1956 Buick Century CPP500 Power Steering box Conversion

[VickyBlue]

Steering box came in today. CPP50000-2 purchased direct from CPP. 

 

This is a new CPP 500 Series power steering gearbox. 

Our Steering box is a 14:1 ratio unit is a direct replacement for factory manual steering cars and is a direct replacement for the 605 power steering boxes. 

The 500 Series box provides:

• 100% Brand New Parts (Nothing Rebuilt)
• No Fabrication NEEDED!!(Bolts Direct to Frame Rail)
• 3 1/2" Lock to Lock 
• 5/8" Pressure port and 11/16" return port
• Provides More Header Clearance Than a 605 GearBox
• Superior Directional Control
• Better road feedback  
• Recirculating Ball Gears provide Low Friction and Increased Steering Response (CPP Engineered)
• Open Centered, Rotary Type Valve  (Smooth Operation Throughout The Steering Range) 

The 500 Series gearbox  will fit 1955, 1956, 1957 BelAir, Nomad, Wagon, Delray, 210, and 150 model Chevrolet Full-size Passenger Cars. This new P/S conversion gearbox is a modern alternative to the popular but outdated 605 box.  This is the very best gear-box available to convert your Tri-5 to Power Steering!

 

(Part Number #CP50000-2)

 

First thing I noticed, the 56 power steering pitman arm does not fit. Arm is too big for the CPP box. CPP box also has 3 mounting holes vs 4 the Saginaw box has. The CPP has smaller diameter holes than the 56 does. The input shaft on the CPP is smaller diameter than the 56, but it is splined. Both output shafts are tapered, the CPP box comes with it's own output shaft nut and safety washer, as the one from the 56 does not fit.

Willie has a pitman arm from a non power steering 55 Buick that is mailing to me. After going through some measurements over the phone, I think the non power steering pitman arm will fit the CPP box. 

The following measurements were taken in an effort to compare the two. Both output shaft measurements were taken at the same point, the guiding shaft pins, there are 4 of them. One measurement at the bottom (narrow end) and one at the top, (wide end). Shaft diameter was also measured. Mounting hole diameter, bottom mounting hole distance and top to bottom mounting hole distance. I will update with the manual steering pitman arm diameter once I get from Willie. 

 

56 pitman arm narrow end

 

56 output shaft narrow end (bottom)

 

56 output shaft wide end (top)

 

56 Arm wide end (pitman arm ball stud facing upwards)

 

56 box mounting hole diameter

 

56 input shaft diameter

 

CPP wide end output shaft diameter

 

CPP input shaft diameter

 

CPP top to bottom mounting hole distance

 

CPP mounting hole diameter

 

CPP bottom hole side to side distance

 

CPP output shaft diameter (wide end)

 

56 mounting hole distance top to bottom (equal on both sides)

 

56 output shaft narrow end

 

CPP output shaft narrow end

 

56 side to side bottom mounting hole distance

Edited December 24, 2016 by VickyBlue (see edit history)

[Beemon]

So this box won't fit, either? The bolt holes don't match up on both units by your measurements. Are you going to be doing some custom drill work?

[VickyBlue]

It looks like +1/4" on both bottom holes, but this is a guess. Once the new rag joint is here and attached to the column, I will have a better idea. The top one will have to be either re-drilled, or make a custom bracket. I will have a better idea once the joint is here and the box bolted on to the frame. 

[NTX5467]

I realize "the market" is with Tri-5 Chevrolets, but what about the '58-64+ Chevrolets and, all things considered, 55+ Buicks, Oldsmobiles, Cadillacs, and Pontiacs?  I suspect those other carlines are having similar issues with their cars?  Perhaps they need "donor vehicles" to prototype from?

 

I suspect the "manual steering replacement" is due to the fact that so many Tri-5 Chevrolets were non-power steering vehicles?  Considering that earlier power steering was "a column" integrated unit?  Be that as it may.

 

Something else I might be curious about is ultimate long-term durability with heavier cars and wider tires?  Especially the wider tires of modern vehicles and the additional torque they would require to turn when stopped?  But I guess that if they'll work reliably with a heavy "truck motor" 454 Chevy and wider radials in street rods, they'd be pretty good with a heavier Buick and lighter (than the Chevy 454) engine?

 

Please keep us posted on your progress!!!

 

Happy Holidays!

NTX5467

[EmTee]

Tri-5 Chevys with power steering used manual boxes with a hydraulic ram and control valve mounted on the center link.  My '56 has the PS pump mounted 'piggyback' on the rear of the generator, which has a longer splined armature shaft to engage the pump.

[VickyBlue]

Two other issues were found today: There is a .25" difference in the thickness of the ear tabs, the bolts go through, the CPP is thinner. The CPP pressure line is also different size, 7/16 tube and 11/16 -18 inverted flare.The original pressure line is 7/16-24. The return line is 5/8-18 inverted flare, which matches the original one. Russell adapter #648050 -6AN 11/16-18 inv flare should work. Will try NAPA tomorrow with the box, see if they can make me a line, or if they have a union 7/16-24 to 11/16-18. 

[NTX5467]

3 hours ago, EmTee said:

Tri-5 Chevys with power steering used manual boxes with a hydraulic ram and control valve mounted on the center link.  My '56 has the PS pump mounted 'piggyback' on the rear of the generator, which has a longer splined armature shaft to engage the pump.

 

Perhaps it was the '54 and prior with the "integral column" power steering gear?  The "generator/pump" lasted into the earlier 1960s, as long as the generator was used.  The 'linkage assist" system was used on Corvettes until the 1982 model year and also was on pickups into the middle 1960s.  And. of course, Ford loved that "linkage" system too.  Never did understand how those dangling hoses on the Fords managed to NOT get snagged on something!

 

NTX5467