Repair of Car Rims

[chicopee]

With vintage cars early 70's having wobbling rims during dynamic balancing, can these rims be straighten out since new rims would no longer be in production

 

[MikeHalloran]

Don't just assume that you can't get new rims; many are still produced.
... but there are people who repair rims for a living,
and have stayed in business doing it.

First check that bearings are okay, and hub seating surfaces are clean.
Second check hub face runout with a dial indicator.
Then start checking the rims.


Mike Halloran
Pembroke Pines, FL, USA

 

[chicopee]

These rims were dynamically balanced at a garage and with a measuring device integral with the balancing machine, you could see a slight wobble probably as a result of driving over potholes and the like.

 

[Tmoose]

Volvo for one publishes tolerances for radial and lateral runout for steel and alloy wheels. I'm thinking they were on the order of 1 mm. If the runout was less than that I'm not sure I'd expect a vibration problem on the car. Tire runout can be a problem by itself.

Was the purpose of the balancing to correct a vibration problem?

 

[MikeHalloran]

Did you see the wobble in the wheels, or in the tires?

I got a set of JCPenney tires that really couldn't be balanced properly, because they were 1/2" out of round. The outsides were fuzzy when spun on the dynamic balancer.
Damn POS tires wore like iron, beat the crap out of the car.


Mike Halloran
Pembroke Pines, FL, USA

 

[GregLocock]

I'm inclined to think that old steel rims were probably made of material that can be beaten back into shape without cracking it. Obviously you'll use one of its nine lives up. You need to check whether it is local distortion of the rim, or whether the whole spider (the disc part) has been canted over.



Cheers

Greg Locock


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[chicopee]

Balancing was to correct a vibration of the front wheels and this balancing corrected the problem when I drove the vehicle. One rim wih the lesser wobble was hand rotated on the balancing machine in front of me and this wobble was imperceptible but there nonetheless. Two other wheels would also wobble (which I did not witness) but slighlty worse according to the mechanic. I have test driven the car afterward around 65 mph and there was no noticable vibration or side drift that the mechanic alluded to with wobbling wheels.
While 14" rims are available, none would fit the hub caps, so the question remains can these rims be restored to proper tolerance? The mechanic said it could not be done and I am the type of a guy that does not give up until there is certainty.

 

[patprimmer]

So what actual problem are you trying to solve?

Regards
Pat
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[GregLocock]

"there was no noticable vibration or side drift that the mechanic alluded to with wobbling wheels"

Wobbling wheels would not cause side drift.



Cheers

Greg Locock


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[Tmoose]

"early 70s...vintage.....14 inch.... hubcaps...."

sounds like steel wheels to me.

If neither I nor my pickiest passenger notice any vibration in the steering wheel, seats, or rear view mirror around 15 hertz when driving any speed between 40 and 80 mph then I think the wheel/tire runout and balancing are good enough.

The runout that is "visible" is undependable and hard to quantify. I think tire machines that (commendably) measure runout do so with roller pushing against the tire tread, so it is related to tire stiffness, not just the geometry of the unladen tire.

Not that Olde Volvos are luxuriously smooth highway runners, but one of the pocket "green books" has this:
Volvo 240 - max runout measured at the tire bead seat area (accessible only with tire removed)
steel wheels .032" radial 0.04" axial
alloy wheels .024" - 0.032"

i'd be more concerned with the tire tread runout, which is the sum of the wheel and tire runouts and how they are indexed relative to one another.

I think in the 70's Chrysler said 3/32 inch (about 0.09 inch) was the tread runout limit for police cars intended for high speed pursuit. Back then finding tires with assembled runout of 1/8 inch was pretty common. the few tires I've played with in recent years have impressed me with the much improved accuracy of manufacturing.

i think the 'side drift" that the mechanic referred to was a "waddling" motion/ sensation at low speed. An extreme but unmistakable example is the waddle that results when a radial tire's belt separates. An inspection of the tire generally reveals a HIGHLY visible "wow" in the tread runout.

https://groups.google.com/forum/?hl=en&fromgroups=#!topic/rec.autos.sport.tech/_4_d156LQZU

 

[patprimmer]

In all my years, the only time I ever experienced side drift in tyres was due to mismatched uneven wear on the front from poor toe or camber adjustment or poor choice when rotating tyres or uneven air pressure or mismatched tyres on the front axle.

Regards
Pat
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