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Back End is floating?

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Old 01-15-08, 01:14 AM
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Back End is floating?

Recently my cars rear end feels pretty loose. As if its floating when i turn at a higher speeds especially on the freeway changing lanes quick. Its not the shocks. Pillowballs where noisy so i changed them and its still doing it.

Any ideas?
-Toe Links/Trailing Arms?
-Syspension/Swaybar bushings?
Old 01-15-08, 02:37 AM
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first check your tire pressure and alignment. if those are ok toe links could help if they are worn out. its possible that your shocks are dead if you are on your original shocks, does your car oscillate a few times when going over bumps?
Old 01-15-08, 06:47 AM
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i read you that it isn't the shocks but what you describe sounds like shocks. check to see if there is any sign of hyraulic fluid on the outer shock bodies.

the other possibles would be springs but they generally don't lose rate.

or tire pressure... as Mario says, "check your tires." you should be running 30 front 28 rear set cold. i don't think alignment or bushings would be the problem.

does your car float over bumps when you are going straight?
does the car track straight over a bump?

hc
Old 01-15-08, 10:22 AM
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reason why i dont think its shocks is because the car dosent "float" up and down causing the shocks to compress... It moves side to side as if the wheels are planted and the body is lose.

Shocks dont have any fluid on them. On tight roads my car handles fine. Its just when the i go over 60 i feel this floatingness.
Old 01-15-08, 10:57 AM
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are your diff bushings dead? any liquid around the diff bushings?
what size tires do you have, front and rear?
Old 01-15-08, 11:46 AM
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Rear strut bolts maybe loose?
Old 01-15-08, 04:50 PM
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Diff bushing are in excellent condition. i have stock rims 245 45 all around. New pillowballs, springs, 40K miles on the chassis.

Could toe links trailing arms cause this???? that what i think it is. When i twist them they turn, i know this is normal but is their a certain amount of laxity thats too much? (how can itell if their bad)
Old 01-15-08, 09:06 PM
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To check the toe links, jack up the rear of the car. Grab the wheels at 3 and 9 oclock, and push and pull on the wheel. If the toe links are worn then you will feel it being loose and you push and pull. It should be solid. It would take a lot of freeplay to cause what you are experiencing. Do the same thing at 6 and 12oclock.

Double check and make sure all the bolts in the rear suspension are tight. And make sure your sway bar is connected on both sides.

Does it do it when you make a left lane change as well as a right lane change? Does the rear end feel like it is steering itself or does it just feel like it reacts very slowly.

You are going to have to do some dirty work, crawl under the car and start checking everything. If everything cheks out good, try rotating the tires and see if it helps.
Old 01-15-08, 09:25 PM
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It does it on both sides. Yes. I guess it does kind of steer itself. Reaction is good.
I will check everything and let you guys know. Thnx for the info.
Old 01-17-08, 05:16 PM
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few other things i notices today. When i turn right the looseness is worse.
Under heavy braking from high speed its pretty bad, rear end is very unstable.

Im gonna jack the car up now and check out the toe links.
Old 01-22-08, 07:13 PM
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i jacked my car up and tried the 9-3oclock positin test. With enough force it does move BARELY and makes a slight sound.

Ive been reading a lot of thread of how people saw very little performance gain with after markey toe links.... Anyone have good experiences?

WHAT else can cause this..... Its pretty bad how loos the rear end is and i need to fix it.
Old 01-22-08, 11:51 PM
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It would take a lot of movement to make the rear end feel loose. So i doubt it is your toe links it there is only a small amount of movement. If you have too much rear toe out, it would make the rear end very loose.

I doubt its the rear differential, but i had a car that had a very similar problem and it turned out to be the rear differential. But the car was in an accident and the shock from the accident somehow damaged the differential. It felt as if the rear differential would lock and unlock when you were turning.
Old 01-23-08, 12:27 AM
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Car has not been in accidents. My car has 0 toe. The car dosent loose traction, its just as if the rear end is sitting on jello when i jerk the wheel.

Control arm bushings?
Old 01-23-08, 01:18 AM
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I would think that it would take something that is severly broken to cause what you are experiencing. Hows the condition of your tires, if you can rotate the tires just to rule out the tires.

