"Groan" in Steering Wheel

[Defender]

2003 GMC 2500HD.....Has intermittent "groan" in steering wheel. Not related to intermediate steering shaft. Any ideas?

[More Power]

I suspect a small amount of play in the steering system contributes to a hydraulic oscillation under specific conditions. I've noticed the same thing to a small degree - only happened a couple of times in 10 years, hard to reproduce, don't consider it an issue.

Jim

[carco]

If my LLY has been driven a long distance and is hot; when @ stops and steering under a load or when rolling very slowly and turning quickly loading the steering pump mine will moan/groan/ and have reduced power. I believe the PS oil is overheated, maybe aerated, causing a reduced pressure and the associated problems. A few minutes of cool down time cures the problem. A cooler would prob go a long way to prolonging the ps sys life.

[DmaxMaverick]

If you are having heat issues with your power steering fluid, don't use power steering fluid. Flush/fill it with synthetic Dexron-III ATF (Mobil-1, Amsoil, etc.). Very easy to do. Adding a cooler is always a good idea, but the improvement will be MUCH less than you would expect. With synthetic fluid, a cooler is not necessary, as excessive temps for traditional PS fluid is nowhere near the operating range temp for synthetic.

[carco]

DmaxMaverick, yes except those systems on PS oil vs automatic oil we have been told by ACDelco and Motorcraft not to switch the systems oil due to possible seal compatibility. May or may not be an issue in the truck but is most likely an issue in a rack and pinion system, which our heavier trucks are not.

[ToddMeister]

I've also noticed the same thing on my 05 LLY after a long drive in hot weather.

This past summer I flushed out the PS system and filled with synthetic PS fluid, also added a PS cooler to the return circuit. No more moaning/groaning since.



If my LLY has been driven a long distance and is hot; when @ stops and steering under a load or when rolling very slowly and turning quickly loading the steering pump mine will moan/groan/ and have reduced power. I believe the PS oil is overheated, maybe aerated, causing a reduced pressure and the associated problems. A few minutes of cool down time cures the problem. A cooler would prob go a long way to prolonging the ps sys life.