Gets 'wobbly' above 110 (4th Gen SS)
10-18-2011, 02:26 PM
#16
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Location: Beaumont, TX
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Re: Gets 'wobbly' above 110 (4th Gen SS)
If you want to lower the car you will want to get the lower control arm relocation brackets.
You do not need the adjustable lower control arms. It is pretty rare for an f body wheel not to be centered within the wheel well, front to back.
You will however need to get the adjustable panhard bar. This will allow you to re-center the axle under the car once you have lowered it. I think there is even a panhard bar relocation bracket that also helps when lowering an f body.
None of this is as important as fixing that tie rod end. If that had broken during your 110 mph wobble run, you would no longer have any worries.
You do not need the adjustable lower control arms. It is pretty rare for an f body wheel not to be centered within the wheel well, front to back.
You will however need to get the adjustable panhard bar. This will allow you to re-center the axle under the car once you have lowered it. I think there is even a panhard bar relocation bracket that also helps when lowering an f body.
None of this is as important as fixing that tie rod end. If that had broken during your 110 mph wobble run, you would no longer have any worries.
10-18-2011, 02:49 PM
#17
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Re: Gets 'wobbly' above 110 (4th Gen SS)
If you want to lower the car you will want to get the lower control arm relocation brackets.
You do not need the adjustable lower control arms. It is pretty rare for an f body wheel not to be centered within the wheel well, front to back.
You will however need to get the adjustable panhard bar. This will allow you to re-center the axle under the car once you have lowered it. I think there is even a panhard bar relocation bracket that also helps when lowering an f body.
None of this is as important as fixing that tie rod end. If that had broken during your 110 mph wobble run, you would no longer have any worries.
You do not need the adjustable lower control arms. It is pretty rare for an f body wheel not to be centered within the wheel well, front to back.
You will however need to get the adjustable panhard bar. This will allow you to re-center the axle under the car once you have lowered it. I think there is even a panhard bar relocation bracket that also helps when lowering an f body.
None of this is as important as fixing that tie rod end. If that had broken during your 110 mph wobble run, you would no longer have any worries.
So tonight I'll put the rod end on it but that one rear tire is showing cords on the inside so it's most likely parked for the season at this point, unless I find a super sweet deal on some 295/30's laying around or on Craigslist. Not holding my breath.
I will go test drive it after I put the rod end on it though, to see for sure that's what was allowing it to wobble.
Now y'all know what to get me for Christmas!!!
10-18-2011, 04:09 PM
#18
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Re: Gets 'wobbly' above 110 (4th Gen SS)
My SS is my favorite to drive as well, but I commute 60 miles round trip every day and want to keep the miles off of it. My friends all make fun of my Accord, but its also an M6 with a 244 horse v6 in it that gets 32 mpg. It definitely doesn't form a line of ladies though! lol
10-21-2011, 11:54 AM
#19
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Re: Gets 'wobbly' above 110 (4th Gen SS)
OK so I've done a couple of things...
1) Replaced the tie rod end.
2) Performed the 'Rack Bearing Preload' adjustment per the GM Service Manual. Essentially this removes any (wear) play from the rack, if I understand it correctly.
These 2 things made a big difference as you might expect regarding the car/steering wanting to follow ruts in the pavement. So at low speeds like up to 40mph it made a huge difference.
However, above 70, still exactly the same. Wobbles. Like a 1973 Winnebago. Which is cool if you're playing with Tonka trucks. But not so much in your Camaro. Video...
[autostream]http://autostream.com/camaroz28/?page_type=firebirdplayerthumbnail&framepage=1931& transactionid=1319216080-174111225159&posted_by=350350_www.camaroz28.com&yo utube_video_id=je-zUSsLzPI[/autostream]
Now first of all, yes I know this is bad for my hatch and I shouldn't do it. It was just this once. Secondly, I know I look like Billy Mays. We covered that extensively in a previous thread here on CZ28. I've made peace with it.
I weigh about 210 if that makes any difference. Seems like I shouldn't be able to rock the car this much but I really don't ever try to do it so I have no frame of reference.
In the olden days (pre-divorce) I would have just said to heck with it and replaced every single suspension component. That's really not in the budget any time soon. Yet it continues to seem more and more like it's just all soft and worn out...
1) Replaced the tie rod end.
