I'm getting an intermittent groan from the steering. The noise ONLY happens at low speeds (ie: parking lots) and 99% of the time happens with left hand turns of more than 1/2 way to lock. It NEVER happens above parking lot speeds and seems to get worse when the system is warmed up. The truck still steers when the noise happens though it does seem to get a bit "harder" (though not significant...could be mental).


I THINK it is a bad rack.

I don't see how it could be the pump since the issue is position sensitive (pump just PUMPS and has no clue where the rack is in its travel) and happens almost always on left turns (almost never on right).

Fresh fluid, tight belts (just installed a manual tensioner last weekend with no improvements), everything is greased....I have checked everything I can think of.....

The pump is about 2 years old now (its a KRC cast iron pump http://www.krcpower.com/catalog_i651...l?catId=352909) and seems to provide PLENTY of fluid capacity. I went to this pump after the f-body pump died (I had done an f-body accessories swap).

This issue started in October time frame. Oddly enough it started the day after I swapped out my old intermediate steering shaft (had the infamous "clunking steering shaft"), though I can't for the life of me see how changing the intermediate shaft would CAUSE this.

I had the rack replaced in January (re-man rack I believe.....shop owner owed me some money so he did the swap/parts for free) but that didn't solve the issue.

Ideas?

 

Since the rack has been replaced, I doubt that's the problem, and I don't see how the pump could be the problem for the reasons you mentioned. This almost reminds me of a problem I saw on some Pontiacs in the early 90's (can't remember if it was Grand Prix or Grand Am...), anyway, there would be an inermittent groan/vibration from the steering when turning the wheel at slow speeds. Turns out it was an issue with one of the high pressure hoses to the rack, that would vibrate, and there was a re-designed high pressure hose to solve the problem. Maybe you're having a similar issue with one of your hoses, or one of the hoses are rubbing against something...quite possible since the accessories have been replaced and re-positioned...

 

well here is what I have discovered....

Looking at the rack (as someone works the steering wheel to make the noise occur), first off I see the rack MOVING. It seems the rubber bushings in the rack mounts (to the k-member) are flexing enough that the rack moves back and forth a good 1/2" or so. Once the bushings have pre-loaded, there is no more movement of the rack. Possible issue?

The lines are not touching anything and have been routed the same way for near 4 years now (same lines). Unless the lines could somehow go "bad", I'm not sure how it could be them.

The noise still seems to be coming from the rack. From the "top side", the noise seems "low" on the vehicle (not from the area of the pump). From the "bottom side", the noise is harder to pinpoint since it seems to echo in the body (though I still seem to eye it towards the rack area).

What would cause the rack to make noise? Why only at low speed/parked?

Something I noticed is that if I turn the wheel very slowly, the noise does NOT occur. Quicker movements cause the problem.

 

The rack will move somewhat as the bushings are rubber and have some give, but 1/2" seems excessive. This may create an issue...as for other causes of rack and pinion noise, I'd assume that if the internal rotary valve was worn it could create a noise and resistance in one direction or another.

 

Kind of far fetched, but I guess that it's possible that if the rack housing is internally worn, the rack could be dragging against one of the seals too...