0.19* +/- 0.06*
------------------------------
Last edited by RobRace10; Aug 19, 2009 at 12:12 PM.
Thread Starter
Intermediate
Joined: Aug 2009
Posts: 45
Likes: 0
Yes it should be somewhat negative in my opinion but this is what I found for the 79 factory spec which looks like .075 positive. I would max out caster and run some negative camber.
1979 Corvette Alignment Specs
front
camber 0.75* +/- 0.75*
caster 2.25* +/- 1.00*
total toe 0.50* +/- 0.2*
rear
camber -0.50* +/- 0.50*
total toe 0.19* +/- 0.06*
------------------------------
1979 Corvette Alignment Specs
front
camber 0.75* +/- 0.75*
caster 2.25* +/- 1.00*
total toe 0.50* +/- 0.2*
rear
camber -0.50* +/- 0.50*
total toe 0.19* +/- 0.06*
------------------------------
Last edited by switzerhenry; Aug 19, 2009 at 01:00 PM.
Safety Car
Joined: Apr 2000
Posts: 3,802
Likes: 61
From: Wichita KS
Did you replace your shocks? I had darting problems with my big block until I got new ones.
The other thing I had to do was tighten the steering column at the steering box because it was too loose. You could move the steering wheel and not the wheels.
cc
The other thing I had to do was tighten the steering column at the steering box because it was too loose. You could move the steering wheel and not the wheels.
cc
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Melting Slicks
Joined: May 2005
Posts: 2,486
Likes: 71
From: Elkhart Lake, Wisconsin
Yes Positive Caster. I think if you do some searches but you should be able to get 3.5 with the stock setup. With the slotted crosshaft it is easy to get 5 degrees.
Some more info from Corvettesteering.com:
http://www.corvettesteering.com/Front%20end%20specs.htm
also this thread may help:
http://forums.corvetteforum.com/c3-t...sensitive.html
and a thread on modified and offset cross shafts:
http://forums.corvetteforum.com/c3-t...ss-shafts.html
Some more info from Corvettesteering.com:
http://www.corvettesteering.com/Front%20end%20specs.htm
also this thread may help:
http://forums.corvetteforum.com/c3-t...sensitive.html
and a thread on modified and offset cross shafts:
http://forums.corvetteforum.com/c3-t...ss-shafts.html
Last edited by RobRace10; Aug 19, 2009 at 05:26 PM.
Safety Car
Joined: Apr 2000
Posts: 3,802
Likes: 61
From: Wichita KS
There is an adjustment bolt on the top of the steering box with a jamb nut on it. Loosen the jamb nut while holding the bolt in place, then turn the bolt clockwise slightly, like maybe 1/4 turn to start with, tighten the jamb nut and test drive to see if the steering wheel sloppiness improves. If it does keep doing that until the slop is gone. If it gets worse, go the other direction. It is unlikely you will need to turn it counterclockwise.
I have been told not to turn more than 1.5-2 turns total.
cc
I have been told not to turn more than 1.5-2 turns total.
cc
Le Mans Master
Joined: Oct 2007
Posts: 7,451
Likes: 974
From: RI, Now Franklin/Nashville TN
My experience is that C3's can be darty with all OEM suspension components, especially the gymkhana/sport suspended cars. All good points above especially about shocks and suspension alignment. I found on my car that the shocks, rear spring type (use a composite not steel), along with competition strut rods with the heim joints in the rear, as well as the tires will do most to eliminate what you are describing. I also replaced my upper and lower control arm bushings in the front with poly and that made a great difference, although new rubber ones would probably have helped a great deal as well.
Safety Car
Joined: Apr 2000
Posts: 3,802
Likes: 61
From: Wichita KS
cc
Burning Brakes
Joined: May 2009
Posts: 1,232
Likes: 6
From: Tucson AZ
St. Jude Donor '12
Be very careful adjusting the nut on the steering gearbox. Done improperly the gearbox can easily become damaged. This is one of two adjustments on the gearbox. In my experience, this has never solved the bumpsteer and tramlining conditions you are describing.
Given fresh ball joints, a arm bushes, and tie rod ends, generally those conditions are addressed most effectively by (in order of effectiveness):
Given fresh ball joints, a arm bushes, and tie rod ends, generally those conditions are addressed most effectively by (in order of effectiveness):
- changing to different tires (usually a bit narrower, not always)
- increasing the toe-in
- increasing the camber
Drifting
Joined: Jul 2008
Posts: 1,873
Likes: 27
From: Sonora CA
Do not adjust too much, too often (the steering gear) I had a steering gear lock up during a hard turn once. My 73 L48 was acting just like yours, really scary at 60mph and up.
Relpaced everything under the front end and now it's VERY comfy, even at 80 /90 mph. I also adjusted the steering gear, but only in 1/8 turn increments and then only after driving it for about a month each time between adjustments. Also new shocks on the back and a complete alignment too. My wife says it handles better than her Toyota!
Relpaced everything under the front end and now it's VERY comfy, even at 80 /90 mph. I also adjusted the steering gear, but only in 1/8 turn increments and then only after driving it for about a month each time between adjustments. Also new shocks on the back and a complete alignment too. My wife says it handles better than her Toyota!
Race Director
Joined: Jan 2003
Posts: 18,341
Likes: 101
Rear trailing arms?
Bushings?
People often overlook the back of the car when thinking about problems like this.
You wouldn't be the first person who replaced and aligned everything up front ....... and then found the real problem was in the idea that it was the back wheels that were all over the place.
Replaced both arms completely just so we wouldn't have to deal with this again but when the bushings in the front of your trailing arms go bad like mine were.......the car drives EXACTLY like what you are describing.
Vette Brake offered a pretty good deal on complete rebuilds with new wheel bearings included. Steep core charge so be sure to send the old ones back to 'em though.
Bushings?
People often overlook the back of the car when thinking about problems like this.
You wouldn't be the first person who replaced and aligned everything up front ....... and then found the real problem was in the idea that it was the back wheels that were all over the place.
Replaced both arms completely just so we wouldn't have to deal with this again but when the bushings in the front of your trailing arms go bad like mine were.......the car drives EXACTLY like what you are describing.
Vette Brake offered a pretty good deal on complete rebuilds with new wheel bearings included. Steep core charge so be sure to send the old ones back to 'em though.