Need help with a diagnosis, or at least help with what to look for....

Relevant Info : 2002 DII, 136K, TF steering damper, RP power steering fluid (changed about 6 months ago), took the truck off road this weekend and pushed it pretty hard, but the steering was fine on the way home from the trail. Tires were also rotated on Friday for the first time since new.

Diagnosis : Heavy steering/resistance, sort of an "easy-hard-easy-hard," "herky-jerky" motion, basically its more difficult than usual to turn the steering wheel and it is NOT a smooth motion. No whines, no clicks, no knocks, no new noises to report. Tracks fine down the highway.

It was pouring down rain and pitch black when I left for work this morning, so I didn't have a chance to check it out just yet.

What should I look for when I have a chance to check it out later today?

Thanks in advance.

 

fluid.

 

You think? Even with no whine?

 

it would be the first thing i check. lol... i would check the fluid amount, then the fluid smell, color.. i wouldnt taste it but i would do everything else... if all that checks out then it's time to get underneath. i would check the nut on the top of the steering box, it allows you to make adjustments. maybe it's loose and wreaking havoc. i would check to make sure all the tie rods are in good shape on the end of the track rod and tie rod bars and that you didnt bend anything. i would check the steering arm for damage. ... but fluid first. always start with the easiest diagnosis. thats my theory.

 

Ha! Fair enough, that's how I like to approach issues as well --> Ockham's Razor style.

The fluid looks ok, a nice tan, doesn't smell burnt or anything, level is good. From what I can tell nothing looks bent, the bolt on top of the pump is tight.

...this worries me that it's the pump. I walked over to the mechanic next door to my office and first thing he said after I explained the symptoms was "it's probably the pump." He's going to take a look later since it is STILL absolutely dumping outside

 

is it easy/hard in the same exact spots? map it out mentally along the wheels circle as you turn the wheel fill circles, does it coinside with a ujoints shape? might be jammed up with crud. not sure if there are any on the disco steering shaft, ive never looked... but i had a crown vic that had some build up of crud on the ujoint on the shaft, was very wierd, it was easy, then hard to steer in increments of almost exactly 1/4 revolution... it popped in my head a cross shape, and lo and behold, i looked at the ujoings and they had caked road crud on them. took some pb blaster and a brass bruss, cleaned em up, steering 100% back to normal.

 

Yes, the resistance is in the exact same spots.

I did notice that the U-joint close to (or at?) the pump was a little caked up with mud, but not sure enough to cause as drastic of a result as I'm feeling. I'll still give it a shot to clean it up to see if that remedies some of the symptoms. Thanks!

 

UPDATE : Mechanic checked it out today and gave me the diagnosis of 'I DUNNO?' Nothing is physically bent, or binding, so he guessed it's either the pump, or the gearbox, but he can't tell which.

Steering is still functioning, hasn't gotten worse, but surely hasn't gotten better. We're not going to drive it for a couple of days, then try flushing the system after the holiday.

 

time to hit the bone yard.

 

Did you give the joints a good clean and pb bath?