Tech Section with Brian Alley

Power Steering Adapted From A 91 Chevy S-10

First, let me state, this is not the easiest conversion. I had a few very strict goals I wanted to accomplish when I one this conversion, and it follows along with some of my other mods to my rig.


1. Use as many common of the shelf parts as possible, from as few different vehicles as possible.

2. Make as little or no modification to the normal wear/replacement parts. This will make service on the trail or even in the shop easier. The parts should be able to be installed with common hand tools, no cutting, welding, or other heavy mods to the parts.

3. Be as cheap as possible to do.

Sounds easy enough. On with the install.

Since it was raining and wet when I decided to start the conversion, and my shop was full of customer vehicles waiting on parts, the first thing I done was make three slugs to weld into the frame rail for mounting point on the steering box. These were a simple job on the lathe, just some cold rolled round stock, turned to an OD of 1 inch, with a bore thru them of 7/16inch, and faced of 3.75inches long. These will weld to the frame rail, and allow me the factory steering box bolts.

Then it was on to make a power steering pulley. I decided to make a pulley  after studying some other systems, and looking at the stock GM system I was going to be installing. All the power steering parts came from a 91 Chevy S-10 pickup with a 4.3L V6 and automatic transmission. After deciding the parts will fit, one way or another, it was time to figure how to make them work on the Samurai. First thing I decided was the pulley was going to have to be the same diameter or smaller than the 1.3L crank pulley. the stock GM crank pulley was 8" diameter, and the P/S pulley was 6.5" diameter. Using the 6.5" pulley on the stock 1.3L crank pulley groove which is 4" diameter just will not spin the pump fast enough to make it work right.

I cheated just slightly in making the pulley. The stock GM pulleys are two pieces, the center hub comes right out in a press. Without a press you could heat the center to release the brazing and knock it out with a hammer, but it may distort the press fit to the pump shaft it needs.

After removing the center and cleaning it up a little in the lathe, I started on the pulley.  The pulley started life as a block of steel roughly 5"x6"x1"thick. I have no idea what type of steel it is, it came from the scrap box. It has been there for a good 6 months or so and has not rusted so that may be a clue.

Here is a series of photos showing the start to the pulley The Square block of steel, setup and centered in the four jaw chuck. A1/2" hole was drilled to allow the boring bar to be used to open up the hole or the original pulley center hub to be mounted

Opening up the center bore


The center bore is opened thru the entire thickness of the plate, then the front side is relieved oversized to do the final work after the center hub is installed. This relief will allow the pulley remover/installer tool access.



The blocked has been removed from the lathe, and is mounted in a small press type fixture I have. The center hub is a light press fit into the block, you will notice a shaft stuck in the hub. It is there to use for mounting the piece back in the chuck and is a press fit to the hub, just like the P/Spump shaft. 


After TIG the hub into the block it is returned to the lathe for some more work


After spinning to the piece to see how true it ran, and marking out the rough 4" diameter I took it to the chopsaw and clipped of the corners to save some time in turning. About 10 minutes of turning work and you can see by the third picture it is almost round.


Here is the pulley completed. Sorry I didn't get any of making the groove in the pulley. After some research in a few books, I found the correct angle called for on the pulley was 36degrees. split that in half, set the compound at 18 degrees and cut on side of the groove, then swing it to 18 degrees on the other side and cut again. Yeah, I know my TIG welding needs work. I haven't done it in a while, and it is kind of like welding while patting your head and rubbing your tummy at the same time:-)


08/11/10 15:20



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