Decided to tackle the aging power steering system on my 2004 D2. 230,000k. Symptoms prior included minor whining when taking sharp turns. Minor ps fluid loss.

I saved the ps gearbox from my grey D2. That gearbox had around 170,000. Worked fine when the grey truck was running. But while i had it out I decided to send it out and have it rebuilt. Figured when the day came to update the power steering system on my white D2 all I'd have to do is swap out the gearbox for the rebuilt unit, plus throw in a new ps pump.

So this weekend I took the truck apart. Replaced some pullies, swapped out the gearbox for the rebuilt box and installed a new ps pump. Also swapped out the old ps hoses that connect to the reservoir for the ones I saved from my old truck as well as the reservoir itself. These parts were all new as of 2013 when I updated the ps system on my grey truck. Next I replaced the serp belt. The old belt has cracking.

Following reassembly I installed Prestone ps fluid. 3 quarts give or take. Turned the truck on for 30 seconds then back off then stopped off fluid. Did this afew times. Next I turned the truck back on and turned the steering wheel in either direction a couple times then dropped off the fluid. Took the truck for a test drive. Constant whining and rough steering. Next I tried Disco Mike's method. Using a hand pump I sucked out all the fluid from the reservoir and added in fresh fluid. Did this 4 times. Another test drive and still whining and somewhat rough steering. Next I opened the cap and left it open for an hour. Then I had my girl start the truck while I opened the bleed valve on the gearbox. As she slowly turned the steering wheel I kept the bleed valve slightly opened so to allow steady stream of ps fluid to seep out. All awhile paying close attention to fluid level in the reservoir. I had her rotate the steering wheel slowly back and fourth while I left the bleed valve open. Then closed it back up, topped off the reservoir.

Still some minor whining and the steering feels not right as you rotate the steering wheel sometimes it feels super smooth like you can rotate the wheel effortlessly but as you continue to rotate you can feel rough patches where you kinda have to fight it to steer.

Not sure where j went wrong here or maybe the gearbox rebuild was done incorrectly by the shop. Looking for suggestions.

 

Could be the pre-load on the PS Gearbox.

 

What exactly does this mean? What steps should I take to make the system perform as it should?

 

You loosen the nut ontop of the box, and with a torx/allen you turn it in very small increments, tighten & then test side to side to see if you’ve corrected it.

There was a decent write up on it a while back. RRC/D/D90/D2 = all the same.

 

I've done some reading up on the gearbox preload adjustment. My understanding is that if you have really loose or vague steering then the possible solution would be to raise front wheels off the ground, use a 18 socket or wrench to loosen the nut that has a hex inside. Next use a hex tool to ever so slightly turn the hex screw. Then test the steering wheel to see of steering is more responsive.

My symptoms are different:

1) constant low tone whining noise from power steering system. Cant determine if the pump or the gearbox is making the noise. Sound is less noticeable at high speeds.

2) steering wheel can be turned counter clockwise easily with one hand and only has minor resistance.

3) steering wheel can be turned clockwise but there is noticeable amount of resistance and two hands work best.


Prior to working on the power steering system I made sure the wheels were forward facing. I wont say they were perfect precision but straight as much as I got get it. Made sure steering wheel was level and front wheels looked front facing.

With that said is it possible that when I connected the steering shaft to the gearbox that I misaligned things? I noticed while inserting the shaft into the gearbox that there is some minor play in the steering shaft. Like you can rotate the shaft by hand in either direction a bit. Is there a precision line up spot on the shaft that is suppose to be lined up with specific spot on the gearbox?

What about the drop arm on the steering gearbox? Does that have to be positioned in a specific alignment on the drag link?

 

I replaced my PS pump a couple months, i barely drive it, and I get a whine all the time now. The steering fine, smooth, easy, but there is a whine. I run a couple bottles of fluid through it. I think it is important to go lock to lock on this. I ran a hose from the bleed valve to the reservoir so I was not wasting fluid and purged it for a while.
I still have the whine, I am a bit at a loss, maybe just need to keep bleeding?

 

Did you use a genuine ps pump or aftermarket? I went with a aftermarket because Rimmerbros did not have the genuine in stock and I was impatient.

Good tip on feeding 1/4th hose from bleed valve and directly to the reservoir. At this point however I feel like I can bleed the system all day and it wont make a difference.

 

What kind of Prestone PS fluid did you use? I've always been told to use the European green PS fluid on our Discos which is actually central hydraulic fluid (CHF).

 

I used the regular prestone, seemed to be the consensus on several sites.
The pump is an aftermarket from Amazon, I usually assume that i am the problem, not the part. i was hoping to get some insight on how much bleeding typically needs to occur to get it right, but maybe it is the pump?

 

I also used prestone. I did purchase the lr genuine ps fluid but currently only have 1 quart so decided to throw in the cheap stuff until I get 2 more quarts then do another flush down the road.