rear end problem - HELP!
#1
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rear end problem - HELP!
OK guys, here is the scoop. Shes a 91 coupe n/a.
The problem: As I was driving from work today, I noticed a wierd vibration from the back of the car. The vibration seems speed dependent, ie i cant feel/hear it in first gear. but around 30-50 mph its very noticable. I can describe the vibration most closely to a flat tire. Its kinda like a rotating, thumping sound (very quiet, but vibrates the whole car). Also I noticed, that when I drive straight the sound is there, If i turn left the sound is gone during the turn, if I turn right the sound and vibration increases even more than when its going straight. When I apply the brakes - no change. In neutral - no change.
What the car has: new rear brakes, pads - got done one month ago.
I drag raced at E-town one week ago.
25mm wheel spacers w/3rd gen wheels.
Please help, this is my daily driver. I don't know what can be wrong, and how to diagnose it.
The problem: As I was driving from work today, I noticed a wierd vibration from the back of the car. The vibration seems speed dependent, ie i cant feel/hear it in first gear. but around 30-50 mph its very noticable. I can describe the vibration most closely to a flat tire. Its kinda like a rotating, thumping sound (very quiet, but vibrates the whole car). Also I noticed, that when I drive straight the sound is there, If i turn left the sound is gone during the turn, if I turn right the sound and vibration increases even more than when its going straight. When I apply the brakes - no change. In neutral - no change.
What the car has: new rear brakes, pads - got done one month ago.
I drag raced at E-town one week ago.
25mm wheel spacers w/3rd gen wheels.
Please help, this is my daily driver. I don't know what can be wrong, and how to diagnose it.
#5
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From your description, it is something on the LR of the car. Since it's speed dependent, the tranny is not suspect. And, since the noise goes away when you turn left and take weight off the left-rear of the car, that puts the problem in the LR of the car. You may have lost a wheel weight, wheel bearing could be bad, half shaft could be bad, or the side bearing in the differential could be bad.
Do you have LSD?
Do you have LSD?
#7
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To check for LSD, jack the car up on stands and look at the diff housing. The LSD equipped diff will have a tag on the top bolt. If you can't see it, then start the car and put it in 5th gear. Get out and see if both wheels are turning(not the best way to tell). If the car does not have LSD, one wheel should not be spinning.
Check that first.
Check that first.
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#9
Former Moderator. RIP Icemark.
It wouldn't be the LSD on that car unless the wrong weight gear lube was used.
The few series 5 cars that come with LSD have the fluid type LSD, which do not wear out.
The few series 5 cars that come with LSD have the fluid type LSD, which do not wear out.
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Thanks for the advise guys...I will jack the car up on my lunch brake and will report back with my findings.
Oh ****...its raining here...the sacrifices we make for our cars!
Oh ****...its raining here...the sacrifices we make for our cars!
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OK, I went home for lunch and jacked up the rear end.
I do have LSD, but thats not the problem. The problems seems to be a loose passenger side caliper. I could just jiggle the caliper around with one finger, also the pads are very loose in the mounting support. I will tighten that down tonight. Looks like the shop that did the brakes a month ago did a poor job, and the drag racing must have aggrevated it.
What do you guys think?
I do have LSD, but thats not the problem. The problems seems to be a loose passenger side caliper. I could just jiggle the caliper around with one finger, also the pads are very loose in the mounting support. I will tighten that down tonight. Looks like the shop that did the brakes a month ago did a poor job, and the drag racing must have aggrevated it.
What do you guys think?
#17
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Originally posted by vosko
you have LSD ? interesting. your car isn't supposed to ! that's very good
you have LSD ? interesting. your car isn't supposed to ! that's very good
I also got the 4 pot calipers.
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Originally posted by vosko
you have LSD ? interesting. your car isn't supposed to ! that's very good
you have LSD ? interesting. your car isn't supposed to ! that's very good
#20
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I think you guys are right actually...I missunderstood the "LSD test".
When i turn one wheel, the other turns opposite. That = No LSD.
I was just a confused little boy. I go from thinking I have it to being jealous that i dont, just like Flyby116.
When i turn one wheel, the other turns opposite. That = No LSD.
I was just a confused little boy. I go from thinking I have it to being jealous that i dont, just like Flyby116.
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My guess is that you got a lump on one of your rear tires. At low speed is not fast enough to feel until you speed up an it trows your tire out of balance. As when you turn all the weigth transfer makes it worse or simlpy not so noticeable. LSDs dont make your car shake they just ultimatly wear and slip. Jack the car up spin the tires look across the threat and feel it. Hopefully that take care of it. Ev7
#24
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Originally posted by Ev7
My guess is that you got a lump on one of your rear tires. At low speed is not fast enough to feel until you speed up an it trows your tire out of balance
My guess is that you got a lump on one of your rear tires. At low speed is not fast enough to feel until you speed up an it trows your tire out of balance
I'll try tightening that caliper when I get home, see if that takes care of it!