How hard are you jerking the wheel, are you on the throttle at the same time.

Jack up the rear of the car and use a pry bar to check all the bushings in the rear end. You just pry on the arm to move it left and right, its suppose to move a little, but its not suppose to excessive.
Old 01-23-08, 06:26 PM
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Tires are new, when it happeneds there is no noise.

When it stops raining im going to to do what you just said,
but: I dont want you guys to think thats the cars like falling apart when i turn, On the freeway about 60mph if i jerk the wheel like i was kinda doing a slalom or switching lanes quick you feel it very noticably. When i brake hard from 60+ back end moves left right and feels unstable. When i take long turns i dont feel any symptoms. It is also worse when i turn right. Its not rediculosy bad but it really is driving me nuts because my moms acura TL feels more stable on the freeway vs my Rx7 and im going to hit the track soon.
Old 01-23-08, 09:37 PM
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ur car is giving out. consider something from the honda line
Old 01-28-08, 05:46 PM
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I'm not a suspension guru, but there are just limited number of points of movement. Sure that is a "duh" statement. I was curious of the DTSS bushings could cause this? I have rear end movement that is dangerous. If I go over a bump or manhole cover, my car will thud real loud and will vier off a little like I turned my steering wheel.

The differential *should* have nothing to do with the floating since it has its own mounts and cannot push or pull on the wheels in a manner that will cause the float. Until I get a lift, I just drive mine like a granny and avoid potholes and bumps of any kind that I can.

Thinking of the geometry of the rear suspension, the main parts that can affect the toe in or out on the tire would be: Rear Lower Control Arm Bushing, Lateral links, and the DTSS. The rear camber links should only affect the tilt in and out on the wheel.
Old 02-05-08, 01:11 PM
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Did you recently replace your tires in the rear? I recently changed tires and noticed alot more body roll kind of like you are describing . I am pretty sure it is just the tire has a weaker sidewall than the tires that where on before. Possibly a lower rated tire.
Old 02-16-08, 03:34 PM
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Im supossed to get my new Fightesr-garage toe links and trailing arms in today. Hopefully it will resolve my problem.

BTW: I just added a diff brace and the problem is the same, if not worse.
Old 02-18-08, 02:24 AM
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i have had the same problem ruined my fairly new (3.5k) 555's, i think it was my alignment, I installed the RP traction kit (links and arms) and i think that threw it off a lot, i recently sold my wheels but I was getting sway going 15mph!! i tried to make everything even on both sides but i'm even afraid of when i get my new wheels to take it out it's that bad. i only took it out a few times and after i parked it I noticed my bumper was covered in rubber.
Old 02-26-08, 07:06 PM
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I installed new Fighters-garage toe links. Tight as a rock. Today I was driving around on a canyon road and the looseness is still their,,,in fact i think its even worse. I did a hard 100-40 brake and I almost lost control. The back end swung left right. ALOT on an even surface.

Possibilitis in my mind
1:Back tires are Toyo TR1 which are known for weak sidewalls. But can it be that bad?? I was running 32psi
2:Alignment?
3:Suspension bushings? Control Arms? My car has 40K miles on chassis btw.
Old 02-26-08, 07:48 PM
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did you get aligned after the toe links?
Old 02-26-08, 08:18 PM
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^bingo

Sounds like you need an alignment pretty bad.
Old 02-26-08, 08:52 PM
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Originally Posted by gracer7-rx7
^bingo

Sounds like you need an alignment pretty bad.
i dunno, i matched the toe links and trailing arms to the originals by the militmeter. THe old ones were aligned a month or so ago. 0 toe -1.3 forgot caster.

Can a bad alignment create such unstability?? I want to find a shop that can test my alignment without me paying 80$ for it.
Old 02-27-08, 09:58 AM
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Yes it can. Sounds exactly like a bad alignment. Fwiw, I've had my share of bad alignments...

If everything else checks out, get the alignment redone. Find a good shop. I usually check bimmerforums or the miata forums in the Regional section for recommendations on alignment. Those guys race pretty often and seem to post up about the shops they've been to.


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