Mercruiser power steering control valve issue

tg75

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1996 Mercruiser 4.3LXgen+ SN:0F826592

I have a power steering issue. In short the system steers hard at all times and conditions. Steering control valve and actuator is a newer style with no serviceable parts.

A bit of trouble shooting has brought me to this. The control valve is not moving enough with input from steering wheel via the steering cable. If I assist the control valve by pushing or pulling on the end of the valve where the steering cable attaches, all works fine. Without the extra input no power steering.

So a couple of questions.
1. Is this a control valve issue? Simply replace the control valve and actuator assembly?
2. Is this a steering cable issue that is causing the control valve to not move enough to allow PS fluid to actuate the piston, thus replace the steering cable assembly?
3. Or could it be a pump issue, not enough pressure?

Thoughts and guidance appreciated.

Thanks
Travis
 

alldodge

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Howdy

I would remove the cable the reinstall noting the slots are vertical (view d) and the nut is tightened down

Steering Ram.jpg
 

tg75

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Thanks for the suggestion AllDodge.

I have pulled the clevis pin (g) from the clevis (f) and ran the cable back and forth via the steering wheel. All was free and easy. Did also loosen the cable coupler nut (c) and reorient the slots vertically (they were at about a 60 degree angle) then retighten. Still same issue. However, I did not pull the cable through the cable guide tube and out of the valve assembly completely and reinstall. Can certainly give that a try.

Also found a bit of looseness under the dash where the steering wheel inputs to the steering cable, so tightened all of that to take out any play from that end.
 

alldodge

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Play under the helm only has an effect on how much play you have in the overall steering. The inner core of the steering cable just needs to be inserted into the cable guide tube until it stops on the inside, then the nut gets tightened down. So if the outer cable jacket does not have any play in it, then it should be good.

The ram control valve is not adjustable, look at what the inner cable is making contact with inside the ram. Other then that it should work, its pretty simple device but sounds to me that something inside the ram is not making contact with the cable
 

tg75

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This is what it look like just before I slide the cable up to the tube and tighten the nut. I am not sure what AllDodge means by, "inner core of the steering cable just needs to be inserted into the cable guide tube until it stops on the inside". There is nothing to slide into the tube other than the steering cable end to attach to the clevis. Am I missing something or is this correct as shown in the pic?

How much resistance should the shuttle tube (threaded part of the picture provide). It can be actuated when I assist it and I can move it when the steering cable is out but with some noticeable resistance. Shout it move freely or should it have resistance?

Also, when all is assembled and I crank the steering wheel quickly, I notice some chatter in the valve as it attempts to actuate the ram but only if I work the steering wheel very quickly.

Thanks.
 

alldodge

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Think I miss spoke but still looking and trying to remember when I replaced mine (old guy).

Looks like need to not use photobucket anymore, need to upload pics, use google or another. I never did like photobucket anyway
 
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