Uh oh...just found a major leak under the power steering gear box. Looks like the pitman seal is trashed. How hard is this to replace, or, since it's an 85, would it be best to just replace the box? The gear box at Advanced is right around $99.

 

I bought one of those rebuilt ones from Advance, and have had good luck with it. Mine was doing the same thing, the bottom seal blew out. I am glad I replaced the whole thing, since the steering is much less sloppy with the rebuilt box.

 

Replacing the box isn't hard. I just did this over the weekend on a Saturday.

What you will need is a pitman arm puller, a tie rod end puller, a 33mm socket and preferably a 24" breaker bar. Various other sockets etc...

You should also drop the column and move it backwards when you get the steering coupler undone from the box. I found this a lot easier on my 1981. After you drop the Column, look down at the column to firewall seal, you will see a clamp looking at it from inside the truck. Loosen the clamp, and spray silicone lube on the seal, and you can move the column back. Makes it easier to replace the intermediate shaft as well.

Place a pan under the steering box as it will leak fluid. Remove both low and high pressure hoses at the box. you may have to unbolt the low pressure hose from the crossmember. Also you may want to place the truck on jackstands.

The box is heavy so be prepared for that.

If in doubt, get a repair manual with the proceedure.

There are components that you will need to torque to specified limits.

 

I've replaced the seal before. If you don't know what you're getting into, you're going to have a fun time.

You'll need needle nose or snap ring pliers, a big BIG adjustable wrench, a piece of 1 1/2'' exhaust pipe, and a pitman arm puller. Don't forget power steering fluid.

Undo the nut on the pitman shaft with the BIG adjustable wrench, and use the puller to break the pitman arm loose. Make sure that before you do this, the wheels are facing straight ahead and the steering wheel is two turns from either lock (on center).

Then, clean out around the snap ring on the bottom of the steering box. You'll want to get your needle nose or snap ring pliers up there and hook the snap ring and remove it from its groove.

Next, you'll want to make sure your PS pump is full of fluid. Crank the truck and turn the wheel side to side while someone else holds an oil catch pan up under the gearbox to catch the fluids (DO NOT GET POWER STEERING FLUID IN YOUR EYES). You'll want to throttle up the motor to around 1000 or 1200 rpm. Turn the steering wheel from lock to lock. You might have to refill the power steering pump with new fluid and repeat the procedure (I knew it was time to add fluid when the pump started to whine loudly). The seal will eventually come out, and it's two or three piece.

Follow the directions supplied with the new seal, and position the pieces in order on the steering shaft and slide them up into the box. You'll want the 1 1/2'' or so exhaust pipe to help you tap the seals up into the steering box with a hammer. Go easy, no hard hits, and go around the whole edge of the pipe to get the seals in there straight. Once all the pieces are up into the box (don't worry about going too far, but don't go way up above where the snap ring goes either) you'll want to put the snap ring into it's groove. Again, use needle nose or snap ring pliers.

Once that's done, put new power steering fluid in the system, make sure the steering wheel and wheels are straight ahead and on center, line the pitman arm up, put the nut on the steering shaft, and use that big wrench to tighten the nut up.

When I did the pitman arm nut, I had someone hold the wrench while I lay on the ground and did leg presses onto the wrench to tighten the nut down. This is partly so that it presses the pitman arm back onto the shaft, but also so you know the nut won't back off going down the road. You'd have to REALLY overtighten the pitman arm nut to strip it out or round it off. And I don't mean it as something that you can just do. You'll WORK to overtighten it enough to damage it. You'll feel when it stops.

Then, crank the truck with all new fluid, and turn the steering wheel from lock to lock while someone observes the steering box and the new seals. The pressure from the power steering pump will seat the seals in the correct position down on top of the snap ring. Then, check the fluid level again, and you're finished.

If you have all the tools and you know what you're getting into it's probably a 2 hour job at most. It took me half a day because I had to find something to help tap the seal up onto the steering shaft, and I had trouble getting a hold of the snap ring. It's important that you don't beat on the shaft itself as this could damage the box.

I just put the seal in my box along with a new power steering pump and I haven't leaked a drop yet.

It's also important to note, the seal kit (which includes a diagram with the position of all the seals, and the seals that go on the top of the steering box as well) is around 7 bucks from Advance, while a new steering box is much much more.

Good luck with the path you choose.

Also, don't forget to check your rag joint.

 

Thanks guys. I appreciate the input. Still undecided about changing the box or just the seals. Sounds like both are about the same in terms of time spent, and with a little slop in the wheel now it may just be time to change the whole box out. I'll update as soon as I get after it.

 

I changed out a box and the steering improvement was unbelievable. Drove like a new vehicle even though the ball joints and tie rod ends had 150K on them.

