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Rear End Sway by bomluuk
Started on: 05-28-2014 12:27 PM
Replies: 106 (3404 views)
Last post by: 4thfiero on 02-24-2015 09:06 AM
imabaddude
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Report this Post11-03-2014 11:14 PM Click Here to See the Profile for imabaddudeSend a Private Message to imabaddudeEdit/Delete MessageReply w/QuoteDirect Link to This Post
I'm with Blooz, it sounds like he was having too much fun, and didn't know the little oddities in how Fiero's handle.

Well, I guess he might know a little about Fieros then. Still, that's kind of crappy, and I see you replied when I was typing.

[This message has been edited by imabaddude (edited 11-03-2014).]

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fierofool
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Report this Post11-03-2014 11:39 PM Click Here to See the Profile for fierofoolClick Here to visit fierofool's HomePageSend a Private Message to fierofoolEdit/Delete MessageReply w/QuoteDirect Link to This Post
I'm the 4th Georgia Fiero Club member who's owned that car. Don has maintained it throughout it's club history and is very familiar with the Fiero in all manner. This would be the Don that's being followed here:
http://www.youtube.com/watch?v=4LBAKEfWr04

He will give me a better analysis when he gets into it later this week.
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bomluuk
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Report this Post11-04-2014 11:21 AM Click Here to See the Profile for bomluukSend a Private Message to bomluukEdit/Delete MessageReply w/QuoteDirect Link to This Post
Sounds to me like it was something other than the CV joint. Unless I'm forgetting something, the only things that have to do with suspension geometry on the rear are the strut, ball joint, and tie rod. Maybe the control arm if it got bent.
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fierofool
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Report this Post11-04-2014 02:29 PM Click Here to See the Profile for fierofoolClick Here to visit fierofool's HomePageSend a Private Message to fierofoolEdit/Delete MessageReply w/QuoteDirect Link to This Post
I agree, too. The rear bushings, tie rod, ball joints all have only about 300 miles on them. It broke the knuckle and outer CV tilting the front of the wheel in at about a 45 degree angle. Once he pulls it out he will be better able to tell what was first failure. But again, check everything for proper torque. One loose bolt can destroy a lot of things. Including the car.
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bomluuk
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Report this Post11-10-2014 03:07 PM Click Here to See the Profile for bomluukSend a Private Message to bomluukEdit/Delete MessageReply w/QuoteDirect Link to This Post
New KYB gas a just shocks up front, excel g struts in the rear, and a fresh alignment. Still sways on the freeway.

Maybe springs?
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bomluuk
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Report this Post11-10-2014 05:43 PM Click Here to See the Profile for bomluukSend a Private Message to bomluukEdit/Delete MessageReply w/QuoteDirect Link to This Post

bomluuk

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Here's the height measurement at the front wheel well, middle of car to rocker panel, and rear wheel well.
Anybody have any numbers to commpare to? Keep in mind it is a 3800sc.
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fierofool
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Report this Post11-10-2014 06:44 PM Click Here to See the Profile for fierofoolClick Here to visit fierofool's HomePageSend a Private Message to fierofoolEdit/Delete MessageReply w/QuoteDirect Link to This Post
I don't think the actual height would be an issue as long as side to side at the same points are relatively close. You're 1/8 to 1/4 inches different. All low points are to the right with front and rear being 1/8 equally but the center is drooped an extra 1/8? It could just be variations in the panels.

Check sway bar end links to be sure they're tightened the same number of turns. If they've been removed and replaced, one side may be tighter than the other. It won't cause a difference in height, but it will cause a difference in reaction to road surfaces.
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fierofool
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Report this Post11-10-2014 06:50 PM Click Here to See the Profile for fierofoolClick Here to visit fierofool's HomePageSend a Private Message to fierofoolEdit/Delete MessageReply w/QuoteDirect Link to This Post

fierofool

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...

[This message has been edited by fierofool (edited 11-10-2014).]

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bomluuk
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Report this Post11-10-2014 07:29 PM Click Here to See the Profile for bomluukSend a Private Message to bomluukEdit/Delete MessageReply w/QuoteDirect Link to This Post
I posted the numbers because I figured they could help diagnose saggy springs.

