Soooo many vibration threads....

OK guys.....There are several things that can really cause vibration while driving. It seems as though there is a LOT of issues with these and hopefully, some of these things can help you diagnose your issues and possibly get you on the road back to happy. Remember that whenever there is a reference to raising up the car, JACK STANDS ARE NOT AN OPTION, THEY ARE AN ABSOLUTE REQUIREMENT. NEVER GET UNDERNEATH A CAR WITHOUT JACK STANDS IN CORRECT PLACEMENT AND INTERNALLY LOCKED! ! !

 

1. Tires....balance is absolutely CRITICAL and whether they are Road Force balanced is not necessarily the issue. When you go in to purchase tires somewhere or have your existing set balanced, ask for a finger mount balance rather than just letting them set them up on the center hole. Finger mount balance locates the wheel by the lug holes, which is exactly what you're riding on, and believe me it can make a difference. If you drive hard and have tape weights in your wheels, cover them with duct tape to make sure that they won't come off. If you notice a spot on a wheel where there is foamy tape and no weight, guess what? That could be your vibration.

 

2. Tires AGAIN along with wheels this time. If you purchase new tires and new wheels, mark the inside of the tire and wheel with paint before you put them on the car so that you can tell if the tire actually rotates on the wheel. This can and DOES happen and it will throw your balance off immediately. New tires and new wheels both have very slippery bead mounting surfaces and this, coupled with the mounting compound that tire shops use, makes things go on easily but leaves things slippery so the rotational slippage is absolutely possible. New tires on used wheels don't have nearly as much problem as the bead surfaces on the wheel are a bit sticky with leftover rubber from other tires and generally the tires will grab quickly after mounting, but they CAN rotate, so mark them as well.

 

3. Chassis, steering, and suspension pieces can absolutely cause inherent vibrations that will come back through the steering wheel. All of the bushings must be in good shape for all of the mounting places that require a bushing. LCA bushings must be good as this is what holds the front suspension on the car. Inner and outer tie rod ends must be in good shape as any movement within these can allow the front wheel to undulate back and forth when braking, and depending on how bad they are, even when just driving down the road. Ball joints are critical, especially in the design of Subaru's rocket scientist engineers that thought it would be a good idea to put them upside down (dorks). Raise the front of the car and check the front suspension EVERYWHERE for any movement when grabbing the tire at 12 and 6. Rear suspension bushings can also be an issue if they are seized up on critical moving parts as it will not allow your shocks and struts to work as they are designed and cause bouncing.

 

4. Shocks and struts can DEFINITELY cause vibrations but it generally is a vibration felt throughout the entire vehicle. Inspection of the shocks and struts is vital and just doing a bounce test isn't enough. Look for moisture on the boots, rust on the shafts, looseness of any of the mounting points, and listen for clunking sounds. Lift the front of the car off of the ground and have someone turn the wheels back and forth and examine the top hats closely both from the top and underneath to make sure that they turn smoothly and have no kinking or looseness. Make sure the springs are seated correctly in their respective pockets and spray a bit of lube on them where they make contact. This will ensure that they move as they're supposed to. Have someone else drive the car and listen for noises coming from the corners of the car over bumps. You can listen better when your attention is not on driving.

 

5. Hub and bearing assemblies seem to be a real sore spot on LGT and these require regular checking. They can certainly cause vibration but generally they cause more noise as they wear out. Listen closely when you drive and if there is a humming noise or rar rar rar type of noise (NO COMMENT FROM THE PEANUT GALLERY ON MY DESCRIPTION ) then you most likely have a bad or beginning to be bad wheel bearing. Fronts are easily changed but do NOT buy Chinese cheapies as you will regret it in the form of cruise control that doesn't work, ABS light on, speedometer that reads incorrectly. If you use OE Subaru, Timken, SKF, BCA, or another good brand name (Not Fred's Bearings or BillyBobBearing Co.) you'll not generally have an issue. With the front of the car raised, check for play in and out and up and down but remember that it can be a combination of many of the things listed above.

 

6. Axles can DEFINITELY cause vibrations as these rotate every second the car is moving. This applies to all 4 of the axles too. Remember, just about every single time-if you didn't have a vibration before, and you just changed an axle and now you have a vibration.........THE AXLE IS THE DAMN PROBLEM ! ! ! ...get it? Just because an axle is new does not necessarily mean that it's good. The SAFEST bet is to get OE. Sometimes that's cost prohibitive and unavailable. If you do find that you need an axle, when you purchase a replacement, buy it from a reputable parts store in your immediate area (NAPA, O'Reilly, Advance, etc.) and check it carefully before you even leave the store, let alone install it. Make sure that both ends of the CV joints move freely in all directions and that the plunge on the inner joint will move in and out without any resistance. Also make sure that the splines fit your front hub assembly correctly and snugly and if it's remanufactured, make sure that the threads on the end of the spline are in good shape. If you need help on how to change an axle, I have a thread that I posted in the Brakes and Suspension forum. Search it.

