Handling issues on uneven roads
Thread Starter
Heel & Toe
Joined: May 2018
Posts: 24
Likes: 1
From: Wiarton Ontario
Handling issues on uneven roads
Hello All
I have been experiencing some handling issues on some of the local roads that are less than smooth. The roads in question are tar and chip and i find my 79 darts and bolts let or right depending on the road. The car handles fine on regular highways. It has the 25560R15 tires and I wondered if the wide tire tends to follow imperfections in the road surface.I'm thinking, and hoping, that a wheel alignment will correct the problem. Is the anything special about aligning the corvette or is it something any decent alignment shop can handle. Any advantage in have a GM dealer do the alignment.
Thanks in advance
Jim
I have been experiencing some handling issues on some of the local roads that are less than smooth. The roads in question are tar and chip and i find my 79 darts and bolts let or right depending on the road. The car handles fine on regular highways. It has the 25560R15 tires and I wondered if the wide tire tends to follow imperfections in the road surface.I'm thinking, and hoping, that a wheel alignment will correct the problem. Is the anything special about aligning the corvette or is it something any decent alignment shop can handle. Any advantage in have a GM dealer do the alignment.
Thanks in advance
Jim
Racer
Joined: Sep 2011
Posts: 414
Likes: 55
From: Humboldt county Ca
Alignment will probably help. Try to find someone who is familiar with c3 vettes. Front end shims like any car but rear end needs corvette specific shims for the trailing arms. I run the same tire and don't have trouble with wandering. I do run a Borgeson box and my front end has about 4° positive castor.
Good luck!
Good luck!
Had a 1976 L-82, 4-sp
Joined: Mar 2011
Posts: 5,338
Likes: 1,213
From: Some days your the dog and some days your the hydrant.
Royal Canadian Navy
You probably have worn suspension parts. The alignment shop won't do an alignment if parts are worn. Alignments aren't hard to do on C3's but the rear is a bit more labour intensive for doing the toe and a lot more labour intensive if the trailing arm bushings need replacement. If you can do your own work you can save a lot of $$$ on labour. There is no advantage to getting it done at a GM dealer.
Last edited by resdoggie; May 30, 2018 at 09:10 AM.
Race Director
Joined: Sep 2004
Posts: 11,874
Likes: 263
From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
rear suspension issues especially shot half shafts mushroom ends really screwed with me like that....Also how is the drag link is it worn?
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,810
From: Cool Northern Michigan
You might as well figure all eight bushings on the control arms are shot, as are the ball joints and likely the idler arm are still original. Which means rotted rubber, sloppy tolerances and too much play in the wheel.
Le Mans Master
Joined: Oct 2007
Posts: 7,455
Likes: 977
From: RI, Now Franklin/Nashville TN
The C3 front end is standard GM design used on other GM cars...just need to make sure you do not any worn components.
The rear is more complicated and unique to GM cars in that the half shafts/ujoints are a part of the 4 link rear suspension and if worn will cause rear steering.In addition, the strut rods control camber and worn bushings will induce rear steer AND the trailing arm bushings if worn will cause havoc, not to mention worn rear wheel bearings. There is much in the rear that can upset the handling if the components are not in tip top shape....
The rear is more complicated and unique to GM cars in that the half shafts/ujoints are a part of the 4 link rear suspension and if worn will cause rear steering.In addition, the strut rods control camber and worn bushings will induce rear steer AND the trailing arm bushings if worn will cause havoc, not to mention worn rear wheel bearings. There is much in the rear that can upset the handling if the components are not in tip top shape....
Last edited by jb78L-82; May 30, 2018 at 04:20 PM.
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Verdad Gallardo
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From: California
Can you tell if it is front or back? Or both?
Is it pulling to one side or the other, when it does this?
I actually would recommend getting the base line settings for your current toe, castor and camber, before you adjust anything!
If you are in the good spec range, and it is still ill handling, then alignment to those same general specs aint going to get you anywhere, except more of the same.
If you change all kinds of stuff new, and then are still in the same spec range, you might still have the same problem.
Generally it is wise to stretch out the castor a little more, the wider your tires get. Also matched camber is important. As if one tire is riding more up on edge, vice the other tire, then that could lead to what you describe.
For toe, I personally for street operation, recommend what is best for the way you drive. Some guys like a lot of self straightening toe, coming out of a turn to a straight-away. Sometimes the spin back or recovery can be too quick. My style is to turn it in and then turn it back out of the turns, but that isn't generally recommended or within the street specs by any alignment recommendations. The manufacturers generally set toe, so the steering comes back automatically to straight. If you have too much toe, then the front tires can be crapping somewhat, and that is why the very narrow range of toe recommendations (1/16-3/16 lets say). Once you get out to say 1/4, then you are going to be wearing out your tires, and crabbing some and the steering will self center faster than you really like, unless you love hands off wheel return spinning. Thus excessive too can cause ill handling. If one tire is too toed, then they are trying to go in direct directions. Therefore to check toe, I recommend a turn to the left and then straighten to see how the recovery is in both directions, to know that you have equal setting, without fancy instruments and gauges.
