1937-1957 Buick Oldsmobile Pontiac suspension upgrade
From Crankshaft Coalition Wiki
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==Overview== | ==Overview== | ||
A suspension and disc brake upgrade on a 1937-'57 Buick, Olds, or Pontiac (BOP) is complicated by many variables and side issues. In addition, there is little information on the topic, and few aftermarket parts are available. | A suspension and disc brake upgrade on a 1937-'57 Buick, Olds, or Pontiac (BOP) is complicated by many variables and side issues. In addition, there is little information on the topic, and few aftermarket parts are available. | ||
With minor variation between models and years, Buicks, Oldsmobiles, and Pontiacs share a common frame and front suspension. Chevrolet did not have this setup. | With minor variation between models and years, Buicks, Oldsmobiles, and Pontiacs share a common frame and front suspension. Chevrolet did not have this setup. | ||
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==Original suspension details== | ==Original suspension details== | ||
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Postwar, they were 2-1/4" by 12”, with 1-1/8” wheel cylinders. The most basic upgrade would be to the later, larger, components. Control arms and spindles are unchanged for 20 years, so this is a basic bolt on. Even the shop manuals refer to this upgrade. | Postwar, they were 2-1/4" by 12”, with 1-1/8” wheel cylinders. The most basic upgrade would be to the later, larger, components. Control arms and spindles are unchanged for 20 years, so this is a basic bolt on. Even the shop manuals refer to this upgrade. | ||
| − | The single reservoir master cylinder is located under the floor and bolted to the frame. A new split system | + | The single reservoir master cylinder is located under the floor and bolted to the frame. A new split system master cylinder and power [[booster]] will be an amazing transformation of your stopping ability. Several aftermarket master cylinders and 7” boosters (with universal pedal mounts) are available. With a V8 engine swap, a 7” booster seems to be the most you can squeeze under the hood. |
The Geo Metro hanging pedal and 7 inch booster is one option, but the MC (master cylinder) is small. Didn't chase down a match, but the center hole and bolt pattern appear to be typical GM. Be sure to get one designed for a booster application, and pay attention to the pushrod length. | The Geo Metro hanging pedal and 7 inch booster is one option, but the MC (master cylinder) is small. Didn't chase down a match, but the center hole and bolt pattern appear to be typical GM. Be sure to get one designed for a booster application, and pay attention to the pushrod length. | ||
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If you elect to do a power-only upgrade, and keep 4-wheel drums, be aware most master cylinders are designed for a disc/drum setup, and you will have to add 10 psi residual valves to the front lines. | If you elect to do a power-only upgrade, and keep 4-wheel drums, be aware most master cylinders are designed for a disc/drum setup, and you will have to add 10 psi residual valves to the front lines. | ||
| − | *The front drums and hubs come together, at about $130 each | + | *The front drums and hubs come together, at about $130 each |
| − | *Wheel cylinders are $32 each | + | *Wheel cylinders are $32 each |
| − | *Shoes are $25 plus cores | + | *Shoes are $25 plus cores |
| − | *Hardware is $15, flex hoses are $25 each | + | *Hardware is $15, flex hoses are $25 each |
| − | *The above mentioned wheel bearings are $200 | + | *The above mentioned wheel bearings are $200 |
| − | So, a complete brake job will run around $600 just for the | + | So, a complete brake job will run around $600 just for the two front wheels, without the master cylinder or booster. |
===Disc brake upgrade=== | ===Disc brake upgrade=== | ||
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*[http://www.scarebird.com/6928.html Scarebird Classic Brakes] makes a setup for many General Motors makes and models. They supply the brackets for the calipers and the correct spacers for the spindles/rotors, and a tech list of parts to finish the job, for $100-$150, depending on application. For example, for a '58 Pontiac, they supply the brackets and spacers. From any source, new or used, you need a pair of '77 Bonneville 12-inch hubs/rotors, a pair of '88-'91 GM truck calipers, and 2 choices of flex hoses, depending on whether you want them 12 or 15 inches long. | *[http://www.scarebird.com/6928.html Scarebird Classic Brakes] makes a setup for many General Motors makes and models. They supply the brackets for the calipers and the correct spacers for the spindles/rotors, and a tech list of parts to finish the job, for $100-$150, depending on application. For example, for a '58 Pontiac, they supply the brackets and spacers. From any source, new or used, you need a pair of '77 Bonneville 12-inch hubs/rotors, a pair of '88-'91 GM truck calipers, and 2 choices of flex hoses, depending on whether you want them 12 or 15 inches long. | ||
| − | * | + | *[http://classicperform.com Classic Performance Parts] sells a tapered bearing conversion kit. |