 

I've changed my steering box, also the pump at the same time.
Personally, for the cost involved, I wouldn't bother to replace only the seal if the box is the original.

You will get a better overall result swapping in a rebuilt unit........& not have to look at it again in a couple more years.

Just my thoughts

 

I have one of the Advance units in my truck, it's been just fine. You have to either flush the living hell out of your other components, or replace them. For the cost I opted to replace them. Pump, hi-pressure hose w/cooler assy, return line and box all went in at the same time. Makes for a cleaner job too.

 

The torque on the Pitman arm nut should be between 170-240 Ft lbs. So yes you have to really wrench on it and be muscular to do damage.

 

Online it says it's 144.99 at Advance, if I can find one for $99 that would be nice.

 

Here's a reman at parts geek for $93
1980-1997 Ford F150 Steering Gearbox - Steering - A1 Cardone 80-97 F150 Steering Gearbox - 5296-07003075 - PartsGeek

 

Ok guys, here's the update.
Got after this project as soon as Advance Auto opened at 9. Purchased the Pitman puller and rebuild kit. Had to stop on the way home to pick up PS fluid - forgot to get it.
Once I was under the truck, I started out by taking the big A$$ nut off the bottom of the pitman arm. It came off surprisingly easy, no way it had 140 lbs of torque. Anyway, once it was off, I saw that I had to pull the tie rod apart. HINT here for anyone who is going to do this themselves: get a tie rod puller and put the truck on jack stands. Do not to get this thing apart when it's on the ground. It'll come apart, but when it does you'd better be out of the way, which I luckily was, because it comes off at about 10000000 MPH.
The split ring is a bear to get out. The ring had turned around so that it was facing the front diff, so I had to use short pliers to get it out. I gave up after about an hour and sent my son in. He had it out, broken, but out in about 10 minutes
Several people noted that you need to mark the position of the steering gear. On my Ford, there are two distinct flat spots on the gear itself that point at the two flat spots on the gear housing so it's already marked. Luckily this was the case because marking the gear and case would have really been a pain with all the grease on them.
Ok, time to rebuild. I didn't get the piece of exhaust pipe that was recommended and opted for using a piece of PVC instead. It started to work, but then I found out that the diameter was too large to fit. Crap.
After messing with this for a while I ended up using a torx driver and just pushed the high pressure seal up in to the opening. You have to push hard to get the seal up past the split ring groove but once you get it started it goes in pretty easy.
Wrench the pitman back into place, attach the tie rods and everything is back together....but wait.
Remember when I said that the truck should be on jack stands? I made a huge error here, didn't jack the truck, and had a tough time getting the tie rods apart. I actually tapped the stud with a hammer - another bigger mistake - before I finally got the thing apart. Anyway, now the threads are misaligned. I just spent a couple hours outside with a thread restoring tool and file, but I cannot get the nut back on without the stud spinning on the ball. This is the passenger side tie rod where it connects to the driver side tie rod. If there's a way to remove the stud I'll do it! I'm tired of messing with it and want the truk put back together.

 

You shouldn't have had to mess with the tie rods or jack up the truck or do anything like that at all.

My truck was on all 4, with the wheels straight ahead, and the steering wheel on center.

Once the pitman arm was removed, you could just let it down to lay there. No messing with the ball joints or undoing the tie rods at all.

Also... if you look at the steering gear shaft where the pitman arm goes, there's a ton of tiny splines, then you got the bigger grooves that are cut wider and a little deeper. If the steering wheel and wheels are on center, then you should just have to slide the pitman arm back onto the shaft and tighten it up and be good. With the wide grooves and the small splines, with the wheels and steering wheel on center, it could only go on one way. I did have to fiddle with it and jostle it around a bit, but it went back on.

Rule of thumb, if it got in there or came out that way, it can go back in or come back out that way.

You also saw why I recommended exhaust pipe to tap it up in there nice and even... it had to be something narrow that could slip over the shaft like a sleeve so it could fit up in there without damaging the seals. It would be a bear if the metal seal with the grommet on it went in cantered like mine did.

Also, the 170-240 ft lbs of torque isn't to secure the nut on the pitman arm as much as it is to allow the pitman arm to be pressed onto the shaft by the nut. Mine came off easy as well.

Might have to get new tie-rod ends.

On my box, the seal that was bad was the little o-ring seal with the groove cut into it that had the coil spring inside of it. It had cracked and when the power steering pump put pressure to it, it opened up and blew PS fluid out.

 

Interesting...I tried initally to get the arm off without removing the tie rods, but it just wouldn't come out. Once I took the tie rod connector off it came right off, but that's where I ran into trouble.

 

Most likely it was bound up on the steering shaft somehow. I had the same trouble you did, but mine was when I was putting it on. It took some fidgeting to put it back on, but once it slipped onto the steering gear shaft, that was all it took and it was done.