Thus what we are looking for, by getting the current baseline alignment is a judgment on equality side by side, and whether you have an excessive or incorrect alignment on one or more tires. And the alignment could be affected too, as one member said above, by some bad components. Too much deflection, or the ball joints are shot.
I do think you do have some worn components, just because of your describing good handling in general freeway driving, and ill elsewhere. If the castor, camber or toe was totally bad, you would be getting symptoms also on the highway. Worn components are never as apparent on smooth and straight roads.
And the guy ahead of me, mentioned tire pressure, before I could recommend checking that!
Is it pulling to one side or the other, when it does this?
I actually would recommend getting the base line settings for your current toe, castor and camber, before you adjust anything!
If you are in the good spec range, and it is still ill handling, then alignment to those same general specs aint going to get you anywhere, except more of the same.
If you change all kinds of stuff new, and then are still in the same spec range, you might still have the same problem.
Generally it is wise to stretch out the castor a little more, the wider your tires get. Also matched camber is important. As if one tire is riding more up on edge, vice the other tire, then that could lead to what you describe.
For toe, I personally for street operation, recommend what is best for the way you drive. Some guys like a lot of self straightening toe, coming out of a turn to a straight-away. Sometimes the spin back or recovery can be too quick. My style is to turn it in and then turn it back out of the turns, but that isn't generally recommended or within the street specs by any alignment recommendations. The manufacturers generally set toe, so the steering comes back automatically to straight. If you have too much toe, then the front tires can be crapping somewhat, and that is why the very narrow range of toe recommendations (1/16-3/16 lets say). Once you get out to say 1/4, then you are going to be wearing out your tires, and crabbing some and the steering will self center faster than you really like, unless you love hands off wheel return spinning. Thus excessive too can cause ill handling. If one tire is too toed, then they are trying to go in direct directions. Therefore to check toe, I recommend a turn to the left and then straighten to see how the recovery is in both directions, to know that you have equal setting, without fancy instruments and gauges.
Thus what we are looking for, by getting the current baseline alignment is a judgment on equality side by side, and whether you have an excessive or incorrect alignment on one or more tires. And the alignment could be affected too, as one member said above, by some bad components. Too much deflection, or the ball joints are shot.
I do think you do have some worn components, just because of your describing good handling in general freeway driving, and ill elsewhere. If the castor, camber or toe was totally bad, you would be getting symptoms also on the highway. Worn components are never as apparent on smooth and straight roads.
And the guy ahead of me, mentioned tire pressure, before I could recommend checking that!
Last edited by TCracingCA; May 30, 2018 at 05:05 PM.
Race Director
Joined: Sep 2004
Posts: 11,874
Likes: 263
From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
get your car up and go to the back...pull on the rear wheel at 3 and 9, and 6 and 12, and in and out....
the goal is no movement....if it comes in and out then that's one of the causes of dartiness
the goal is no movement....if it comes in and out then that's one of the causes of dartiness
Last edited by bobs77vet; May 31, 2018 at 09:09 AM.
Thread Starter
Heel & Toe
Joined: May 2018
Posts: 24
Likes: 1
From: Wiarton Ontario
You probably have worn suspension parts. The alignment shop won't do an alignment if parts are worn. Alignments aren't hard to do on C3's but the rear is a bit more labour intensive for doing the toe and a lot more labour intensive if the trailing arm bushings need replacement. If you can do your own work you can save a lot of $$$ on labour. There is no advantage to getting it done at a GM dealer.
Thread Starter
Heel & Toe
Joined: May 2018
Posts: 24
Likes: 1
From: Wiarton Ontario
Thread Starter
Heel & Toe
Joined: May 2018
Posts: 24
Likes: 1
From: Wiarton Ontario
Thread Starter
Heel & Toe
Joined: May 2018
Posts: 24
Likes: 1
From: Wiarton Ontario
Can you tell if it is front or back? Or both?
Is it pulling to one side or the other, when it does this?
I actually would recommend getting the base line settings for your current toe, castor and camber, before you adjust anything!
If you are in the good spec range, and it is still ill handling, then alignment to those same general specs aint going to get you anywhere, except more of the same.
If you change all kinds of stuff new, and then are still in the same spec range, you might still have the same problem.
Generally it is wise to stretch out the castor a little more, the wider your tires get. Also matched camber is important. As if one tire is riding more up on edge, vice the other tire, then that could lead to what you describe.
For toe, I personally for street operation, recommend what is best for the way you drive. Some guys like a lot of self straightening toe, coming out of a turn to a straight-away. Sometimes the spin back or recovery can be too quick. My style is to turn it in and then turn it back out of the turns, but that isn't generally recommended or within the street specs by any alignment recommendations. The manufacturers generally set toe, so the steering comes back automatically to straight. If you have too much toe, then the front tires can be crapping somewhat, and that is why the very narrow range of toe recommendations (1/16-3/16 lets say). Once you get out to say 1/4, then you are going to be wearing out your tires, and crabbing some and the steering will self center faster than you really like, unless you love hands off wheel return spinning. Thus excessive too can cause ill handling. If one tire is too toed, then they are trying to go in direct directions. Therefore to check toe, I recommend a turn to the left and then straighten to see how the recovery is in both directions, to know that you have equal setting, without fancy instruments and gauges.
