Car Vibrating above 50 MPH After Hard Braking

['95EclipseGSX]

So I had to ram on my brakes last night extremely hard. A really awesome semi was going 40 MPH and right as I was about to pass his wheels started to drift into the left lane. Got scared he might carelessly go into the lane another foot or two and run me off the road to I decided to hit the brakes instead. I jammed them on so hard the back wheels locked up momentarily.

Now I have this vibration/low-pitched rumble whenever I drive above about 50 MPH. I tried tightening the lug nuts (they weren't lose) and pumping the brakes a bunch of times.

What is causing this? It doesn't makes sense to me that my wheels would be somehow unbalanced just by hard braking. Could one of my brake pads be messed up and rubbing against the disc? Should I try pulling all the calipers back? Is it a warped disc? I don't really know that much about brakes. What a pain in the ass. I thought the brakes were there to be used. I use them and this is what I get. Yippee!!

 

[eligst21]

It would depend on how bad the warpage would be. If it wasnt a signification amount, it wouldnt be too bad on breaking. My best bet is go get the rotors turned and pads. Or buy new rotors and pads. I almost bet that is your problem. Or go buy new tires and see what that does. Its your decision.

 

[Archer Fabrications]

could it be that you slammed on the breaks so hard that something could have messed up your alignment? Other than that all i can think of is warped rotor. whens the last time you had an alignment? could also be possibly something with an axel?

 

[jtmcinder]

The OP said he locked up the wheels for a second, also says he can feel flat-spots on his tire, so why is this thread still generating wilder and wilder guesses?

 

[4g63tc]

^+100 Some people just like to overlook facts, already stated in OP's post.

mountains out of Molehills...the vibration is Crankwalk...

 

['95EclipseGSX]

That's funny you should say that 4g63tc, the vibration was actually crankwalk. Took it to a professional mechanic toady and that's what he said. Car is totaled.

No, I'm kidding. I am 100% sure the vibration is being caused by flat spots on all 4 of my tires. No other factors are playing into it. Had it checked out today.

 

[DSM1G90]

(bet it's rotors....you'd had to chew down quite a bit of rubber in one area to be flat spots...and that would be noticable just by looking at the tire's tread...)

 

[4g63tc]

^........

Looks like it's my tires because the brakes are fine. I can even feel a little bit of a flat spot on 2 of my tires. So sad... Oh well. I hope the flat spots come out as I drive more. These tires have about 15,000 miles left on them so I'd hate to junk 'em.

it could be still the brakes...

Take it to a Tire Store, and have them re-balanced, it should help a little.

Oh and one thing that seems to have been overlooked does your GSX have LSD, ABS, or both.

 

[bryanwheat]

^........

it could be still the brakes...

Take it to a Tire Store, and have them re-balanced, it should help a little.

Oh and one thing that seems to have been overlooked does your GSX have LSD, ABS, or both.

It isn't a problem with the tire being balanced, it is a problem with a flat spot on the tire. Every time that spot hits the ground is make noise and will net a little vibration. Balancing it isn't going to do jack. Rotors don't generally become warped from locking up. There is far less heat produced by locking them than i you were on it hard but failed to lock them.

 

[Calan]

This thread is awesome. The OP got the correct answer 12 minutes after he first posted, and 5 days later there is still a debate as to what is causing the vibration.

On a semi-related note, brake rotors rarely actually warp. Here is a good read from one source about that and other common brake myths: -Warped- Brake Disc and Other Myths

 

[knewblewkorvett]

Rotors don't generally become warped from locking up. There is far less heat produced by locking them than i you were on it hard but failed to lock them.

I agree.
Sorry to hear about your flat spots. I'm guessing that the longer you use the tires, the vibrations will be less noticable. You can get tires shaved but I would recommend not doing that because of cost

 

[preludeachris]

^........

it could be still the brakes...

Take it to a Tire Store, and have them re-balanced, it should help a little.

Oh and one thing that seems to have been overlooked does your GSX have LSD, ABS, or both.

you gotta be kidding me...

you cant balance tires with flat spots... the part that flat is why is vibrating in the fist place...and "sticky" brakes dont cause vibrations UNLESS your braking in the first place

mines a 95 i dont have ABS ?

if you dont have abs on your car it doesn't madder if you lock your breaks up for a split second or 500 feet your going to have flat spots regardless (ruling out rain or ice)

 

['95EclipseGSX]

I don't know if I have a limited slip differential but no, I have no ABS. I think ABS was an option in 1995. My dad used to say "Son, ABS is for ####ies." After this incident I may have to respectfully disagree with him on that!

