wheel hub center cap- damage when balancing

[edwardh1]

I have an infiniti with alloy wheels, 5 lug nuts of course, and a center ornament (anout 2 1/2 inched in diameter) that evidently comes off- when the tires were last balanced the tire place said the center ornament finger that hold it on had broken and could not be put back on.
I did not even know the ornament came off. \
when they balance the tire does part of the machine poke thru the center hole, is that why they have to take it off/out?

 

[eljefino]

Yes it does. A trap for the rookie tire tech is that most steelies and "some" alloys don't even have a cap there, or the cap comes off before the lug nuts.

Typically your "speed lane" dolt swings the 45 lb assembly onto the balancer, letting the balancer's axle poke the center cap out. If yours has a dozen spring loaded tab-fingers, you may have had six removed in a previous altercation, and "precious few" remaining for the unlucky guy who busted the final tab.

Long story short, get on that tire store if this matters to you.

In the picture below, the balancer has an axle that goes through the center hub hole. A cone centers it on the axle, and a large wingnut cinches everything tight on the cone so it's centered mostly well.

Fun fact, those cones get wear spots in common diameters and this can lead to errors balancing.

 

[geeman789]

Yes. The part is called the center cap. Most are plastic... If you are very careful with them, they will last forever. If you are in a rush, hint hint tire shop... they are very easy to break... the shop should be replacing it if THEY broke it. They are usually about $ 10 to $ 20 , but it varies brand to brand.

After 7 years of wheel swaps, I broke my first cap.. about 30 cap swaps if I were to guess. The little snap tabs get brittle after awhile.

 

[Chris142]

Every time i go to americas tire they bend up my rings. They already lost all 5 of my center caps

 

[edwardh1]

almost like u need to take them off yourself with a screwdriver before u go to the tire shop.
my car has 140,000 miles, 6k rotations so what 20+ rotations??

 

[edwardh1]

Originally Posted By: eljefino
Yes it does. A trap for the rookie tire tech is that most steelies and "some" alloys don't even have a cap there, or the cap comes off before the lug nuts.

Typically your "speed lane" dolt swings the 45 lb assembly onto the balancer, letting the balancer's axle poke the center cap out. If yours has a dozen spring loaded tab-fingers, you may have had six removed in a previous altercation, and "precious few" remaining for the unlucky guy who busted the final tab.

Long story short, get on that tire store if this matters to you.

In the picture below, the balancer has an axle that goes through the center hub hole. A cone centers it on the axle, and a large wingnut cinches everything tight on the cone so it's centered mostly well.

Fun fact, those cones get wear spots in common diameters and this can lead to errors balancing.

------

how often and how are the machines calibrated.

 

[eljefino]

Originally Posted By: edwardh1

how often and how are the machines calibrated.


The biggest miscalibration I've seen is in the *amplitude* of weight needed. Zero/balanced indicated remains balanced.

So it might read out you need 2 oz when you need 1.75, but if the operator puts weight on and spins again it should read zero. Overkill would be to remove the wheel, spin it 90 degrees relative to its former position, and re-spin it to check balance.

 

[CapriRacer]

Originally Posted By: edwardh1
how often and how are the machines calibrated.


They are calibrated when the shop wants to. Sometimes they have a regular program, but most times, not.

How do they calibrate? There are quite a few different ways.

A simple way is to bring a known good tire and wheel assembly, then add weights to see the results.

 

[SwampSurvivor]

Originally Posted By: edwardh1
almost like u need to take them off yourself with a screwdriver before u go to the tire shop.
my car has 140,000 miles, 6k rotations so what 20+ rotations??


I do. Whenever I bring a tire/wheel to be mounted and balanced, I remove the center cap / hub cap.