It hasn't been enough that I spent four weekends cleaning out the mud and fixing the damage from the trip Down the Cheat.  There had to be something else to cap it off.  And so a couple days after buttoning things back up I returned from driving the Jeep and noticed when I got out a small drop of clean fluid on the driveway underneath the steering box...

Inspection revealed that the lock nut over the adjuster assembly (the end where the steering shaft goes into the box) was leaking slowly. 

It was a very slow leak but could not be ignored.  I read the service manual and learned that the oil seals can be replaced but a few special tools are required and some care is necessary to open it up on this end and replace the oil seals.  It would be a lot cheaper but as I didn't have the time or the inclination to take it apart, attempt a fix without all the special tools, then put it back together, I just went ahead and purchased a new box.  That makes it a matter of removing the old one, bolting in the new one, and following the procedure for bleeding the box after installation.

I found a remanufactured part at Napa Online.  Napa Power Steering Box 277601.  They are also for sale on Amazon.com if you prefer to have the part shipped to you.

 

Steering Box

Attributes:
Line Thread Size:M18X1.5
# of Mounting Holes:3
Input Shaft Diameter:3/4"
Output Shaft Diameter:1 1/4
# of Turns Lock to Lock:3 1/16
Type of Hose Ports:O Ring
Additional Contents:O Ring Kit
Pitman Arm Nut: 32~33mm/ 1 3/8"?
Pitman Arm puller: 1 5/16" opening

Aside from everyday tools, a pitman arm puller/remover is needed.  I found a couple that would work.  I caution that the one that I got from Napa was a fine tool but it was not wide enough to fit the Jeep pitman arm.  These listed below will work.

OTC 7314A Pitman Arm Puller This puller will handle nearly any Pitman arm job on passenger cars and light trucks. It features special forged jaws shaped to fit the job, ensuring a positive grip every time. Spread between jaw tips: 1-5/16"

I removed the steering box skid plate.  This was simply a matter of removing the nuts and bolt that held it to the steering box mounting point and front bumper.

Next I removed the pressure and return lines from the power steering pump reservoir and drained the fluid that came out into a catch basin.  I capped the openings in the pump.  Here's a drawing of the basic components.

6/29/07

I had a little trouble determining the size of the bolt that holds the pitman arm.  I measured it and determined it to be 33mm or 1 3/8" - both socket sizes were unavailable at Advance Auto so I grabbed one each 32mm, 34mm, 1 1/4", 1 1/2".  The best fit though tight was the 32mm so I used it to remove the pitman arm nut.  I was fortunate that it came free reasonably easily with a 1/2" long handled drive.  I laid on my back with my feet on the drivers wheel and pulled on the drive more or less as if I was standing up on the wheel.  The tire turned some until the steering wheel locked into the dash, then the nut came free.  I did soak it overnight with some penetrating oil.

I pushed the rubber dust seal up off the pitman arm shaft to make room for the pitman arm puller, fit the puller over the shaft, centering the pin on the puller pin into the depression on the pitman arm shaft.  I left the pitman arm shaft nut on the shaft a few turns to keep the puller from sliding off.  I tightened the puller, tapped the arm where it goes around the shaft, tightened the puller some more, tapped some more, tightened, tapped and soon the arm just eased off the shaft.  Again, I had soaked the shaft in penetrating oil overnight.

I made sure the wheels were straight before I removed the pitman arm from the shaft, and just let the arm hang free on the drag link. 

I put the nut on the new steering box together with the lock nut and dust seal and put it away for the night.

6/30/07

With the pitman arm out of the way, the rest of the job to remove the steering box went quickly.  Ted stayed with me to help.  We removed the bolt that holds the steering column to the steering box, the three bolts that hold the steering box to the frame. 

With the box supported by a jack stand I removed the pressure and return lines from the steering box and we were done (with removal).

Next we sorted out all the tools and pieces needed to install the new box.  I retrieved the rubber dust cover that slides over the pitman arm shaft, put some new grease on it, and slide it up onto the new steering box.  The new box came with one of the temporary covers broken off with the threaded portion in the hole.  This was a quick job for an easy-out.  There didn't seem to be any pieces of the plug missing that could have entered the pump so we continued.

I cleaned up all the fasteners and hoses.  I treated all the nuts and bolts as well as the line flare nuts with Anti-seize compound.  We put the steering box back in, after first installing new "O" rings and then attaching the lines to the box, and threading them back into place under the Jeep.  I taped the upper hose ends to prevent debris from getting inside.

We installed the steering box by attaching the steering column to the input shaft.  There's a flat spot that lines it up.  Then I got the frame bolt holes lined up and the bolts installed.  Then I installed the pitman arm.  Finally we reconnected the upper lines.

There are several documented ways to fill and bleed the steering box.  Since I did not have a catastrophic failure (steering gear parts circulating through the system) and the pump didn't fail, I felt I could top up the fluid and be done with it.  That still required that I fill the reservoir, cycle the steering wheel back and forth several times (all with the engine off and the front wheels off the ground to make it easier).  I repeated filling, cycling until no more fluid was required to fill the reservoir to the "cold" mark on the cover stick.

Then I turned on the Jeep and ran the steering back and forth a few more times and turned off the vehicle.  It took very little fluid.  I started the vehicle and let it run while cycling the steering back and forth with Ted watching for leaks.  We checked for leaks at the reservoir pressure and return, at the steering pump where the pressure and return lines connect, and the pump itself.  Dry as Death Valley in summer.

The steering gear made no untoward noises and the steering worked fine.  Mission complete!  The biggest part of this job was getting the correct puller, fluid, socket, the part itself.  Once the difficult job of sourcing and pulling was done, it was just six fasteners!

After the Jeep sat for several hours while I reinstalled my winch and refinished winch plate, I started it up and winched it up my driveway to tension onto the winch spool the cable that had been removed when I sent the winch out for service.  I let the Jeep run while I did this to keep the battery charging.  When it got to the top of the drive, I let it sit running while I finished wrapping the cable to store.  When I got done I noticed a small drop of something on the pavement precisely under the same spot as the leak I had done the job to fix!  I pulled the Jeep up to take a look and found the steering was hard!  Great.  All this and it still was bad!

I shut off the Jeep and looked at the fluid in the reservoir.  It had lots of little bubbles in it.  So I let it sit for about 10 minutes while I took a look at the service manual to see if I could diagnose the problem (from a selection of several defects listed for the pump or box).  All the symptoms I had pointed to two primary causes - not enough fluid or low tire pressure. 

Wanting the easy answer these choices sounded good but I remained skeptical.  I went back out and cycled the steering through several back and forth motions again.  The fluid went down a surprising amount but no more leaking showed.  I topped up the reservoir, started the Jeep and ran the steering back and forth some more. I shut off the Jeep and checked the fluid.  There were no bubbles and the fluid was staying up.  The steering felt fine though tighter than I remember.  But since I have been driving our Cherokee and Commander for the last several weeks during all this restoration work, I wondered if perhaps I was comparing the feel to a faulty memory.

I checked the tire pressure and found it was down by about 12psi on all four tires.  So the combination of air in the system and low tire pressure was indeed the likely cause of the stiff steering.  The manual was right.  I took the Jeep out to return some unused sockets and run some errands.  At each stop I checked the fluid.  No bubbles and only a slight drop in level.  When I got home I filled the reservoir up to the mark.  Should be good to go - finally...