I had the steering rack replaced with a refurbished part. It helped a lot. However there is till some looseness in the wheel before the steering kicks in. Maybe about 5 degrees of rotation. Is that just in the steering rack or is there anything I can tighten up to eliminate that? Also, I noticed with the new rack, if I start to steer from a cold start without giving it any gas, the truck likes to shudder a lot, however, I have a theory about this that I want to run by you. Follow my train of thought and let me know what you think.:

- I believe we have deduced that the cause of the oil pressure gauge jumping around is that the oil pressure is just on the verge of turning the gauge on and off, so it is jumping around as it turns on and off. I think this is caused by the oil pump not delivering enough oil pressure to stay above the 6 PSI and dipping into the 5.9 area. When you give the engine gas, that delivers more power to the oil pump, which increases the pressure, and the gauge stops jumping. It only jumps at low idle, since the engine is not proving enough power to the oil pump

- So deducing from that, over the last 21 years, the engine has lost some horses, and is delivering less power to the oil pump at idle.

- The power steering pump is also connected to the engine.

- At low idle, when you turn the wheel, the power steering pump is taking power from the engine, the engine isn't as powerful as it used to be, so it shudders. As soon as you give it gas, the shuddering vanishes, because the engine is now making more power and the excess drag from the power steering pump doesn't bother it.

Does that sound reasonable?

 

Look at the rag joint in the engine bay that connects the two steering shafts together, its there to isolate steering wheel from road vibrations/frame but can get sloppy

You "herd" Ford trucks, you never "drive" them, its quite relaxing compared to other vehicles

Yes, Ford steering pumps draw a few horse power when in use, i.e. turning the wheel, the 4cyl Rangers used to have a pressure sensor on the pump to raise the RPMs above idle when turning the wheel so they wouldn't stall, lol
People have tried non-Ford pumps for quieter operation as the Ford pumps can also be quite noisy


Oil pump spins at engine RPMs, and rule of thumb is 10psi oil pressure for each 1,000 engine rpms
So if engine is idling at 700 then there should be 7psi oil pressure

Oil pressure is BACK PRESSURE, its the oil the engine CAN NOT USE at that moment
The bearings and valve train can only pass a limited amount of oil thru its gaps, the oil that it can not use backs up in the main oil passage and oil filter and that's the "Oil Pressure" you see
Anything above 4psi at idle is OK, below that and you will HEAR valve train noise, 4psi is needed to overcome gravity to pump oil up to higher parts of the engine

Yes, Fords switch is set at 6psi more or less so can flicker at low idle
A "thicker oil" passes thru the gaps slower so can increase back pressure a bit, to keep it closer to the 7psi
i.e. using a 10w40 instead of 10w30

The Oil pump itself just pumps a volume of oil to the filter at 0psi, as long as the volume it pumps is greater than the volume the engine can use there will be back pressure built up
As engine RPMs go up the volume it pumps goes up but engine doesn't need that much more oil, so the back pressure goes up, i.e. Rule of Thumb 10psi pressure per 1,000rpm, so at 4,000rpm you should see about 40psi back pressure

 

Any pics/vids?

Yeah I am learning that these trucks have quite a bit of personality :)

Which leans into my theory that the shaking at idle is the engine struggling to power the steering pump without giving it any gas. I'm not particularly worried about it or care all that much, just curious if my idea was correct.

I don't care at all about the flickering gauge, I was just using that example to see if my "because the engine loses some power over the decades, the pumps attached to it (oil pump and steering pump) can act a little wonky" theory made sense
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Rag joint: https://www.therangerstation.com/tec...ng_coupler.PNG

 

What would I look to tighten on that?

 

Is there also an adjustment screw? Some Youtube videos make mention of an adjustment screw you can turn to remove slop in the steering

 

No screw adjustment on rack and pinion steering, older style steering gear boxes with Pitman arm had that adjustment


Look if there is slop in ragjoint while some turns the wheel back and forth a bit, you replace these, there is no adjustment
Easy to see, steering wheel shaft turns but shaft to wheels doesn't