My shop manual for my '73 says to use Automatic Transmission Fluid Type A or fluid designated as Dexron for the power steering pump. Since I can't find that stuff anymore, can I use the Dexron III stuff?

 

i put the ATF i use for my transmission also in my power steeering.

if i remember right somwehere from the C4 and up special steering oil is required

art-corvette

 

Originally in the 1950’s, automatic transmission fluid (ATF) was specified for both General Motors automatic transmissions and for power steering systems. But as vehicles got heavier, engines bigger, and temperatures hotter, the requirements for the two different systems changed. The GM Research Labs had a Lubricants Section that began testing and modifying the ATF formulation to improve the performance of the GM Hydramatic, Dynaflow, and Powerglide transmissions. They did this without much regard to the fact that the power steering system was using the ATF fluid as well.

So around the same time, Saginaw Steering Gear Division and Texaco tested and developed a fluid with lubricating and antifoaming properties specific for power steering. The fluid characteristics were formulated with particular emphasis on performance with respect to the ring, rotor, vanes, and the driveshaft bushing in the big Saginaw “P” model power steering pump. By the way, the “P” model was the only power steering pump used in all C2 and C3 Corvettes.

That is why some of the early power steering reservoir caps and owners manuals had ATF specified as the proper fluid to use. All the later pump caps and the owners manuals have said to use "Approved Fluid". The GM power steering fluid is approved for use in any vehicle with a Saginaw power steering pump.

I have no idea who formulated the PS fluid that is sold at K-mart, Pep Boys, NAPA, etc. This isn’t to say that it is bad. However, the amber colored GM fluid is the only fluid that has been certified and tested in GM durability test vehicles for millions of miles. It also is the only fluid that have been durability tested in the Saginaw Steering Gear engineering labs for hundreds of thousands of hours.

The GM part number for a quart of power steering fluid is 89020661. The previous GM part number for power steering fluid was 1050017. Any GM dealer can obtain the fluid.

 

Good grief Jim! I was going to wonder out loud how you managed to compile such a history of power steering fluid until I read through your public profile to see that steering was your career! Thank you very much for the insight!

 

on the info