O.K. so at 85MPH in a straight line going over a few small rollng dips in the road, I can feel a high speed vibration when the coil springs are close to there maximum compression.
While making a long left turn at high speed such as a hiway interchange or something the vibration gets worse. Not so much turning to the right mostly to the left. Almost like if there was alot of pressure on the right front corner of the 850. The wheels are balanced and the car drive straight as an arrow. Could it be wheelbearings on the right front side? According to my parts guy the wheel bearings come only in a pre assembled hub. Maybe its an axel problem. What do ya'll think?

 

Hello Mr. nottacop,

At this moment I am not sure what is causing the vibration. Even if the car runs straight like an arrow, an out-of-spec alignment sometimes shows up at certain conditions, especially the rear, though this probably doesn't have anything to do with your problem.

Do you hear any noise, when driving over bumps? It may be due to worn out upper spring seat, upper strut mount, ball joint, loose locknut(s), etc... If it was the worn out hub, you probably would hear some noise even at different (slower) speed. I would first visually inspectsuspension componentsfor wear/damage with the wheel off, then try to see if there is free play somewhere by trying to move things around. Are the brake components, especially the right-side rotor, all right?

Asfor the front wheel bearing (hub), yes it is a self-contained unit and the entire hub needs to be replaced.

http://www.volvospeed.com/Repair/FWDbearingHub.php

Any additional info will help narrow down the problem.

Best wishes,


JPN

 

Great link JPN this was so informative. I will have no problem doing this soon. I will take the wheel off this weekend and check the parts you suggested. I'll let you know what I come up with. Thank you, Notta...

 

Are the tire out of round?
Are the Axle boots torn and leaking grease?

 

Funny you should metion the tire thing. The boots are fine and there is no grease leaking from anywhere. I have 225/50/15's on there I believe. I went with the wider size for looks. They should be like 1 cm or a half inch wider. Same height just wider. I was tinkering with the car the other day and thought to lift the right front wheel, start it up, put the emergency brake on full, put it in drive and take my foot off the brake. By now the front right wheel was spinning in idle. Don't try this at home kids. I took the floor jack handle and put it up to the spinning wheel as if to measure it from the ground up. The wheel was dead on and has no hop to it but the tire itself had about a 1/4 inch hop to it. Suprised, I did this to the other tires and it seemed they were all out of round. Is this common? Someone told me that it was common and that under load it wouldn't make a difference. The tires were or are Pep boys brand Futura GLH. Let me know what ya'll think. I just called them before I got home to ask there hour to take it in and have what I discribed above out.

 

Hello again,

Asfor the tyres:

>The tires were or are Pep boys brand Futura GLH.

I personally avoid cheap/generic tyres, as the performance is greatly affected by choosinglesser-grade tyres. My 850 has Yokohama A550V and they are excellent tyres.

>Someone told me that it was common and that under load it wouldn't make a difference.

↑Was he/she a master ASE certified? I wonder. Wait till Mr. Tech replies again. As far as I know, tyres have to "warm up" to exhibit maximum performance. This means you'd have to drive the car at least for a few miles, depending on the weather.

If all tyres where showing the same habit, it probably isn't the cause of the vibration.

Good day,


JPN

 

If it had a pretty good hop to it then they are out of round.
You could balance them to the cows come home but still have a vibration.

If the rears look better then swap front to rear and see if it is better.

 

Swapped right front for left back. Helped alot but still has a slight vibration. Mycertified mechanic suggested that it might be the hub. There is no noise coming out of it so I dunno. I'll keep poking aroud. At least I got it down to a dull roar. Thanks guys for your help, Notta...

 

I'd have the tires balanced at a place that can do 'road force'. The new line of Hunter balancers (within the last 2 years) can give you a road force analysis on the tire wheel combo and tell you if you have a slightly bent rim or a tire out of round. In doing so, the mounter can move the tireon the rim to give the least amount of vibration, but in most cases, anything over a '50' rating is going to be a bent rim or a tire quitea bit out of round.

Another thing to consider is that when a tire sits for more than 20 minutes, it creates a temporary 'flat spot' until the tire is run and warmed up, thus making it 'round' again. Depending on sidewall stiffness, this can be very noticable. With the Hoosier R compounds I used to run back about 3 years ago (SCCA autocross), I had to park the car and put it up on jackstands for the night, or drive it for 10-15 minutes to get the tires round again, for they didn't have any steel belts at all (fiberglass).

A wheel bearing to me would be noticable at all speeds, and tend to groan when turning to one side or another when it starts to fail. - AB

 

Agreed have a really good balance done.
Also swap the other 2 and see if it gets even better.