2) Performed the 'Rack Bearing Preload' adjustment per the GM Service Manual. Essentially this removes any (wear) play from the rack, if I understand it correctly.
These 2 things made a big difference as you might expect regarding the car/steering wanting to follow ruts in the pavement. So at low speeds like up to 40mph it made a huge difference.
However, above 70, still exactly the same. Wobbles. Like a 1973 Winnebago. Which is cool if you're playing with Tonka trucks. But not so much in your Camaro. Video...
[autostream]http://autostream.com/camaroz28/?page_type=firebirdplayerthumbnail&framepage=1931& transactionid=1319216080-174111225159&posted_by=350350_www.camaroz28.com&yo utube_video_id=je-zUSsLzPI[/autostream]
Now first of all, yes I know this is bad for my hatch and I shouldn't do it. It was just this once. Secondly, I know I look like Billy Mays. We covered that extensively in a previous thread here on CZ28. I've made peace with it.
I weigh about 210 if that makes any difference. Seems like I shouldn't be able to rock the car this much but I really don't ever try to do it so I have no frame of reference.
In the olden days (pre-divorce) I would have just said to heck with it and replaced every single suspension component. That's really not in the budget any time soon. Yet it continues to seem more and more like it's just all soft and worn out...
10-21-2011, 03:00 PM
#20
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Re: Gets 'wobbly' above 110 (4th Gen SS)
Well I know from experience and reading on this site that for whatever reason the SS's love to get squirrely at speed in worn/rutted roads. I think everyone agrees that is the wider tires in the front.
From the video I would have to say that your rear suspension bushings look really soft. Luckily factory rubber bushings are fairly inexpensive and since you have two vehicles you could remove the parts yourself and bring them to a shop to have the old ones pressed out and new ones pressed in.
I’d say it is a combination of the different sized tires/wheels in the front paired with soft rear suspension bushings that is causing your wobble.
From the video I would have to say that your rear suspension bushings look really soft. Luckily factory rubber bushings are fairly inexpensive and since you have two vehicles you could remove the parts yourself and bring them to a shop to have the old ones pressed out and new ones pressed in.
I’d say it is a combination of the different sized tires/wheels in the front paired with soft rear suspension bushings that is causing your wobble.
10-21-2011, 03:20 PM
#21
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Re: Gets 'wobbly' above 110 (4th Gen SS)
Well I know from experience and reading on this site that for whatever reason the SS's love to get squirrely at speed in worn/rutted roads. I think everyone agrees that is the wider tires in the front.
From the video I would have to say that your rear suspension bushings look really soft. Luckily factory rubber bushings are fairly inexpensive and since you have two vehicles you could remove the parts yourself and bring them to a shop to have the old ones pressed out and new ones pressed in.
I’d say it is a combination of the different sized tires/wheels in the front paired with soft rear suspension bushings that is causing your wobble.
From the video I would have to say that your rear suspension bushings look really soft. Luckily factory rubber bushings are fairly inexpensive and since you have two vehicles you could remove the parts yourself and bring them to a shop to have the old ones pressed out and new ones pressed in.
I’d say it is a combination of the different sized tires/wheels in the front paired with soft rear suspension bushings that is causing your wobble.
I wonder if it's more that the rear track of the car is wider than the front now? By a good 2.5".
10-21-2011, 04:03 PM
#22
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Re: Gets 'wobbly' above 110 (4th Gen SS)
In any case, for sure the rear is soft. I'll price stock bushings this weekend and maybe I can do that to get by til I can afford to lower it with new springs and stuff. *sigh*
10-21-2011, 04:06 PM
#23
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Re: Gets 'wobbly' above 110 (4th Gen SS)
The wider track could possibly allow more leverage on soft bushings, causing the rear end to move around more than it would if it were stock.
Stock tires on Z28’s were 245/50/16 which have a tread width of 10.0. They were given to SLP who installed the 275/45/17 with a width of 10.9. The tires you now have 255/40/18 have a tread width of 10.2 which is very close to the stock Z28 width. (All of the width’s were taken from one tire manufacturer, I’m sure they will vary from manufacturer to manufacturer.)
There was a thread a while back with an SS owner complaining of wobbly steering at highway speeds, especially in rutted roads. A complaint that I have with my SS. Several other SS owners chimed in with the same complaint. Someone said that he put SS wheels and tires on his Z28 and it wobbled really bad, he replaced them with his factory Z28 wheels and tires and it never wobbled again. For some reason I cannot find this thread, it was good information. Considering that the tires you now have are closer to factory Z28 width I would say this does not apply to you. Although they are slightly taller and slightly wider than factory spec.