Thus what we are looking for, by getting the current baseline alignment is a judgment on equality side by side, and whether you have an excessive or incorrect alignment on one or more tires. And the alignment could be affected too, as one member said above, by some bad components. Too much deflection, or the ball joints are shot.
I do think you do have some worn components, just because of your describing good handling in general freeway driving, and ill elsewhere. If the castor, camber or toe was totally bad, you would be getting symptoms also on the highway. Worn components are never as apparent on smooth and straight roads.
And the guy ahead of me, mentioned tire pressure, before I could recommend checking that!
Is it pulling to one side or the other, when it does this?
I actually would recommend getting the base line settings for your current toe, castor and camber, before you adjust anything!
If you are in the good spec range, and it is still ill handling, then alignment to those same general specs aint going to get you anywhere, except more of the same.
If you change all kinds of stuff new, and then are still in the same spec range, you might still have the same problem.
Generally it is wise to stretch out the castor a little more, the wider your tires get. Also matched camber is important. As if one tire is riding more up on edge, vice the other tire, then that could lead to what you describe.
For toe, I personally for street operation, recommend what is best for the way you drive. Some guys like a lot of self straightening toe, coming out of a turn to a straight-away. Sometimes the spin back or recovery can be too quick. My style is to turn it in and then turn it back out of the turns, but that isn't generally recommended or within the street specs by any alignment recommendations. The manufacturers generally set toe, so the steering comes back automatically to straight. If you have too much toe, then the front tires can be crapping somewhat, and that is why the very narrow range of toe recommendations (1/16-3/16 lets say). Once you get out to say 1/4, then you are going to be wearing out your tires, and crabbing some and the steering will self center faster than you really like, unless you love hands off wheel return spinning. Thus excessive too can cause ill handling. If one tire is too toed, then they are trying to go in direct directions. Therefore to check toe, I recommend a turn to the left and then straighten to see how the recovery is in both directions, to know that you have equal setting, without fancy instruments and gauges.
Thus what we are looking for, by getting the current baseline alignment is a judgment on equality side by side, and whether you have an excessive or incorrect alignment on one or more tires. And the alignment could be affected too, as one member said above, by some bad components. Too much deflection, or the ball joints are shot.
I do think you do have some worn components, just because of your describing good handling in general freeway driving, and ill elsewhere. If the castor, camber or toe was totally bad, you would be getting symptoms also on the highway. Worn components are never as apparent on smooth and straight roads.
And the guy ahead of me, mentioned tire pressure, before I could recommend checking that!
Thread Starter
Heel & Toe
Joined: May 2018
Posts: 24
Likes: 1
From: Wiarton Ontario
Thread Starter
Heel & Toe
Joined: May 2018
Posts: 24
Likes: 1
From: Wiarton Ontario
Thanks for all the input guys. I will check all the obvious and not so obvious. Being a first time vette owner I didn't know what to expect in he handling department but I knew that it should be better than it is.The car is an original 89,000 kilometre garage queen that I bought from the original owner. He did maintain the vehicle pretty well over the last 39 years and had just replaced the rear spring when i bought it. I will follow everyones suggestions and see what I find. If I don't find anything obvious, I will go for a good 4 wheel alignment. I will keep you posted on my findings.
jim
jim
Le Mans Master
Joined: Nov 2016
Posts: 9,263
Likes: 951
From: Lake Tahoe, CA
Hello All
I have been experiencing some handling issues on some of the local roads that are less than smooth. The roads in question are tar and chip and i find my 79 darts and bolts let or right depending on the road. The car handles fine on regular highways. It has the 25560R15 tires and I wondered if the wide tire tends to follow imperfections in the road surface.I'm thinking, and hoping, that a wheel alignment will correct the problem. Is the anything special about aligning the corvette or is it something any decent alignment shop can handle. Any advantage in have a GM dealer do the alignment.
Thanks in advance
Jim
I have been experiencing some handling issues on some of the local roads that are less than smooth. The roads in question are tar and chip and i find my 79 darts and bolts let or right depending on the road. The car handles fine on regular highways. It has the 25560R15 tires and I wondered if the wide tire tends to follow imperfections in the road surface.I'm thinking, and hoping, that a wheel alignment will correct the problem. Is the anything special about aligning the corvette or is it something any decent alignment shop can handle. Any advantage in have a GM dealer do the alignment.
Thanks in advance
Jim
https://tech.corvettecentral.com/201...ignment-specs/
Thread Starter
Heel & Toe
Joined: May 2018
Posts: 24
Likes: 1
From: Wiarton Ontario
