Fuchs balancing issue?!?!

Skip Newsom · 02-29-2008, 03:43 PM

I did a search and did not see any posts that delt directly with what I'm faced with...
I bought some new 205/60/15 Michelin Pilots for my 72 911 Targa from tire rack a couple of weeks ago and just got around to getting them mounted today. (Off the car, I don't let anyone but John Walker touch my car!)

What surprised me was what the Goodyear tire center told me went I went to pick up my wheels and tires, they said that three of the 4 were "way out of whack".
They said that my beloved original 6" Fuchs needed as much as 4 ounces of weight to balance them and that with that much weight I'd likely feel vibration anyway.

I replaced the old tires(not knowing how old they were at the time) with some Yokohama's when I bought the car 5 years ago and I don't remember anything about excessive weight needed at that time to get them in balance.

There does not seem to be any run out and they ran nice and smooth with the Yoko's on the car up to this point.
Looking at where the old weights were, it does not look like it had that much on them before... and no, I have not hit any potholes, slammed a curb or done any jumping with the car.

Here's what I think my next move should be:
Take them to some one with a Hunter road force balance machine to see what they say...

Anyone else run into this kind of situation?

How much balancing weight is too much?

Jim727 · 02-29-2008, 04:00 PM

You probably need a tire shop run by someone with grey hair.

I have a '71 so we probably have the same issue. I'll bet the tire shop tossed the wheel onto a balancing spindle that ran through the center of the wheel. On the older Fuchs, that center hole is not exactly centered, and the wheel is meant to be balanced when mounted on the wheel studs.

Find someone who can mount the wheels correctly and I'll bet your "problem" wheels are just fine. Also, when I had Harvey Wiedman restore my wheels he trued up the center holes to compensate for shops that can't/don't know how to balance the old wheels correctly.

Jim

zzwhm · 02-29-2008, 04:06 PM

Skip -
You can have your Fuch wheels trued. A shop that does this will check them first and let you know in advance how out of whack they may be, and if they're not then it's the tires. Here in DFW it costs about $75 per wheel.
Bill

zzwhm · 02-29-2008, 04:08 PM

And +1 on what Jim says about spindle versus studs.

cgarr · cgarr's Garage

I am surprised they didn't break down the tire and turn it 180 and check it again, sometimes you have to do that with rubber thats way off..

J Smith · 02-29-2008, 04:32 PM

Why do you think it's the wheels? Tirerack has been known to send out tires that have been sitting around the warehouse for years (a good tire guy can read the code on the sidewall and tell you when they were produced). And even if they're relatively new, there's no guarantee they're not out of whack.

And IMO, road force balancing is overrated and unnecessary.

porschenut · 02-29-2008, 04:42 PM

Goodyear, Firestone and all the rest want you to buy the tires from THEM. My hunch tells me they're blowing smoke. These places have tried to rip me off more than once. Once, I brought my car (not Porsche) to Sears Automotive for brake pads. They called back and told me that my "calipers have failed" and "need to be replaced". Of course, there was nothing wrong with them at all.

Stay away from those places. Take your wheels/tires to a Porsche indy place that you trust. They can mount/balance properly for you and probably will treat your Fuchs wheels with a lot more care.

gtihop · gtihop's Garage

first of all, where did they put the weights? If on just the inside lip on one side, then they are static balanced and it will generally require more weight. If they put the weights on both the inside lip and also on the other side just behind the face of the rim then they should take less and will be balanced better. If the tires are round and the rims are round, then turn the tire on the rim 180 degrees and try to rebalance. This usually solves an excessive weight problem. I did my rears on just the inside and they took 3 oz and have no vibration.

rusnak · 02-29-2008, 05:00 PM

Jim, that is a fascinating fact.

How about the 7" and 9" Fuchs? Are they centered around the center hole?

I have had Yokohamas that were way out of balance. Michelins and newer Bridgestones have been much more balanced in my experience.

Jim727 · 02-29-2008, 05:07 PM

rusnak -

Don't know about other wheels. Mine are 15" 6 and 7R, and Harvey Wiedman filled me in on the issue and I have no reason do doubt him. Certainly explained tire balance issues I had in the past.

Yokos are not the tires they once were, apparently. Michelin still has high production standards and I've never had a problem with them, but my tire shop had to swap one of my new yokos because it was out-of-round. Unfortunately, Michelin doesn't have a 205/60 and 215/60 for my 15" wheels.

