300TD steering tension varies/tightens randomly after rebuild
 

After repairing my steering box on the wagon, the steering is nice and tight/stable, but depending on my speed or whether I just start the car, or are moving from a stopsign, etc it seems the tension radically changes, almost like the power steering gives out (about 75% off, still moves ok, but feels much tighter).

I'm wondering if since the steering pump uses a belt attached to the crankshaft pulley, if this is being all affected (ie loosening tension randomly) because the crankshaft seal is giving out (there is a major oil leak from the crankshaft front)?

When I replaced the steering box, I just left the steering pump as is. I pre-filled the box with fluid, bolted it on, and then ran the steering wheel back and forth probably 50 times. I'm fairly sure I purged all air, but wasn't sure if I needed to turn the steering wheel with either of the pump tubes off the box or the pump (ie return line loose sticking into the pump top so air gets out better).

But I drove it for maybe a week, and was fine, didn't notice a thing wrong with the tension, until just now as I'm noticing this major oil leak from the crankshaft seal.

I changed my alternator maybe 6 months ago and tightened it back up (never having the steering lock/tighten up until just now), new fluid (no leaking), etc. Will check tension on belt, but seems a bit odd since it comes and goes, like either the belt is at the end of it's life or something else is moving around.

If there is enough oil on the PS belt to cause it to slip it should be pretty evident.

But what you describe sounds consistent with a slipping PS belt.

It seems to be on pretty tight.... But I seem to notice that the power steering loosens up (to normal) when I'm turning as I accelerate. At idle (or near idle) it's really stiff. Almost like RPM's influence power steering pump function.

Maybe the belt is just so old that it's dried out and not gripping on so well. Definitely nothing I changed - I will try swapping with a spare.

Man, I love having a parts car, gives me so much opportunity to swap/tinker without buying a bunch of stuff that might not even be the problem.

Didn't think that motor oil (from leaking crankshaft seal) might be getting on belt. Will check that out.