I did change the sway bar end links before the previous alignment. I'll double check them.
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newfiejeff
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Report this Post11-10-2014 07:34 PM Click Here to See the Profile for newfiejeffSend a Private Message to newfiejeffEdit/Delete MessageReply w/QuoteDirect Link to This Post
Well I can't comment much on this only from what my car is like. I have a 86 2M4 and since I bought it last year, the two front shocks are getting bad and the back ones I don't believe they are there for the bouncing it does, but at high speeds on the highway there is no sway. I upgraded to 17 inch wheels and I have no issues yet.
So to say struts can give problems I am not sure but mine are basically there in view nothing else...lol/
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bomluuk
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Report this Post11-11-2014 11:54 AM Click Here to See the Profile for bomluukSend a Private Message to bomluukEdit/Delete MessageReply w/QuoteDirect Link to This Post
Maybe I'm doing this all wrong by thinking the problem is in the back.
Mainly what's got me thinking that is I hear a popping noise in the front, and I can feel it on my feet. (this happened before, but nowhere near as frequently, so I didn't think too much of it)
Could a bad steering rack or something else up front be a problem?
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edfiero
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Report this Post11-11-2014 01:38 PM Click Here to See the Profile for edfieroSend a Private Message to edfieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
When you jack up the rear, grab the rear tire, first at 3 and 9, try to muscle it back and forth. Grab at 6 and 12. Repeat. Any movement?
You should not be able to move it at all, except for the flex of the rubber. Any other movement means bad Hub, Ball Joint or Tie Rod. Then its just a matter of getting a helper under the car while you flex the tire and see where its moving.

If tire is rock solid when you shake it like this, and you still have sway, I'd be leaning toward something being up with the tires.
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fierofool
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Report this Post11-11-2014 02:09 PM Click Here to See the Profile for fierofoolClick Here to visit fierofool's HomePageSend a Private Message to fierofoolEdit/Delete MessageReply w/QuoteDirect Link to This Post
It should be noted that when you jack it up and make the test edfiero suggested, that the car be supported on jack stands by the lower control arms. This will allow testing of the ball joints, tie rods and ends and hub. The only thing that can't be checked in this manner are the control arm bushings.

But yes, something in the front could make the car bobble. If it were the rack you would probably feel it in the steering. A ball joint or control arm bushing might not transmit to the steering wheel.
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bomluuk
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Report this Post11-11-2014 03:22 PM Click Here to See the Profile for bomluukSend a Private Message to bomluukEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by edfiero:

When you jack up the rear, grab the rear tire, first at 3 and 9, try to muscle it back and forth. Grab at 6 and 12. Repeat. Any movement?
You should not be able to move it at all, except for the flex of the rubber. Any other movement means bad Hub, Ball Joint or Tie Rod. Then its just a matter of getting a helper under the car while you flex the tire and see where its moving.

If tire is rock solid when you shake it like this, and you still have sway, I'd be leaning toward something being up with the tires.


That's been done already. Tie rods, ball joints, and hubs are all new. It's swayed with the old set of tires and a completely new set of tires.
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edfiero
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Report this Post11-11-2014 08:40 PM Click Here to See the Profile for edfieroSend a Private Message to edfieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
Wouldn't hurt to check it again. Wouldn't be the first time a new part wasn't good. I'd also try rotating the tires if you haven't done that, to see if the amount of sway changes at all. I'd tend to agree that any problems with the front would be noticed in the steering wheel
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bomluuk
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Report this Post11-11-2014 09:54 PM Click Here to See the Profile for bomluukSend a Private Message to bomluukEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by edfiero:

Wouldn't hurt to check it again. Wouldn't be the first time a new part wasn't good. I'd also try rotating the tires if you haven't done that, to see if the amount of sway changes at all. I'd tend to agree that any problems with the front would be noticed in the steering wheel


