[squablow]

Hello all, I just recently joined the forum to be able to view some wiring diagrams that were very helpful. So I thought I'd contribute a helpful discovery I made recently.

I've had this '72 for nearly 25 years and I've recently been trying to work out some of the bugs it's always had, one of which was it's always had a bit of a side to side wiggle at speed. I replaced the front tires and had a very hard time getting them balanced, the new tires acted differently than the old ones but it still had the wiggle.

Reading more on these forums and some others I learned about the lug-centric design of the Pontiac Rally II wheel and how a regular spin balancer with a centering cone (like mine) doesn't have any good way to locate the wheel on the balancer. The cone doesn't have a perfectly centered round hole to fit into. It'll fit into the back side, but when I tried to balance it that way, the balancer would ask for different weight amounts every time and never zero out.

[squablow]

Apparently, the solution to this is to have a "pin plate" for the wheel balancer that uses the lug nut holes to center it instead of a cone. If you can find a tire shop that has one of those who will balance the wheels, you'll have no problems.

But for guys like me, a small shop that already has a balancer and wants to do it myself, or if you can't find a local tire shop near you that has the pin plate, this is an issue.

I looked into buying a pin plate for my Hofmann tire balancer, but the cost was around $2100, and I can't spend that kind of money, especially on a machine I bought at an auction for $140.

So for the princely sum of $32 shipped, I bought a pair of these billet aluminum wheel adapters/spacers, with the 4 3/4 pattern. Bolting them to the back of the wheel gives me a nice machined accurate center hole that is located by the lugs on the wheels and I was able to get all of my tires balanced better than they have ever been.

I will say that even with the accurate hole for the cone to go in, the "cup" side of the balancer isn't pushing directly on the face of the lug holes like it would on a plain steel wheel, it's going through the center cap hole and pushing against the face of the center cap area or kinda the face of the spokes, which also isn't real accurate, so I had to play with it a few times to get the wheel on the balancer nice and straight. But once I had it on there, they balanced out totally normally, no more walking around on the cone or crazy weight numbers getting spit out.

[squablow]

I wanted to share this because I learned so much recently from old forum posts that I found searching the internet and if even one person sees this and it helps, it was worth mentioning. I'm sure this would also work well for Polycast wheels and Oldsmobile SSIII wheels, and probably the Buick Road wheels too

Years ago I actually sold a very nice used set of the chrome Buick rally wheels and shipped them to a guy who said all 4 were badly bent and junk and demanded I give him a refund. He said his tire shop spun balanced them and they were all horribly bent. I sent the guy a refund but I always felt shocked that those wheels were bent, they were so clean. Now I'd bet any money that they were perfect and the tire shop he was working with was trying to use a cone on them. Live and learn, I guess.

[foxgapLeMans]

This will help me, I have been searching around my area for a few months for a shop with a lug centric adapter, no luck so far. I used a bubble balancer but I still think they are a bit off. The wheels are 15" Honeycombs.

Thanks, Mark

[squablow]

Originally Posted by foxgapLeMans

This will help me, I have been searching around my area for a few months for a shop with a lug centric adapter, no luck so far. I used a bubble balancer but I still think they are a bit off. The wheels are 15" Honeycombs.

Thanks, Mark

Sweet! Definitely worth a shot, if it works well or if there are any special issues you run into with the honeycombs, be sure to post up info, it'll be useful to others in the future.

My car's telltale wiggle seems to be totally gone now, I had lived with it way too long.

[bdk1976]

I've had similar issues when balancing - looks like this could be my solution as well. Where did you buy these - can you post a link to the ones you are using?

[squablow]

Originally Posted by bdk1976

I've had similar issues when balancing - looks like this could be my solution as well. Where did you buy these - can you post a link to the ones you are using?

I bought mine on ebay, hopefully this link will work.

https://www.ebay.com/itm/312581458229

There are lots of others, but I chose these because they were a bit thinner (I don't want the wheel to be way out on the end of the balancer, that was already an issue on my particular balancer, the shaft isn't super long) and also because the center bore hole of these is smaller than some of the others I've seen, which fit on my cone better. I only have 2 cones for my machine, a decent tire shop would probably have more sizes and then the center bore hole size wouldn't matter as much. Couldn't argue with the price, either.

[Tarl]

Squablow, not related to the topic but I love your 72, had the exact same convertible, same color, minus the hood tach and spoiler..... until some 18 year old t-boned it.

[squablow]

Originally Posted by Tarl

Squablow, not related to the topic but I love your 72, had the exact same convertible, same color, minus the hood tach and spoiler..... until some 18 year old t-boned it.