Eagledriver · 02-29-2008, 05:16 PM

Have you driven the car? Maybe you don't have a problem.

The center hole on all my Fuchs are machined into the center of the wheel. They are perfect. I've had more trouble when someone tried to balance my tires on the lugs using an adapter plate they had than with the wheels mounted by the center hole. 4oz is not excessive. Make sure they do a dynamic balance on the front wheels (this takes more weight, not less). A dynamic balance is one that not only balances the wheel around it's center of rotation, it also balances it such that it doesn't try to "wobble" due to the mass on one half being outside or inside the mass of the other half.

The rears are ok with just a static balance. The front of a 911 is very sensitive to wheel balance.

-Andy

billybek · billybek's Garage

I was amazed at the amount of adhesive from weights that had been removed still on my wheels. I think I will strip everything off and start from scratch.
I question the balance on mine as well.

WolfeMacleod · 02-29-2008, 05:42 PM

By any chance was that the Goodyear shop in Lynnwood, right near the Discont Tire place on 196th?

If so...I had the same problem with them. That place SUCKS!

hcoles · 02-29-2008, 05:44 PM

see if you can get them to rebalance while you watch... on some balance machines they have to turn the wheels around and use a different tool to find the center on the hub. The Fuchs should run true to about a total runout of under 0.010 inches. You can see when the machine spins them the wheel part and the tire should show very little signs of being out of round.

Skip Newsom · 02-29-2008, 07:22 PM

Thanks for all the replies!

Cgarr, My bet is that they did not even bother; I think Porschenut has them dialed in.

Jsmith, I have always had very good luck with Michelins and these were made recently, you are absolutely right though... could be the tires.

Porschenut, that's kind of what I suspect...

GTIhop, They stuck the weights all on the inside of the wheel very close to the inside edge.

Wolfe, It was the shop next to the Everett mall... I won't return.

Eagledriver, I have not put the wheels on and driven it yet, I really want to be sure the tire/wheel is balanced correctly first.

Tomorrow I'll start calling around to see who has a decent balancer and ask how they mount wheels when they balance them... It will be interesting to see if they say a bunch of weights need to come off.

My Yoko's were down to the wear indicators; I'm excited to have new shoes on the old girl again!

barney911rs · barney911rs's Garage

I like Craig's suggestion of dismounting the tire and rotating it around on the rim before doing anything drastic. I've never had a problem getting my Fuchs balanced using the center hole, as long as the "tech" made sure to use the correct adapter to hold the wheel correctly on the machine.

I have never seen a balancer that uses the stud holes. How would you account for all the different stud sizes and spacing, not to mention 4 vs 5 bolts or even more on some big trucks??

kees · 03-01-2008, 12:00 AM

Quote:

Originally Posted by barney911rs

I have never seen a balancer that uses the stud holes. How would you account for all the different stud sizes and spacing, not to mention 4 vs 5 bolts or even more on some big trucks??

I think he means "balancing while the wheels are on the car".

Kees.

barney911rs · barney911rs's Garage

That I have seen. You'll be lucky if you can find a place that still does that.

hcoles · 03-01-2008, 06:04 AM

this is the way I would approach the problem:
1 - the Fuchs should be true - you can check this on the car, mount and spin by hand
2 - if not true then that needs to be fixed or get a replacement
3 - the balance machine needs to grab the wheel so it spins true like when it was mounted on your car - using the center hole should work fine for this
4 - when spinning the wheel should look true and the outside of the tire should be true...maybe something under 1/16 inch. You may have some flat spots... so look out for those.. heat the tires up on the car can then quickly take off and go down to the tire shop
5 - I suggest putting the weights on with about 3/4" space to the rim turn - this gives room to put some high quality "duct"/"duck" tape to hold the weights on.

moneymanager · 03-01-2008, 06:40 AM

I guess I don't understand the problem. Is there a performance issue? Front end shimmy? I just happen to have had four wheels (for a 73 911) balanced by a polisher. There was shimmy at 65mph. Then took them to my local guy who has a Hunter Road Force. He redid them, adding 1/4 oz to each. They are now perfect. Two of the wheels have 3+ ounces of weight, one has less, and one has 5 +. I don't see why you care how much weight you are carrying, within reason. Either they are perfectly balanced or they are not... BTW, my experience over the past ten years and about 20 sets of tires suggests that that Hunter machine is the key to everything...search on the Hunter site for a local guy who has it. fwiw.