Copy that. I'll give it a shot.
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edfiero
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Report this Post11-11-2014 10:32 PM Click Here to See the Profile for edfieroSend a Private Message to edfieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
Wouldn't hurt to check it again. Wouldn't be the first time a new part wasn't good. I'd also try rotating the tires if you haven't done that, to see if the amount of sway changes at all. I'd tend to agree that any problems with the front would be noticed in the steering wheel
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AL87
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Report this Post11-12-2014 10:58 AM Click Here to See the Profile for AL87Send a Private Message to AL87Edit/Delete MessageReply w/QuoteDirect Link to This Post
check your alignment first*

if you take it to a shop, IF they are good, they will either find the adjustment is out, OR the rear lower ball joints are loose.
OR something with the rear end is loose.

Almost horror story: I had the same issue before, and I was suffering two weeks of headache trying to diagnose the problem prior to taking it somewhere.
the commercial "tires plus" shop that I took it to checked my alignment, and set it, but I was still having problems...
I come to find out about a week later that 2 of the three bolts holding my lower ball joint on the rear drivers side control arm had fallen out.
and the last one had the nut hanging on there by just a few turns. They were not paying attention when they checked...

I felt really God blessed that the rear left didn't rip out or anything at speed, during all that time...
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bomluuk
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Report this Post11-14-2014 02:04 PM Click Here to See the Profile for bomluukSend a Private Message to bomluukEdit/Delete MessageReply w/QuoteDirect Link to This Post
Checked the front wheels again and I couldn't find any movement. But I got under and decided to see if there were any loose bolts that are making the popping noise. I couldn't find any loose. I checked the tie rods. The outers were good, but I did find that my passenger inner tie rod is loose where it connects to the steering rack. This is what has been causing the loud popping. Doing some research on here it appears I need to replace the rack bushing. One is on order from Rodney Dickman.
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fierofool
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Report this Post12-15-2014 07:08 PM Click Here to See the Profile for fierofoolClick Here to visit fierofool's HomePageSend a Private Message to fierofoolEdit/Delete MessageReply w/QuoteDirect Link to This Post
I don't know if this will be helpful to you, or not, but in my case, we found the cause of the wiggle-wobble. The right strut had no resistance. As the wheel traveled up and down, it was more pronounced than the left rear. I'm guessing this allowed the right wheel to turn inward and outward. It put so much stress on the knuckle that it broke it off just below the strut mounting bolts. When it broke, the wheel turned and caused him to spin out, destroying the right rocker and rear wheel as it broadsided and bellied out on the shoulder of the road before going into a front yard.

Today I picked up the car and without an alignment, drove it 75 miles home. Though the steering wheel is about 1/8 turn off center, the car doesn't give the little twitch any more. Total of parts replaced in the 'throw money at it' process---all ball joints, front shocks, all tie rod ends, control arm bushings in the rear and finally a new set of struts. The struts were the problem.
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bomluuk
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Report this Post12-18-2014 08:55 PM Click Here to See the Profile for bomluukSend a Private Message to bomluukEdit/Delete MessageReply w/QuoteDirect Link to This Post
That's pretty crazy that the knuckle broke. Its pretty stout at that spot.

I've got all new struts and shocks. That was part of the problem with the rocking. The right front and left rear were bad, and I think thats where the sway came from.
The steering still isn't right. It walks a lot and I can't take turns very fast. That along with the noise up front leads me to believe its the steering rack.
When I get more time I'm replacing the bushing and I think/hope that'll solve the problem.
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Report this Post12-19-2014 09:27 AM Click Here to See the Profile for ImnutsSend a Private Message to ImnutsEdit/Delete MessageReply w/QuoteDirect Link to This Post
This has mostly likely been covered but onetime I had a vehicle that I would almost lose control of driving on the interstate and after having everything changed out it ended up being a set crappy General tires and cupped roadways. It was so bad that when it first happened I thought I had a flat tire and pulled over to check. Changed tires problem was gone.
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fierofool
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Report this Post12-19-2014 10:07 AM Click Here to See the Profile for fierofoolClick Here to visit fierofool's HomePageSend a Private Message to fierofoolEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by bomluuk:

That's pretty crazy that the knuckle broke. Its pretty stout at that spot.



