Vibration at speed

[laush]

I seem to be getting a low pitch rumble like vibration in my 02 Outback. I had it aligned last week and the tires are only 6 months old. Any ideas ? its really annoying when you cannot exceed 105 kmh and it seems to get worse as you speed up past this. Car has only 110000 km. I checked the dif oil frt and bk. and the very rear u joint it was ok.

[bgd73]

If you know it isn't wheels. check center of driveshaft where it can bounce around. If good, you may need front half or back half. out of balance is more annoying than breaking the culprit all at once.

Wheel bearing grease can also be culprit.

[idosubaru]

has it always done this since getting the tires 6 months ago or started some time after getting the tires? i'd have the tires balanced. the place that installed them may do it for free. you can even check yourself, look at the outside and backside of each wheel and see if you can see balancing weights or a spot where there "used" to be a balancing weight. one may have fallen off. hard to tell visually because old ones may have left marks and there might not be many....but a visual check can sometimes show something. take it and they can check for you. if you've been off road or hit any potholes, any kind of hard hits like that, it's more likely to happen.

 

if you are feeling it in the "floor" so to speak then it's likely a bad ujoint. unfortuantely unless they are near failure the ujoint problems i've seen can not be diagnosed unless the driveshaft it actually removed from the car. they'll be seized, lots of slop or very lumpy....the seized and very lumpy variety failures are diffiuclt if not impossible to diagnose on the car.

 

that being said....on this new of a vehicle i'd suspect something very strange to be at work here. can't imagine a bad u-joint this soon.

[LosDiosDeVerde86]

yeah, get the tires balanced. getting into drive shafts and stuff should be a last resort.

 

btw, alignments never cause a vibration...unless it's off in a way that really chomped up the tires which in that case the tires would be at fault, not the alignment.

[laush]

I am going to take the wheels to check balance, then I will check the wheel bearings on the rear, the vibration seems to be central in the car, not more on one end than the other. If that fails I will have to remove all the heat shields to access the other U joints. One question remains though is their two weights on the rear drive shaft there seems to be a clean spot on the shaft close to the U joint at the rear dif. it looks as though at one time there was a weight there, maybe it fell off ? could this be the cause of my vibration ? I thought that maybe a way to test this would be to use a hose clamp on the shaft with some sort of weight where the spot is? any input would be much appreciated.

[nipper]

If it is central to the car, it sounds like it MAY be the center universal joint, ot carier bearing. If its the center Universal, do NOT get a price from the dealer, unless you have your heart specialist with you.

The cneter universal is not servicable, BUT it is. You need to find a driveshaft shop to send it to and they will rebuild it. When I had my 1988 GL done, and they used a ford ranger universal. Even if you have to ship it it will still be cheaper then then the sooby part. From what i understand you still have to buy the entire driveshaft, i could be wrong, but sooby doesnt change things much in the rear drivetrain

 

nipper

[LosDiosDeVerde86]

it looks as though at one time there was a weight there, maybe it fell off ? could this be the cause of my vibration ? I thought that maybe a way to test this would be to use a hose clamp on the shaft with some sort of weight where the spot is? any input would be much appreciated.

 

sounds plausible i guess

[nipper]

I am going to take the wheels to check balance, then I will check the wheel bearings on the rear, the vibration seems to be central in the car, not more on one end than the other. If that fails I will have to remove all the heat shields to access the other U joints. One question remains though is their two weights on the rear drive shaft there seems to be a clean spot on the shaft close to the U joint at the rear dif. it looks as though at one time there was a weight there, maybe it fell off ? could this be the cause of my vibration ? I thought that maybe a way to test this would be to use a hose clamp on the shaft with some sort of weight where the spot is? any input would be much appreciated.

 

Weights fall off. It is very very very rare to loose a driveshaft weight, but it does happen. If it has, you have two options. tru to guestimate the size of the weight by looking at the shadow and the other weight, or take it to driveshaft shop and let them balance it.

 

nipper

[LosDiosDeVerde86]

yeah, guessing can make it better or worse. i'd take it to someone who knows what they're doing.

[idosubaru]

i think i've noticed one weight on driveshafts before but i've never payed close attention.

 

if driveshaft balancing prices are high might be better off just sourcing a used driveshaft they can usually be found very cheap. post in the parts wanted forum here.