jbar5563

I just purchased my 2003 sc it has 78000 miles on it and im not sure if im running rf's in the rear and non rf's in the front. I know the ones in the rear are very different looking they are s800 bct's , and the front they are continentals. Anyway how can i tell between a run flat tire and a non run flat tire??
Do they look different in apearence? All i know is that sucker vibrates damn good at around 55-68 mph. should i get a wheel balance?There is no spare in the trunk and the tires look brand new im not sure what im running can someone help me out please?

SteadyEddy

iTrader: (1)

Welcome to the forum. If I can't help you I'm sure someone else here on the forum can. The people here know everything about everything, and don't mind sharing.
It will tell you on the sidewall of the tire (I have Dunlops and the word "RUNFLAT" is right below their name) I too had a vibration at about 65 to 80, I had the wheels balanced and it no longer vibrates. I had 2 new tires installed when I bought the car in 08 and they told me that the two rear tires didn't have any weights at all and it took a good amount of weight to get them balanced, and the fronts not so much but did need some. It was under $40. Plus they might see something else when they take the wheels off. I'd give that a shot first. I'm also surprised that a dealer would not put on runflats if they had to replace 2 tires. Mainly that you don't have a spare. Good luck and let us know if that helps

cjs18

I would also start with wheel balance. It's also possible that an inbalance can be amplified by bad suspension bushings, so you might have the technicians have a look at those also.

m3nv

If they're runflats, the tire will say "RFT" or you can easily google the model tire you have and see if they're runflats. You probably need a balance since even with runflats, you wont get the type of vibration you're experiencing. When you go for a balance, they'll let you know if its a different problem such as a bent wheel or cupped tires.

Harold57

The SC430 is notorious for shaking between 45 & 65 mph (plus or minus 10 mph). Some have solved the shaking with road force balancing and others needed to replace the bushings on the front end (mainly control arm, IIRC). The problem appears to be harder to rectify for those that have wheel sizes above the stock 18" (lots of folks move up to the 20" rims).

Good luck with the struggle and welcome to the forum.

BloodDoc

Last month had similar symptoms in my 2003 SC (38,000 miles). Suspected alignment, wheel balancing, bad tie rod or tread separation. Ended up needing to replace struts and shocks. Smooth as glass again. Good luck.

DEO

My 2007 SC had/has a vibration problem. Note: the tires (non-runflat) are fairly new with just a few thousand miles but the inside edges were wearing a great deal. First, I had an alignment which was needed badly. This took most of the problem away. Not completely satisfied, I had a balancing job done. It was here that is was discovered one of the tires is slightly out of round. If you have a balance job done ask to see the road force results.

scdroptop

iTrader: (1)

On the alignment-did you get the camber results? If what was done did not fix it, then perhaps it needs to be redone or perhaps the tires are too cupped on the inside.

jbar5563

Thank you for responding everyone i just realized MY DUMBASS DOESNT HAVE RFT'S. THEY ARE NORMAL TIRES 245 40'S 18. IM GETTING A TIRE BALANCE
MONDAY AND I WILL SEE IF THE VIBRATION GOES AWAY. I ALSO NOTICED THAT IN THE MORNINGS WHEN ITS REAL COLD THE CAR VIBRATES ALOT AT LOW SPEEDS DOES ANYONE ELSE HAVE THAT PROBLEM?? IM GUESSING ITS DO TO THE COLD AND THE TIRES HARDEN THEN WARM UP DURING THE DAY.

talison24

Struts and shocks at 38,000??? My Nissan was not required until 100,000.

KaiserSea1

Without road force balancing the ride was shaking horribly, now it only starts to shake at 130+ and I'm not sure if it is the car or me.

SteadyEddy

iTrader: (1)

Does the problem continue after you have driven and gotten the tires up to temperture? Sitting all night in the cold some tires will flat spot until they are driven and warmed up.

NineTreSc3

iTrader: (3)

This is pretty basic advice, but low tire pressure can cause vibration and also pull to one side. If the steering wheel is shaking its coming from your front end. If you feel it in your seat its from the rear. Most likey a tire or rim (rim damage is possible) problem because a suspension component would have to be very damaged for you to feel it in your steering wheel (tie rod, steering rack, etc). Especially on a rwd car since you dont have front axles. My advice would be start with a reputable shop that uses a hunter or other type of road force balance (Sears always does a good job). That way not only will they balance the tires but also check for tire runout to see if there are any lumps or flat spots. But check the pressure first make sure all four tires are running at psi listed on the tire or on inside door jam. Good luck. Happy holidays!

mandyfig

Seems that after the SC has aged a certain amount of vibration is going to show up. I do have them between 65~70 mph and was coming from the front. Rotated tires and it went away. However when I rotated the tire , one of the rears has cuffing starting on the inside. Now I suspect that the humming I hear is coming from this tire. I also found out that one of the rear tires has a bent rim. I have seen worse and with good balancing, it should not be an issue. Not all balancing places are equal. Some do rough work. As my friend mechanic told me there are ceratin no-no's in balancing.

One is that you never put weights across (means one weight across another), that's just plain lazy. Also there is fine tuning involved in balancing. You have to re-do it again and again to zero in on the balance. I have seen him do it on my RX. Have to take the SC to him and get my suspension checked out, too.

robertrios

iTrader: (11)

i only did my front wheels and the wheel is still shaking, should I have asked them to balance all 4? my car is an 04 w only 11k and the tires are basically new, just replaced the only wheel that could have maybe been bent.