 

[4g63tc]

you gotta be kidding me...

you cant balance tires with flat spots... the part that flat is why is vibrating in the fist place...and "sticky" brakes dont cause vibrations UNLESS your braking in the first place

mines a 95 i dont have ABS ?

if you dont have abs on your car it doesn't madder if you lock your breaks up for a split second or 500 feet your going to have flat spots regardless (ruling out rain or ice)

You can balance a tire with flat spots, but it's only a bandaid. Either way if he took it to a tire shop they may or may not be able to remedy the situation. Aw hell take a grinder to it and feather it out

Mines is a 95 gsx, i have LSD, and ABS but no sunroof or power antenna so...i guess you got one missing options.

But for sure, ABS has nothing to do with reducing the "locking" up of the brakes...whodathunk "Anti-Lock Braking System" was a lie.

 

[bryanwheat]

You can balance a tire with flat spots, but it's only a bandaid. Either way if he took it to a tire shop they may or may not be able to remedy the situation. Aw hell take a grinder to it and feather it out

Mines is a 95 gsx, i have LSD, and ABS but no sunroof or power antenna so...i guess you got one missing options.

But for sure, ABS has nothing to do with reducing the "locking" up of the brakes...whodathunk "Anti-Lock Braking System" was a lie.

What are you talking about. Have you owned an abs car? It's VERY hard almost impossible to just flat out lock up the brakes. You know why, because the brakes are pulsed when the system senses a slipping tire. Go drive a non abs car on ice than drive one with abs and tell me that you experience. Also i don't think that you understand what a flat spot on a tire is. There is one spot with missing rubber. Putting wheel weights on the wheel isn't going to take away the vibration in any situation.

 

[4g63tc]

What are you talking about. Have you owned an abs car? It's VERY hard almost impossible to just flat out lock up the brakes. You know why, because the brakes are pulsed when the system senses a slipping tire. Go drive a non abs car on ice than drive one with abs and tell me that you experience. Also i don't think that you understand what a flat spot on a tire is. There is one spot with missing rubber. Putting wheel weights on the wheel isn't going to take away the vibration in any situation.

Dear Bryan, did you see the post above mine? Sarcasm misses you.
Hell i even Quoted the post in my Post.

I think i know how ABS works.

I admit balancing may not do anything, Sprited driving through mountain passes will do more, But having a tire store look at the tire won't hurt either.

 

[preludeachris]

You can balance a tire with flat spots, but it's only a bandaid. Either way if he took it to a tire shop they may or may not be able to remedy the situation. Aw hell take a grinder to it and feather it out

Mines is a 95 gsx, i have LSD, and ABS but no sunroof or power antenna so...i guess you got one missing options.

But for sure, ABS has nothing to do with reducing the "locking" up of the brakes...whodathunk "Anti-Lock Braking System" was a lie.

....im not even gunna waste my time responding to that

 

[DSM1G90]

Here is a good read from one source about that and other common brake myths: -Warped- Brake Disc and Other Myths

This is a good article.

On a related topic of this "rotor" thing (and to swing attention away from this concluded thread), heard that if one overtightens the lug nuts that this will also warp rotors...any truth to this, or this is another one of those saturday mechanic created myths?

 

[knewblewkorvett]

heard that if one overtightens the lug nuts that this will also warp rotors...any truth to this, or this is another one of those saturday mechanic created myths

Considering the hubs are flat, rotors are flat, and the center of the wheels are flat....no, they cannot warp. Too much torque on the lugnuts can strip threads or worse, crack the rims, espically if they are cast aluminum. Always use a torque wrench.

 

[jtmcinder]

But for sure, ABS has nothing to do with reducing the "locking" up of the brakes...whodathunk "Anti-Lock Braking System" was a lie.

You forgot the snark tag. (I'm probably being too charitable.)

 

[4g63tc]

You forgot the snark tag. (I'm probably being too charitable.)

I did, I'm sorry...but atleast you got it.

 

[scottdsm4g63t]

luck for you i work at a tire store. it could be one of three problems.
1. you have seperate tires so check for tire seperations or big air pockets form the heat of slaming your breaks. it can cause the rubber to heat up real quick and split the beads.
2. you most likely have flat spots from runnin 50mph then locking them up semi's have it happen all the time when the trailors lock up.
3. he it doesnt always hurt but if its shaking really bad and the tires seem in good shape just rotate them and that should take away your shakes