I think your rear suspension bushings are soft, and are allowing the rear end to wobble the entire car. The wider rear track may be magnifying this issue but, new bushings might fix it.
Stock tires on Z28’s were 245/50/16 which have a tread width of 10.0. They were given to SLP who installed the 275/45/17 with a width of 10.9. The tires you now have 255/40/18 have a tread width of 10.2 which is very close to the stock Z28 width. (All of the width’s were taken from one tire manufacturer, I’m sure they will vary from manufacturer to manufacturer.)
There was a thread a while back with an SS owner complaining of wobbly steering at highway speeds, especially in rutted roads. A complaint that I have with my SS. Several other SS owners chimed in with the same complaint. Someone said that he put SS wheels and tires on his Z28 and it wobbled really bad, he replaced them with his factory Z28 wheels and tires and it never wobbled again. For some reason I cannot find this thread, it was good information. Considering that the tires you now have are closer to factory Z28 width I would say this does not apply to you. Although they are slightly taller and slightly wider than factory spec.
I think your rear suspension bushings are soft, and are allowing the rear end to wobble the entire car. The wider rear track may be magnifying this issue but, new bushings might fix it.
10-21-2011, 04:12 PM
#24
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Re: Gets 'wobbly' above 110 (4th Gen SS)
The wider track could possibly allow more leverage on soft bushings, causing the rear end to move around more than it would if it were stock.
Stock tires on Z28’s were 245/50/16 which have a tread width of 10.0. They were given to SLP who installed the 275/45/17 with a width of 10.9. The tires you now have 255/40/18 have a tread width of 10.2 which is very close to the stock Z28 width. (All of the width’s were taken from one tire manufacturer, I’m sure they will vary from manufacturer to manufacturer.)
There was a thread a while back with an SS owner complaining of wobbly steering at highway speeds, especially in rutted roads. A complaint that I have with my SS. Several other SS owners chimed in with the same complaint. Someone said that he put SS wheels and tires on his Z28 and it wobbled really bad, he replaced them with his factory Z28 wheels and tires and it never wobbled again. For some reason I cannot find this thread, it was good information. Considering that the tires you now have are closer to factory Z28 width I would say this does not apply to you. Although they are slightly taller and slightly wider than factory spec.
I think your rear suspension bushings are soft, and are allowing the rear end to wobble the entire car. The wider rear track may be magnifying this issue but, new bushings might fix it.
Stock tires on Z28’s were 245/50/16 which have a tread width of 10.0. They were given to SLP who installed the 275/45/17 with a width of 10.9. The tires you now have 255/40/18 have a tread width of 10.2 which is very close to the stock Z28 width. (All of the width’s were taken from one tire manufacturer, I’m sure they will vary from manufacturer to manufacturer.)
There was a thread a while back with an SS owner complaining of wobbly steering at highway speeds, especially in rutted roads. A complaint that I have with my SS. Several other SS owners chimed in with the same complaint. Someone said that he put SS wheels and tires on his Z28 and it wobbled really bad, he replaced them with his factory Z28 wheels and tires and it never wobbled again. For some reason I cannot find this thread, it was good information. Considering that the tires you now have are closer to factory Z28 width I would say this does not apply to you. Although they are slightly taller and slightly wider than factory spec.
I think your rear suspension bushings are soft, and are allowing the rear end to wobble the entire car. The wider rear track may be magnifying this issue but, new bushings might fix it.
That's my next course of action though so I'll keep reporting back as I go along. I'll replace the rear bushings and see what that does. I don't have my original wheels or I'd put them on just to see what difference it made.
10-21-2011, 04:27 PM
#26
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Re: Gets 'wobbly' above 110 (4th Gen SS)
I wish I'd known 19" tires cost a $bajillion even used tho...
10-21-2011, 04:31 PM
#27
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Re: Gets 'wobbly' above 110 (4th Gen SS)
I've had a lot of cars (most of them junk) and I've never had any vehicle do this.