 

7. Driveshaft is overlooked a LOT when it comes to vibration because we all assume that they don't go bad, and they generally a pretty bulletproof part of Subaru drivetrain. Vibration on a rear wheel drive only car shows up and the first thing a technician is looking at is the U-joints in the drive shaft, providing he knows the rest is good. Inspect your driveshaft and grab hold of it and see if it moves at all at either end. If it does, welcome to vibration city.

 

8. Brakes are a HUGE source of vibration and of course everyone knows about a sticking caliper or seized caliper and how they turn the rotor blue, eat your expensive brake pads, and stink like hell when you stop. Make sure that EVERY single part of your braking system is in perfect working order. Do maintenance on them yearly. Disassemble them and clean them and lubricate them and paint them and chant at them and kneel down and beg at them. If you are absolutely sure that your calipers are all in working order as they should be, then of course, there's the rotors. These can warp but generally most issues arise from improper bedding of the pads in the first place. BED THE PADS BABYCAKES ! ! There are a number of threads on here on the proper procedures to bed the pads. FOLLOW THEM TO THE LETTER ! If there is still vibration in your brake pedal after or vibration and everything above is good, then perhaps you do have bad rotors. The other sticking point on brakes that most people don't realize is the emergency brake inside of the rear drurotor (drum/rotor) and these can also stick and grab, making the rears hot and stink and stick. Make sure that your E-brake works and is releasing all the way.

 

OK....enough for now. I've errands to run but I'll be back later on tonight and add some more stuff. Many if not most of you know all of the above stuff already but sometimes it's good to get things out so that maybe it slipped your mind or you ASS-U-MEd that it was OK without actually checking it. Don't discount clutch related, automatic transmission, and driveability issues either. These can all cause vibrations in your car.

 

Hope these help someone out there to find their problem. I'll post more later on.

Good stuff dude.

All rotation needs balance.

Good stuff dude.

All rotation needs balance.

 

Thanks much. I'm surprised that no one has commented or asked any questions about this thread. I guess it must just look like "Another vibration in my car" thread....LOL..

Good stuff. Valuable info. Hope you guys can help me. I have an 08LGT and for a while now I get a vibration only between 40 and 60mph. Any gear, any rpm, the vibration comes and as soon as I get past 60 it stops. At first it just sounded like wind noise from by the windshield. But as time went by I started feeling some vibration in the pedals and the noise has gotten worse. I had the tires balanced twice already. I get a little squeak in the brakes especially when its still cold, but it stops fine and no vibration when I'm braking. Just bought it a few months ago so not sure how old the rotors or pads are. Any help appreciated. This sound is annoying!!!

………………………………………………….

1. Tires....balance is absolutely CRITICAL and whether they are Road Force balanced is not necessarily the issue. When you go in to purchase tires somewhere or have your existing set balanced, ask for a finger mount balance rather than just letting them set them up on the center hole. Finger mount balance locates the wheel by the lug holes, which is exactly what you're riding on, and believe me it can make a difference. If you drive hard and have tape weights in your wheels, cover them with duct tape to make sure that they won't come off. If you notice a spot on a wheel where there is foamy tape and no weight, guess what? That could be your vibration.

 

2. Tires AGAIN along with wheels this time. If you purchase new tires and new wheels, mark the inside of the tire and wheel with paint before you put them on the car so that you can tell if the tire actually rotates on the wheel. This can and DOES happen and it will throw your balance off immediately. New tires and new wheels both have very slippery bead mounting surfaces and this, coupled with the mounting compound that tire shops use, makes things go on easily but leaves things slippery so the rotational slippage is absolutely possible. New tires on used wheels don't have nearly as much problem as the bead surfaces on the wheel are a bit sticky with leftover rubber from other tires and generally the tires will grab quickly after mounting, but they CAN rotate, so mark them as well.

 

Since most Legacy wheels will be hub centric instead of lug centric, why do we need a finger mount balance?

 

Another potential source of tire vibration is imperfect tire bead seating, from under use of tire lube during mounting.

 

From Hunter Engineering:

……………...“Lube is Good!” Proper lubrication on the tire bead AND rim areas including bead seat, hump, balcony, and drop center are vital in achieving proper seating of the tire bead to the wheel assembly. Aggressive acceleration or braking should be avoided for the first 500 miles to prevent tire to wheel slippage…………….."

Funny I just found this.

 

One of todays chair lift topics amongest us Subaru owners was a buddies 2005 Outback XT. Somewhere around 90,000 miles, it started to have the lug nuts get loose. After the dealer checked it out and tighten the lugs, it was fine for a while.

I recall him talking about a broken wheel stud last winter. I'm guessing around 110,000 miles.

