Piecing Together a Power Steering System

[charliec]

I'm trying to reconstruct the power steering system on my '68 Dart, 340. I know that I'll need both high-pressure and return hoses and possibly brackets, but I don't know what else.

When I bought the car, the under-hood steering mechanisms were missing except for the steering gear. It had a power steering box, but no pump, no hoses, no brackets. It steered manually through a power steering box. It was pretty much meant to run in a straight line, ¼ mile at a time.

I'm trying to put it all back together as a functional power-steering street car. I bought a K-member from a '73 Duster some time ago, and it came with a power steering box on it. So, when it came to rebuilding a PS box, I chose to use the later model. They appear to be the same dimensionally, so that's the one I'm working to. Firm Feel did the rebuild on the steering box.

I bought a power steering pump from someone here on A Bodies Only. I had it rebuilt by Firm Feel. Their invoice notes "Thompson"; other than that, I don't know what manufacture it is, what year it is, or what it came off of. About all I can tell you is that the high-pressure outlet thread is 5/8 - 18 female. It has a 3/8" clamp nipple for a return line connection. Following leads that I can glean from the '68 Parts Catalog, the reservoir body is 4-5/8" diameter. There is no keyway in the pump shaft, and it has no threaded hole or hex holes in the shaft. It came with two bracket pieces, but I still don't know what it came off of and if the brackets will work.

Coming off of the PS gear, there is an adapter on the high-pressure inlet to go from the threaded female hole in the gear (maybe 3/8" ???) to a flare fitting for the hose (maybe 1/4" flare ???). I can measure that fitting tomorrow to clarify.

Pertinent photos are attached.

If anyone can make sense of all of this and help me identify the parts I have it would be a big step forward to connecting the dots on what other pieces I'll need.

 

[Kendog 170]

Here's a pic of the two pumps used that style. Looks like yours's a TRW Pump.

 

[AMC Diplomat]

There's a whole rebuild article about these. I know yours is already rebuilt, but it's more information than you're probably looking for: Chrysler Thompson Federal Steering Pump Rebuild - Poly318.com

As for the hose fittings to go from the 68 pump to the 73 box I don't know. Someone wiser than me will. In the absolute worse case scenario you can have a set of hoses made with the right fittings

 

[S'cuder]

In case you don't know, one thing that may come into play is your pitman arm from your 1968 is probably different than the one needed for the 1973 steering gear. The sector shaft to which it attaches is slightly larger than the one your 1968 gear. Also, the pitman arm stud that attaches to the center link is oriented differently in that it points down, not up. That's assuming both are the originals. All of this could require swapping the pitman arm, idler arm, and center link to match. There may be a large sector shaft pitman arm in the 1968 configuration. That would take further investigation or someone with more knowledge than me chiming in.

Also, does the engine have a pulley with a groove for a power steering belt? It could have been swapped out.

The T in TRW stands for Thompson. Thompson made auto parts for 50 years before RW came on board. It's possible the design of the pump predates the merger. Regardless, Thompson and TRW are interchangeable in this instance.

 

[charliec]

Thanks for all of that. Good catch. I have probably (unknowingly) worked around those issues. As I mentioned, I bought a 73 Duster K member. So happens that all of the steering apparatus was included...geer, Pittman arm, center link, etc. So, when I refurbished all that stuff, it was the 73 version.