Power steering excess play.

Hi Folks, New to this forum. I need help tracking down excess play in helm. It is a rack and pinion on a 1988 Thompson 24' with Mercruiser 260hp. There is a pump in corner that sits on top of a plastic reservoir of oil and a piston actuator. The auto type power steering pump is on front of engine and fluid is cooled through a cooler then goes to the pistons. I just got the boat and don't know much history. I do know the marina mechanic recently installed a top end (used) on the Alpha drive. Don't know if he looked at the arm. My question is the procedure to check things through the process of elimination to find specific problem. I estimate the play from center helm is 4" left to 4"right of the wheel - too much to keep a straight course. I have some pics. but don't know how to post them. Any help is always appreciated. TU Jim

My question is the procedure to check things through the process of elimination to find specific problem.

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Ayuh,.... To do it right, it takes 3 people, 1 at the helm, 1 at the drive, 'n the 3rd to eyeball all the connections in-between,.....

Step #1 is the guy at the drive holds it tightly, while the helm is moved to each side, 'n the connections are inspected,.....
Step #2 is the opposite, the helm is held tightly, 'n the drive is shaken, while the connections are observed,....

Possible wear points include, the helm itself,.... the cable,.... the p/s unit on the transom,.... the pins connectin' the cable to the p/s unit, 'n the pin from the p/s unit to the tiller arm,....
Finally, the tiller arm to the drive,....

With the motor off, there's gonna be 'bout a 1/4" of slop in the p/s unit at the shuttle valve, but that goes away with the motor runnin',....

If this is about the boat wandering at idle speeds, the slop ain't the problem, but it's typical V-hull wander, which is cured with practice, 'n less operator input,....

Btw,..... The pump with the plastic tank in the corner, is the trim pump,..... nothing at all to do with the steerin',....

Bondo, thanks for the info. I kinda thought the procedure would entail several people. I got the boat late last year so have not had time to do much with it. One thing I did notice was a small oil container/pump mounted in center of transom with two small hoses going through transom that I thought might be the oil supply for trim tabs. I am going to have to take a lot more pics in the spring. It must sound like I am a dummy but I have been boating for over 60 years, just nothing like this one. I have had three cruisers, including my last, a 34' Inland Seas, a 28' Steelcraft and a 33' Owens. Just downsizing to something I can operate myself. I have a few pic. but don't know how to upload to this site. Thanks, Jim

Prime Time II said:

Bondo, thanks for the info. I kinda thought the procedure would entail several people. I got the boat late last year so have not had time to do much with it. One thing I did notice was a small oil container/pump mounted in center of transom with two small hoses going through transom that I thought might be the oil supply for trim tabs. I am going to have to take a lot more pics in the spring. It must sound like I am a dummy but I have been boating for over 60 years, just nothing like this one. I have had three cruisers, including my last, a 34' Inland Seas, a 28' Steelcraft and a 33' Owens. Just downsizing to something I can operate myself. I have a few pic. but don't know how to upload to this site. Thanks, Jim

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Ayuh,..... It sounds like ya got 3 hydraulic systems on board,....

The P/S system is the belt driven pump on the motor, to the actuator on the transom assembly, to the cooler, probably under the motor(which needs to be drained in freezin' temps), back to the pump on the motor,....

The 2nd, is the trim pump, with the plastic tank in the corner, raises, 'n lowers the outdrive,.....

The 3rd, sounds like Bennett trim tabs, which helps control hull trim on plane, that pump moves the tabs down, 'n they're spring returned to the up position,....

Those old rack and pinion helms have a lot of slop in them, annoyingly so. Best wait and check it out on the water and see if it's sloppy when you have it up on plane. Going slow and around the ramp you'll be tearing your hair out with all the play. Single stern drives are pretty uncontrollable at low speed and having slow helm with tons of slack makes it more challenging.
There are solutions, all of which are several hundreds of boat dollars. You probably will not be able to get a replacement cable for your rack and pinion helm, they just don't make those anymore. The best option is to convert to hydraulic steering but that's about 2500-3000 unless you can put one together from eBay parts.