Rally II wheels and disk brakes - Pontiac GTO Forum
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post #1 of 6 (permalink) Old 06-21-2014, 03:22 PM Thread Starter
 
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Rally II wheels and disk brakes

I put a disk brake kit on my 69 and now my 14" Rally II wheels bottom out against the calipers.

I posted a while ago about this and got some good warnings against shimming the wheel studs. I talked to the manufacturer and they said find rally wheels made for disk brakes. I think that was just to get me off the phone before I complained.

I tried grinding the inside of the wheel and the caliper but it needs more grinding than would be safe on both sides.

I really don't want to buy new tires for 15" wheels but I'm wondering if anyone knows whether there is a different variety of 14" Rally IIs that fit over disk brakes? I've been looking at Ames and OPG catalogs but their parts don't specifically mention disk brakes so I was wondering if maybe the ones they sell now are modified and it's just something everyone knows, everyone except me.

I don't find anything in any searches so I'm hoping someone else has been down this road.

Last edited by funbooker; 06-21-2014 at 05:05 PM.
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post #2 of 6 (permalink) Old 06-21-2014, 10:57 PM
 
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I think your problem is your choice of disc brake kit? 14" Rally's work on factory set-ups, but from what I have read they have to be later (post 1970) where the center section has been welded (I think further inward) in a different position to compensate for the disc caliper.

Now if it is your kit being the problem, then you will have to go to 15" rims as many kits do state this.

You don't want to shim the rim out, and I would not be grinding on a rim to clearance it.
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post #3 of 6 (permalink) Old 06-22-2014, 08:26 AM
 
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I agree. You have created several problems by grinding your rims and should replace them at this point. You will have severe problems getting the front tires in balance and have weakened the structure of the rim. Also, the heat created by grinding has changed the hardness of the steel.

At this point, I would suggest replacing them. Are you married to having the Ralley II rims on your ride? You may be able to find an aftermarket style that will work.
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post #4 of 6 (permalink) Old 06-23-2014, 03:03 PM
 
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Disk brakes were first offered as an option in '67, which incidentally, was the first year of the Ralley II wheels. The 14 inch Ralley II's were designed with disk brakes, as I understand it and should fit factory disk brakes. If you're running an aftermarket disk brake, then that is likely where your problem lies.

When the only tool in your toolbox is a hammer, you tend to see every problem as a nail.
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post #5 of 6 (permalink) Old 06-24-2014, 07:26 PM
 
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There were different 14" X 6" wheels for the early disc brake cars.
I have never compared them to verify if the differences are in the center section only, or if the outer ring is also different.

I have found this chart to be helpful:
Pontiac Wheel Applications

If you used all original, GM disc brake components (calipers, spindles, mounting brackets, lines) for your conversion, you should be able to use the correct 14 X 6 wheel. According to the application chart, the two-letter codes that will fit the OEM disc brakes on a 69 Tempest/Lemans/GTO are: HL JA JK JT KT KU
This is the code stamped on the outer section of the wheel, next to the valve stem hole.

HOWEVER, most disc brake conversion kits are not designed to work with 14" wheels and require at least 15" diameter wheels.

1968 Pontiac GTO
1983 Pontiac Bonneville (G) wagon
2008 Pontiac G8 base

Last edited by jmt455; 06-24-2014 at 07:30 PM. Reason: added explanation
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post #6 of 6 (permalink) Old 06-26-2014, 10:36 PM
 
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Pontiac made a bunch of different 14 x 6 Rally II wheels, and it can get very confusing.
If your kit is aftermarket, it just might be that no 14" will fit. However, if your kit uses alot of GM parts, there just might be a wheel that will fit.

In 1967, the first 14 x 6 Rally II wheels were "JA" and "JC" code. JA was meant for the disc brakes of that year, although the JC will fit those disc brakes too.
There are a couple other codes in '68 and '69 and '70 that will fit the discs, such as the JL code Rally II wheel I think.

The two problems with fitting a wheel around calipers is the radial height of the caliper, as well as the thickness (how far it sticks out toward the outside of the car).

Pontiac fiddled with two elements of the wheel "assemblies" to fit various applications: The wheel hoop (rim) and the wheel center (the spoke section)

The JA wheel mentioned above has a wheel "hoop" that accommodates the radial height of the 4 piston caliper, and the wheel center lug pockets are deep enough to keep the wheel center away from the wide caliper body. The JA wheel was used on the new-for-69 Pontiac A body single piston caliper disc brakes.

And, oddly enough, the "JC" wheel I mentioned was intended for drum brake cars, but I have personally tested them on disc brake (stock) rigs, and they fit.

After 1970, Pontiac changed the Rally II wheel center lug pocket shape to be less deep...so they won't fit wide (4 piston) caliper cars...they will only fit single piston set ups used in the 70's on up.

So, for your situation, there is still a risk even the JA, JC, or JL 14 x 6 wheel won't fit because you have aftermarket stuff. It still might be worth a try though....perhaps you know someone local who can let you trial fit one of those wheels?
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  Pontiac GTO Forum > The 1964-1974 Pontiac Tempest, Lemans & GTO > 1964-1974 Tempest, Lemans & GTO Wheels & Tires

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