6SpeedOnline - Porsche Forum and Luxury Car Resource

6SpeedOnline - Porsche Forum and Luxury Car Resource (https://www.6speedonline.com/forums/)
-   991 (https://www.6speedonline.com/forums/991-145/)
-   -   Wheel out of round....? (https://www.6speedonline.com/forums/991/420560-wheel-out-round.html)

drspeed 05-16-2018 10:21 AM

Wheel out of round....?
 
I’ve driven my 911s over 100k miles on road & track and never had an issue with a bent wheel - until now.

when the dealer installed Michelin PS4s a few weeks ago, I noticed a slight vibration at 90-100 but more troublesome is a low bass reverberation that accompanies the slight vibration.

Tech said one wheel was going up an down a bit as they spun it to balance. So I had a wheel shop repair that one wheel. Problem is better - but still there.

wondering if anyone has gone through this before? Wondering if the tires have any role in this. There was no problem with the winter tires on the same wheels??

I’d have bought a new wheel already, but it seems like a rip off. Porsche sells a full set of wheels, w/pressure sensors, center caps and tires for $6500, but one wheel is $2,400.00?

The repair guy said is was out about 40/1000ths to start and he got it down to 13 supposedly.

Just curious to hear any feedback. Thanks.

DRP



90sundevil 05-16-2018 11:29 AM

I currently have one rim that is a little out of round on my Cayenne that only exhibits some shaking around 50-70 and nothing higher or lower. If the car was younger and had less miles I would deal with it but just going to live with it until I wear out the tires I currently have on the car. Now if any of the prior couple dozen 911 I have owned had that problem I would fix it right away even if it meant replacing a rim.

solrac6262 05-17-2018 11:35 PM

did you hit a pothole or something ? why the wheel had to be repaired? if the wheel was ok then its your tire or the guy that mounted the tire, did you do RF balanced?

dbh 05-18-2018 10:55 AM

Wheels and tires generally come from the manufacturer with some imbalance. If the installer can maneuver the imbalance on the tire to offset the imbalance on the wheel he can reduce or eliminate any imbalance on the tire/wheel combination.

The wheel shop did a pretty good job. It is nearly impossible to true a wheel to 100%. Try having the wheel/tire rebalance by a high quality specialty shop.

Winter tires tend to be much more compliant and will cover up some wheel imbalance, whereas the summer performance tires will not - if anything they'll amplify it.

solrac6262 05-18-2018 11:01 AM


Originally Posted by dbh (Post 4716404)
Wheels and tires generally come from the manufacturer with some imbalance. If the installer can maneuver the imbalance on the tire to offset the imbalance on the wheel he can reduce or eliminate any imbalance on the tire/wheel combination.

The wheel shop did a pretty good job. It is nearly impossible to true a wheel to 100%. Try having the wheel/tire rebalance by a high quality specialty shop.

Winter tires tend to be much more compliant and will cover up some wheel imbalance, whereas the summer performance tires will not - if anything they'll amplify it.

on the xxxx times I had changed wheels and tires never had issues, dealer always does a good job with the RF machine, only time it was last month with my RRS I replaced a tire, the guy that did the "Road Force" put like 18 weights on one side and I went back and Complaint to re balanced or get a new tire if it was out of round, they did re balanced and need it less weight, everything perfect

drspeed 05-18-2018 02:36 PM

vibration
 
I had the local Porsche independent shop rebalance the wheels. There is no vibration, but there is still a little hum from the tires at 88-95.

I'm going to have my old P Zeros put back on just to see if that vibey resonance persists. If it disappears with the Pirellis, I'm contacting Michelin ASAP.

Its Pirelli that is known to have balancing issues. Michelins have always been superior in every way in my experience.

I'll post the results after I swap back over. This is a PITA.

Thanks for the replies.


DRP

solrac6262 05-18-2018 02:40 PM

is the noise real bad? lol you are driving too fast are those numbers Freeway? I can't stand Pirelli's they are noisy, Michelins PSS are way better tire, personal preference

dbh 05-18-2018 03:02 PM

I've had both Pirelli and Michelin tires. I don't recall any high speed hum from either brand. The Pirelli tires did get LOUD as they wore, becoming almost unbearable toward the end of their life span. Haven't gotten that far with the Michelins yet. Not sure I'd switch back to the Pirellis just to do a comparison. But then again, I don't spend a lot of time listening for tire hum at 90+ mph. :rolleyes:

drspeed 05-18-2018 03:09 PM

I know...I know...
 

Originally Posted by dbh (Post 4716479)
I've had both Pirelli and Michelin tires. I don't recall any high speed hum from either brand. The Pirelli tires did get LOUD as they wore, becoming almost unbearable toward the end of their life span. Haven't gotten that far with the Michelins yet. Not sure I'd switch back to the Pirellis just to do a comparison. But then again, I don't spend a lot of time listening for tire hum at 90+ mph. :rolleyes:

I know, tire noise at 90 is not something most 911 drivers would complain about. But this is my DD. The 991 in 7th on the highway is a limousine compared to any 911 with 6 cogs or less. my 997 was at 4500 rpms at 90. A whole lot of everything going on. Not so with the 991.

In any event, the noise is not "supposed" to be there - and I know that, so that part it bugs me too.

I had no problems with Pilot Sports, PS2s, Super Sports on prior cars, but these 4Ss have not won me over yet. They grip like glue, but they don't have that indescribable michelin precision I have come to know and love.

We'll see what happens with the P Zeros back on.

DRP

dbh 05-18-2018 03:39 PM

Just a thought - are the tires mounted with the "outside" on the outside?? It happens! :eek:


All times are GMT -6. The time now is 03:54 PM.


© 2024 MH Sub I, LLC dba Internet Brands