I agree. When he pulled it, he said there was no indication that there had been an existing fracture. It was all a fresh clean break. I actually think something else happened and the broken axle and knuckle were the result of something else happening. The wheel was totally destroyed. Something I wouldn't have expected from sliding around and going off a roadway that didn't have curbing.

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Report this Post12-24-2014 01:05 PM Click Here to See the Profile for hobbywrenchSend a Private Message to hobbywrenchEdit/Delete MessageReply w/QuoteDirect Link to This Post
For whatever good it might do here are some experiences with my 85 GT. Before A arm bushing replacement I had 2 serious over steer incidents on wet left hand turns- new (rubber) bushings fixed that . While replacing the ball joints rear, the rivets were removed to accept the 3 small machine screws with their nyloc nuts. These screws were made of (chinese? ) inferior steel and would not torque to inch pound callout (threads stripped off). I had to procure proper hardware locally. Rock issued CR.

Finally, and this one took some time to figure out...After suspension overhaul all was well except for one stretch on interstate where car wandered and felt really goosey. I put the car up and checked all likely places. Car was fine until that stretch was again navigated. Car up again-nothing. A year later on another stretch same thing except this time signs warning motorcyles of road work. I noticed the cement surface grooved. The car did the hootchy-coo. Here's what was happening. Here motorists are allowed studs for winter months and the slow lane (mostly)becomes concave from the studs. The hiway dept has a diamond toothed "plow" which levels the cement , but leaves serrations. This apparently raises hell with bikers and drivers of light cars. As those stretch wore down I had less and less of a problem.
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bomluuk
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Report this Post12-25-2014 07:20 PM Click Here to See the Profile for bomluukSend a Private Message to bomluukEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by hobbywrench:

For whatever good it might do here are some experiences with my 85 GT. Before A arm bushing replacement I had 2 serious over steer incidents on wet left hand turns- new (rubber) bushings fixed that . While replacing the ball joints rear, the rivets were removed to accept the 3 small machine screws with their nyloc nuts. These screws were made of (chinese? ) inferior steel and would not torque to inch pound callout (threads stripped off). I had to procure proper hardware locally. Rock issued CR.

Finally, and this one took some time to figure out...After suspension overhaul all was well except for one stretch on interstate where car wandered and felt really goosey. I put the car up and checked all likely places. Car was fine until that stretch was again navigated. Car up again-nothing. A year later on another stretch same thing except this time signs warning motorcyles of road work. I noticed the cement surface grooved. The car did the hootchy-coo. Here's what was happening. Here motorists are allowed studs for winter months and the slow lane (mostly)becomes concave from the studs. The hiway dept has a diamond toothed "plow" which levels the cement , but leaves serrations. This apparently raises hell with bikers and drivers of light cars. As those stretch wore down I had less and less of a problem.


I have noticed a small part of my drive home on the freeway (maybe 100 yards) where it is particularly squirrely in the slow lane. I drive in the middle lane to avoid it. It feels though as if this little stretch just amplifies the bad handling, as it does it no matter where I drive as well.
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bomluuk
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Report this Post02-23-2015 03:57 PM Click Here to See the Profile for bomluukSend a Private Message to bomluukEdit/Delete MessageReply w/QuoteDirect Link to This Post
Update for reference:

Replaced the bushing in the steering rack and re-aligned. Still sways, though not as much as it used to.
Replaced the front upper ball joints, but have not driven it since. Will get aligned and see if that does the trick.

If not, I've come across some threads that say maybe the u joint link in the steering column is the culprit.
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4thfiero
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Report this Post02-24-2015 09:06 AM Click Here to See the Profile for 4thfieroSend a Private Message to 4thfieroEdit/Delete MessageReply w/QuoteDirect Link to This Post
Just my 2 cents, im sure it's not this but back when my car was an 86, it swayed, and i replaced EVERYTHING....nothing fixed it, i later found out while i was doing the chassis swap to an 88 that my 86 rear upper frame rails were so badly rusted they were almost gone O_o....when everything else fails. Check the frame...
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