If you are using all new parts, you can have disc brakes cheaper than rebuilding the original drum setup. | If you are using all new parts, you can have disc brakes cheaper than rebuilding the original drum setup. | ||
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Also, we do not have a '58 Olds available to check/measure the lower control arms. What we DO know is '57 is king pin, and '59 is all-new. So '58 is it. We used the '58 Pontiac upper control arms simply because we got the whole front end. Several uppers will work, as it looks like '58 to '60 BOPs all had the same basic dimensions on their upper control arms. In fact, the '58 Buick uppers we used on one conversion had some built-in twist that allowed us to add more anti-dive than we could get with the Pontiac uppers. | Also, we do not have a '58 Olds available to check/measure the lower control arms. What we DO know is '57 is king pin, and '59 is all-new. So '58 is it. We used the '58 Pontiac upper control arms simply because we got the whole front end. Several uppers will work, as it looks like '58 to '60 BOPs all had the same basic dimensions on their upper control arms. In fact, the '58 Buick uppers we used on one conversion had some built-in twist that allowed us to add more anti-dive than we could get with the Pontiac uppers. | ||
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| + | Updated addition- 1958 Olds lower arms are not symmetrical, and like Buick will not work. | ||
As you can see in the photos, the '58 control arms are more substantial than the '41. However, all the dimensions are the same. | As you can see in the photos, the '58 control arms are more substantial than the '41. However, all the dimensions are the same. | ||
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| − | For spindles, the '63 Pontiac spindles advised in the article were used. Unfortunately, when it was set it on the ground, the front ride height was too high. This led to a search for dropped spindles. For BOP, dropped spindles couldn't be found | + | For spindles, the '63 Pontiac spindles advised in the article were used. |
| + | The '63 Pontiac spindle has a deep 90 degree bend at the bottom, to clear the wide corners on the lower control arm. (The '60s stock Chevy spindle has a 45 degree angle at that location, so Chevy Spindles won't work.) Unfortunately, when it was set it on the ground, the front ride height was too high. This led to a search for dropped spindles. | ||
| + | For BOP, dropped spindles couldn't be found but Chevy drop spindles are readily available. | ||
| + | Note the side by side comparisons in the picture. | ||
{| | {| | ||
|[[image:63_pontiac_65_chevy_spindle_2.jpg|thumb|center|400px|Pontiac (bottom) vs. Chevy spindle shape]] | |[[image:63_pontiac_65_chevy_spindle_2.jpg|thumb|center|400px|Pontiac (bottom) vs. Chevy spindle shape]] | ||
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| + | The spindle on the left, shown above is the '65-'70 Chevy drop spindle from Classic Performance Products. It's their own in-house design and is very close to the design of a Pontiac spindle. | ||
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| + | The ears had to be trimmed off the front side of the lower A-frame, but that was a minor modification. | ||
[[image:IMGP0005.JPG|thumb|left|400px|Trimmed lower control arm]] <br style="clear:both"/> | [[image:IMGP0005.JPG|thumb|left|400px|Trimmed lower control arm]] <br style="clear:both"/> | ||
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CPP's dropped spindle is available alone, or in a disc brake kit. Be sure you get the p/n CP30101 spindle. It has no steering arms built in. | CPP's dropped spindle is available alone, or in a disc brake kit. Be sure you get the p/n CP30101 spindle. It has no steering arms built in. | ||
| − | Stock spindles are front steer, and won’t work. With the CP30101, you can just add a pair of '65-'70 stock arms. Flipped over, they fit your rear steer perfectly-even the taper is the right direction. Unlike the '63 Pontiac arm in the article, the Chevy arms are pretty straight. | + | On the Pontiac spindles, the distance between the mounting holes of the steering arms is different from the Chevy's ones, so you have to use Chevy steering arms on the CPP spindles. |
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| + | Stock spindles are front steer, and won’t work. With the CP30101, you can just add a pair of '65-'70 Chevy stock arms. Flipped over, they fit your rear steer perfectly-even the taper is the right direction. Unlike the '63 Pontiac arm in the article, the Chevy arms are pretty straight. | ||
For this project, the tie rods only needed to be shortened less than an inch, rather than the 3 inches in the article. This was done by trimming a little off both the inner and outer tie rod threads and the sleeve. No cutting and welding. | For this project, the tie rods only needed to be shortened less than an inch, rather than the 3 inches in the article. This was done by trimming a little off both the inner and outer tie rod threads and the sleeve. No cutting and welding. | ||
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[[Category:Suspension]] | [[Category:Suspension]] | ||
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