Thanks! I bought this one in 2001, a week after my 21st birthday. I added the tach and spoiler (as if that wasn't obvious) and I also had Judge stripes on it up until recently. I decided to delete the stripes and let it be what it is instead of a clone. I like the tach and spoiler yet but next year I might paint them body color, would be more correct that way, and I've got a set of sport mirrors I'd like to add as well.

It is an original rubber nose car but it's not a Sport, it has a bench seat, which is kinda interesting. It's also was originally orange and black but it was a 2bbl 350, the 455 was added.

Shame about your car getting T boned, unfortunately a lot of legendary cars met their end that way.

[65madgoat]

Originally Posted by squablow

Sweet! Definitely worth a shot, if it works well or if there are any special issues you run into with the honeycombs, be sure to post up info, it'll be useful to others in the future.

My car's telltale wiggle seems to be totally gone now, I had lived with it way too long.

I think the work around to getting honeycombs balanced is putting the rim on the balance machine backwards. That way the little cone goes in to the steel backside hole and not into the often distorted polycast front hole which is what throws off a balancing job.

[squablow]

Originally Posted by 65madgoat

I think the work around to getting honeycombs balanced is putting the rim on the balance machine backwards. That way the little cone goes in to the steel backside hole and not into the often distorted polycast front hole which is what throws off a balancing job.

Could be, I never had to balance a set of Polycast wheels. I had some years ago but sold them, if I ever get anymore, I'm definitely going to experiment with that.

On my tire balancer, the inside of the wheel is always where the cone goes, the inside of the wheel faces the balancer and the outside faces away, the outside face is the one that gets the "cup". Mines a Hofmann, others very likely could be different.

I did try to mount a Rally II to my machine backwards, using the center cap hole as the locating hole on the cone, but it doesn't work. The center cap hole on the Rally II isn't very precise, and the wheel would just move around and all the weight of the wheel was off to one side.

If anyone else has had success balancing a Polycast wheel with the wheel mounted backwards on the balancer, please comment, it would be good to know from multiple people if that works.

[squablow]

I was curious and I looked at some pics online of some Polycast honeycomb wheels, and I do think 65madgoat is right, it does look like the backside would hold a balancing cone just fine. Maybe you'd need one on the back and a smaller cone in front, going through the center cap hole to tighten against instead of the plastic rimmed "cup" part of the balancer, because the cup would have to be in contact with the rubber part of the wheel. I'm not sure, but that does look like a different scenario than the Rally II wheel. I wish I had one of those around to experiment with.

[65madgoat]

Yes I had a shop balance the honeycombs that way - backwards. As I was initially looking to buy those lug centric adapters since no shop here has them.

But low and behold, just putting honeycombs on backwards was ideal. Spot on balancing.

[Skip Fix]

Finding a lugcentric balancer here in Houston is hard. My Weld ProStars are a weird almost 2 piece that squeeze a center moveable spacer in the center when you tighten lug nuts. I'm going to give your adapter method a try!

[squablow]

Originally Posted by Skip Fix

Finding a lugcentric balancer here in Houston is hard. My Weld ProStars are a weird almost 2 piece that squeeze a center moveable spacer in the center when you tighten lug nuts. I'm going to give your adapter method a try!

If you try it, I'd like to hear how that works out, too. I'd kinda like to see what that looks like, but from what I'm picturing, the wheel adapter should hold everything in place to put the wheel on the balancer.

[65madgoat]

You can though find lug centric balancing adapters from China for $100 on amazon.... $450++ or so for truly shop grade ones.

[mrennie]

I tried getting my wheels balanced at the local garage using their lug centric adaptor but it was not working. Their adaptor used spring pressure to center in the lug holes and on several of my GM wheels, the taper of the lug nuts did not actually center in the stamped holes, kind of like they were stamped off center.

I ended up making my own adaptor with a front rotor by cutting off the disc area, and replacing the bearing races with bushings that were bored to 40mm to match the balance machine. This allowed me to bolt the wheel to the "adaptor" and the wheels seated where they typically would when the lug nuts were snugged up. This worked well but required a spacer to be made to allow the balance machine hand crank/nut to clear the tire/wheel .

Several of the GM wheels had some runout, so getting a perfect balance was not easy and required A lot of weight. IMO, factory Rally 2s (at least the late 70s ones I am using) look awesome but are not a precision made item...

[Shiny]

Thanks for this post!

I have some 14" rallys I'm going to have checked out at a tire store before I commit to tires.

This thread is great, establishes some realistic expectations!

[694.1]

Hey John, welcome to the forums!

[Skip Fix]

I thought about the cut down rotor also. I know guys do that to use as a hub for some of the brake kits.