 

Well this summer after a couple of long drivers on the highway, (car has 125,000)the next morning on the 5 mile drive to his office the steering wheel was shaking. He found the lug nuts on the the fronts were loose. He gets the lug wrench and tightens them and two break off.

 

They had the studs replaced at the dealership, then a short while later traded the car in for a 2014 Outback.

 

The mechanic meantioned that they see a few of that Gen. outbacks with this problem every year.

 

 

 

FWIW, since the lug studs on my 98 Legacy were rusting and the threads needed a die run over them, I have been putting anti-sieze compound on all the threads of the lug nuts and stud of every car I change wheels on.

 

I have have had a lug stud issue since.

Since most Legacy wheels will be hub centric instead of lug centric, why do we need a finger mount balance?

 

Another potential source of tire vibration is imperfect tire bead seating, from under use of tire lube during mounting.

 

From Hunter Engineering:

……………...“Lube is Good!” Proper lubrication on the tire bead AND rim areas including bead seat, hump, balcony, and drop center are vital in achieving proper seating of the tire bead to the wheel assembly. Aggressive acceleration or braking should be avoided for the first 500 miles to prevent tire to wheel slippage…………….."

 

Finger balance is the absolute best way to ensure that your wheels are balanced on the plane that they ride on when mounted to your car even if the wheels are hub centric. Most shops have the fixtures for finger balancing but they don't like to do it because it takes longer to set up the wheels and balancer, but you'll definitely feel a difference.

 

If you want to test for yourself, take your car in, even if it seems to ride OK, and have them rebalanced using finger balance, and in most cases, you'll definitely feel the difference.

More from Hunter:

 

"…………..Tire technology is always changing. Today's vehicles require the tire to be designed to tightly adhere to the wheel, preventing slippage between the two components. As a result incorrect tire bead seating procedures are becoming more of an issue in solving vibration complaints. In many cases, a wheel will display high non-uniformity values because of increased tire bead interference, wheel design or improper bead seating procedures. If the tire is re-loosened from the wheel and properly lubricated and remounted, the level of non-uniformity may decrease dramatically. On sensitive vehicles, sometimes there is benefit to slightly over-inflating the tire, deflating the air, and then re-inflating to optimize bead seating………………."

 

http://www.gsp9700.com/technical/4458T/4458T.htm

"Finger Balance" never knew, good stuff thx John

……….Ball joints are critical, especially in the design of Subaru's rocket scientist engineers that thought it would be a good idea to put them upside down (dorks). ………………….

 

Why are upside down ball joints a bad idea?

……….Most shops have the fixtures for finger balancing but they don't like to do it because it takes longer to set up the wheels and balancer, but you'll definitely feel a difference………..

 

Adapters like these: ?

 

http://www.haweka.com/en/index.php?nav=5.79.83.103

Putting a steel ball joint into a cast iron steering knuckle makes them do exactly what we all know they do-RUST SOLIDLY IN PLACE. Putting them in upside down with a way for water and salt and road acids to get in there is even more stupid. Because of this asinine decision, how many bolts are broken off from people trying to remove the BJ from the knuckle? How many people have had to remove the entire knuckle in order to have a shop knock them out?

 

If the ball joint had been mounted on the LCA with the stud pointing up and through the bottom of the knuckle and simply a nut on the knuckle, there would be much less issues with changing it, much less issues with getting it loose. Had it been done this way, all LCA bushings and BJ at once would have been easily accomplished in just a few hours.

FWIW, since the lug studs on my 98 Legacy were rusting and the threads needed a die run over them, I have been putting anti-sieze compound on all the threads of the lug nuts and stud of every car I change wheels on.

 

FSM calls for 81.1 ft-lbs torque on the lug nuts (I think). What do you torque them to with anti-seize on them?

 

I know you're supposed to lower it but I don't know by how much.

 

Are the studs fairly easy to replace?

FSM calls for 81.1 ft-lbs torque on the lug nuts (I think). What do you torque them to with anti-seize on them?

 

I know you're supposed to lower it but I don't know by how much….

 

get the data sheet for the anti seize you are using, it should have a K value (e.g 0.18) listed in the specs. K value is the "nut factor", lets call it Kas. You also need to know the K value for the unlubricated OE nut and stud (good luck with finding that!), lets call it Koe.

 

(Kas ÷ Koe) x 81.1 = new torque value

I replaced the z tires with some H tires. They look like they have more height, but the numbers are the same. Anyway, it drove like a dream for 5 miles. yay!! I cleaned it up and serviced it, then took it out for 50 miles of errands. Rear Left Wheel vibration. !!!

it only happens on Deceleration, and is particularly louder and more pronounced on a right turn. Left turn it quites down. Apply the emergency brake, and it quiets. I am going to have to tear into while I listen to the INDY 500. GO MARCO, Scott Dixon, Tony Kanaan,

Can someone sticky this?