vibration at certain speeds
 

I have mentioned this as a response to another post but that was many many months ago and I was hoping people have new ideas or even solved their problem...

What would cause a vibration in the seats (not steering wheel) when accelerating or even coasting down between 55-70mph? Anything higher or lower and it's smooth again. I have had them balance 2 times (there are weights on the rims) and did a wheel alignment (to make sure) as well... problem remains, on different roads so I know it's not just a stretch of highway, etc. This does not occur at any other vehicle speed. Number of passengers doesn't matter either. I can actually see the seat vibrate too.

From the old thread it looks like I'm not alone on this issue. I have replica wheels which were spun to ensure they were not out-of-round on Toyo Proxes S/T. They are at 36psi (would different tire pressures cause this at certain speeds only?)... I ask because this used to happen at a different range (70-75mph only). The stock 19s never had this problem.

**EDIT 11/4: see resolution below.

Strictly fwiw, the ol'Conventional Wisdom suggested that feeling it in the seats
was due to rear wheel situ.
Another spin for the rears may show one or more out of round, with a slight bent rim, etc.
GL,mD

Rh71,

I suggest you mount your stock 19s at the back and check if the problem goes away. From what you describe, it looks like it is a problem at the back and not the front since your steering wheel does not vibrate. It should not take you long to swap them back and forth.

Let me know what you find out.

You could have them road forced balanced.

+1

The 19s are already sold. I will have to get them road-force balanced at the dealer then. I asked to have this done last time but they wanted me to at least get the wheel alignment first because that was probably never done at my independent installer. The stealer's alignment & balancing aren't cheap at over $150 each service - and I wasn't willing to spend over $300 just for a "maybe it may fix it" so that's why I'm posting again here. I suppose it irritates me enough to want to get this done properly this time. I want to have them take care of this since they are supposed to be held to higher standards than an indy shop... am I wrong?

what do you guys think of this person's response at another board? Seems he's saying this is somewhat expected.

I still vote for my orig. hypothesis of a rear wheel(s) way off balance, out of round and/or a bend in one...
Edit: PS...in the time it takes to fiddle with tire pressures, (done when tire is "cold", no less), one can
be down at a quality tire joint and have it diagnosed.

^ I'm just a bit wary of taking it to a regular tire shop... if they (Mavis discount tires) treated my mint-condition Isuzu like a POS (dented the door) I don't want to think about what they do with nicer cars (including joy rides). Do you guys bring it to Joe Schmoe tire shops? What's really considered a quality tire shop? I trusted that independent shop that specializes in rims & tires and they couldn't get it right to begin with. I wasn't about to bring it back to them a 3rd time.

I guess what I'm asking is... should I pay the dealer their asking price as opposed to doing it somewhere less reputable but cheaper for a supposedly simple job like this?

Long Island: big place. There has to be a decent tire specialist joint in your area. Maybe some fellow poster from your zip will rec'd one...no, I doubt many of us go to cheapazz tire joints.

Try GOOG, Yahoo Yellow Pages, et al.
Easy stuff, imo.

I believe some of his points make sense, but the outside temperature will play a role here too. Here in Denver, during Spring the temperature during the day can reach 85 and can drop to 35 at night. I live in New York and I know you may have some drastic temperatures changes too. Therefore it will be impossible to really draw a conclusion from this experiment. My suggestion: take the car to the stealer and take care of the alignment/balancing.

When the dealer does an alignment on a BMW, don't they use sand bags to weigh the car down? I don't think any regular shop has the bags. I also think the alignment specs are different for the 20" wheels.

Any shop with a road force machine should be able to balance your wheels. For the alignment, I would stick with a BMW dealer...

Craig

Agree with Craig..

Have the wheel balance done using a Hunter Roadforce wheel balancing machine. It makes a big difference, especially so on big wheels. You can find a place in your area that has this machine using the Hunter site (brings up car dealers too):
Hunter GSP9700 Wheel Vibration Control System

Have the alignment done at the dealer. It doesn't cost much more (if anything) than at a generic place.

So I took it to a Goodyear shop that was listed as having a Hunter machine... which charged $30/tire (which is avg by calling around). First did the 2 rears - since the vibration is in the seats, visible shaking too)... and the vibration was still there, a little worse perhaps. Then I had them do the 2 fronts and while it's better, it is still pretty consistent when accelerating through 60mph and upward. It is also there when letting off the gas (no brake) from 80->60mph.

The shop just calibrated their machine yesterday so it's supposed to be really accurate. He put weights in different places (some needed more than others, said it was really off before)... and all 4 tires are now spinning perfectly round, the rims are not out-of-round and the tires look good.

Ideas? I can bring it to the dealer and state the same problem, state they were road-forced, but they will probably ask me to pay their fee to do it again at a much higher price (and still may not fix the problem). I already did a wheel alignment through them. Suspension isn't likely to cause this right?

*UPDATE* I spoke with the company that sells the rims (wheelsandcaps) - they say the vehicle won't even accept hub centric rings and their wheels don't require them. We had a good 5-10 min conversation and he was pretty knowledgeable so it wasn't like he was trying to squirm out of responsibility. He couldn't do anything for me after a year of use anyway. He thinks the guys never actually did the road-force, which usually accounts for up to 120mph. All I saw was a spinning wheel and unsure if anything was pressed against it from my angle. He thinks it's the actual Toyo tires that are bad because when a store gets a new rim they are supposed to spin the rim... 2 places have confirmed the rims are not out-of-round.

If you're getting vibration on acceleration/deceleration that's worn cv joints.

Hmm, the car has 6k mi., less when this started. Would that cause a creaking noise going up/down driveways (front and back wheels) like I've been experiencing too? It's weird how the vibration started immediately after I got the new wheels/tires on last year though. Could they have been damaged during the install - are they even close to each other?

I wouldn't think wheels would damage the joints. Have you taken it to the dealer? If it's under warranty let them diagnose the problem.

I've found that using the hub centric (the center of the wheel) to balance the wheel isn't very accurate (hunter or not) especially larger rims. I tried to balance an previous set (22") on a previous vehicle and the only way they were done correctly was by using a balancer that mounts to the wheel lugs (the way it fastens to the car).

Just wanted to update that my vibration is gone after replacing:
1) left rear warped rim - still had some vibration after, but it was definitely less
2) right rear toyo proxes ST tire

They gave me remaining-life credit (8/32 & 9/32) on all 4 so I got a new set of Proxes ST II for $250 plus taxes/mount/balance. Couldn't just replace the one since the STs are discontinued in the 315/35/20.

Right away I noticed the steering is lighter. Just glad the problem is gone and I can drive at highway speeds with a smile again. If anyone's interested, I can do a Proxes STII long-term review at some point. All dealers were really negative about the STs in comparison.

BTW, nobody go to AutoTrend in Lindenhurst, NY (also on ebay as 1015f). They sold me the out of round Toyo tire, I brought it back to them twice and they wouldn't admit to the problem. It was an easy warranty claim from Toyo but they chose not to do it. STS Tire immediately saw the hop when being spun on the balancer and did the claim for me. I've spent $500 more than I had to over these months to resolve this whole thing all because they were not honest with me about balance results from the beginning.

Another tip about balancing, ask what speed the balancer spins the wheels up to, because it makes a difference. You do not need road-force balancing to get it right. When I had that done it only went up to 25mph and the vibe was still there at 65. That was a waste of $135.