At about 110mph, it starts wobbling like a trailer that's not loaded right. It quickly escalates and if you don't back off, it would completely go out of control. left/right/left/right/left/right rapidly. The steering wheel feels solid while it does this. Pavement makes some difference... if it's grooved asphalt, where there are ruts from use, it's likely to start doing it sooner, like about 90. But even on a perfectly flat smooth road it'll do it at some speed.
It's a 97 SS with C6 wheels on it. The last time I drove it over 140 was some time ago, and it had the stock 17x9's on it then. Point being, it was stable at that speed at that time. Since then though, I've had the K-member out twice and put the C6 wheels on it.
So I had it aligned a couple weeks ago, all is well, at least nothing wildly loose or broken, and while it was a little out of alignment, it wasn't waaaay out or anything. Still same results.
The only part of this suspension that's new to me is the rack. Only rack and pinion vehicle I've ever had. How do I know if that's worn out?
The other wildly speculative guess I have is that with the C6 wheels, the car is about 1/2 *taller* than stock, and it's on the original shocks. Is it getting too much air under it, with nothing to dampen it?
At about 110mph, it starts wobbling like a trailer that's not loaded right. It quickly escalates and if you don't back off, it would completely go out of control. left/right/left/right/left/right rapidly. The steering wheel feels solid while it does this. Pavement makes some difference... if it's grooved asphalt, where there are ruts from use, it's likely to start doing it sooner, like about 90. But even on a perfectly flat smooth road it'll do it at some speed.
It's a 97 SS with C6 wheels on it. The last time I drove it over 140 was some time ago, and it had the stock 17x9's on it then. Point being, it was stable at that speed at that time. Since then though, I've had the K-member out twice and put the C6 wheels on it.
So I had it aligned a couple weeks ago, all is well, at least nothing wildly loose or broken, and while it was a little out of alignment, it wasn't waaaay out or anything. Still same results.
The only part of this suspension that's new to me is the rack. Only rack and pinion vehicle I've ever had. How do I know if that's worn out?
The other wildly speculative guess I have is that with the C6 wheels, the car is about 1/2 *taller* than stock, and it's on the original shocks. Is it getting too much air under it, with nothing to dampen it?
10-21-2011, 11:33 PM
#28
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Re: Gets 'wobbly' above 110 (4th Gen SS)
The wider track could possibly allow more leverage on soft bushings, causing the rear end to move around more than it would if it were stock.
Stock tires on Z28’s were 245/50/16 which have a tread width of 10.0. They were given to SLP who installed the 275/45/17 with a width of 10.9. The tires you now have 255/40/18 have a tread width of 10.2 which is very close to the stock Z28 width. (All of the width’s were taken from one tire manufacturer, I’m sure they will vary from manufacturer to manufacturer.)
Stock tires on Z28’s were 245/50/16 which have a tread width of 10.0. They were given to SLP who installed the 275/45/17 with a width of 10.9. The tires you now have 255/40/18 have a tread width of 10.2 which is very close to the stock Z28 width. (All of the width’s were taken from one tire manufacturer, I’m sure they will vary from manufacturer to manufacturer.)
There also seems to be something wrong with your tread width numbers. Appears you are quoting section width.
A 245 tire has a "section width" of 9.6" to 10.0". The section width is the widest point on the tire. It would be virtually impossible to find a 10.0" tread on a tire that only has a 9.6" section width. The typical tread with for that tire is usually well under 9", and sometimes less the 8".
Ditto on the 275's. A 275 has a section width of 10.8 to 11.1". Tread width seldom exceeds 10.0".
10-23-2011, 02:14 PM
#29
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Re: Gets 'wobbly' above 110 (4th Gen SS)
I know I'm going to get read the riot act for doing this, but it's still a good 'parking lot' story. I'll have the K-member out of it and apparently I'm going through the entire rear suspension soon anyway, so I didn't want to waste $100 on an alignment that won't be good in 30 days...
http://threefivezero.wordpress.com/2...-october-2011/
http://threefivezero.wordpress.com/2...-october-2011/
10-25-2011, 03:32 PM
#30
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Re: Gets 'wobbly' above 110 (4th Gen SS)
Fred - Thank you for eagle eye. I definitely posted section width and incorrect aspect ratio, misinformation doesn't help anyone.
350350 – I found your write up on parking lots quite amusing! No shame in a redneck alignment if it is only to get you to the alignment shop.
350350 – I found your write up on parking lots quite amusing! No shame in a redneck alignment if it is only to get you to the alignment shop.