2wd Steering / Suspension Issue

[NCheek]

Not really up to ***** on my terminology, but here goes...

Been hearing some noise and feeling some movement in the front end of my truck lately. Since I bought it over a year ago, the steering has had a pretty good amount of slack in it but I have just put up with it till now.

This evening, I jacked up each of the front wheels to check on the bearings and such, and ended up snugging up the nuts on both hubs to tighten everything up. All was good until I noticed that I still had some play in the driver's side wheel. Upon further inspection, the entire wheel and steering knuckle could move up and down about 1/2" where it attached to the I-beam part of the axle.

I'm not sure exactly haw it is assembled and I don't have my manual with me at school, so my questions are: what most likely is the problem, and how difficult of a fix am I looking at? I really need to replace everything steering / suspension related, but this is the priority.

Thanks guys.

 

[david85]

99% sure You have a collapsed vertical load bushing on your king pin(s).

The part is essensially a thrust bearing but instead of rollers, it has a bronze bushing in between two hardended steel washers. Then there is the stamped steel shell on the outside to hold them all together (by now it could be a mangled mess). The king pins require greasing at regular intervals to keep things working properly. If its not greased properly it wears away because that part is holding the full weight of the truck on it. It might also be possible the the thrust bearing was never installed, but I think thats unlikely.

Mine had that problem on both sides and caused mild stiffness in the steering. Its not enough to notice it in the wheel except that the truck can resist light input at the wheel when tracking strait, so you have to push the wheel further to get the response. In practice if feels a lot like loose steering, even though its caused by stiffness. The truck may also fail to return center after comming out of a turn and track where ever you put the wheel (in a wide turn or dead strait). The result is the truck needs constant correcting to keep it strait and feels more like a container ship than a wheeled vehicle.

Sound like yours?


Assuming thats whats wrong:

To fix this you need to get a king pin and bushing kit (all in one kit). Cost me about $100 for all the parts. The old king pin has to be driven out and the knuckle will have press in brass bushings that also have to be replaced. The bushings in the knuckle will have to be machined to match the king pin (automotive machine shop has to do it). You could also get the lighter duty version that has nylon bushing and don't need machining, but they won't last nearly as long.

If all that wasn't enough, the old king pins are usually very hard to remove. You can try and use a BFH and a lot of heat, but I have a 50 ton shop press that I used. Dropped the I beam with the radius arm and spring still attached and pressed it out. Took about 10 tons of force.....

The good news is that if you do this job, you will probably never have to do it ever again because king pins easily out last ball joints.

 

[NCheek]

99% sure You have a collapsed vertical load bushing on your king pin(s).

The part is essensially a thrust bearing but instead of rollers, it has a bronze bushing in between two hardended steel washers. Then there is the stamped steel shell on the outside to hold them all together (by now it could be a mangled mess). The king pins require greasing at regular intervals to keep things working properly. If its not greased properly it wears away because that part is holding the full weight of the truck on it. It might also be possible the the thrust bearing was never installed, but I think thats unlikely.

Mine had that problem on both sides and caused mild stiffness in the steering. Its not enough to notice it in the wheel except that the truck can resist light input at the wheel when tracking strait, so you have to push the wheel further to get the response. In practice if feels a lot like loose steering, even though its caused by stiffness. The truck may also fail to return center after comming out of a turn and track where ever you put the wheel (in a wide turn or dead strait). The result is the truck needs constant correcting to keep it strait and feels more like a container ship than a wheeled vehicle.

Sound like yours?


Assuming thats whats wrong:

To fix this you need to get a king pin and bushing kit (all in one kit). Cost me about $100 for all the parts. The old king pin has to be driven out and the knuckle will have press in brass bushings that also have to be replaced. The bushings in the knuckle will have to be machined to match the king pin (automotive machine shop has to do it). You could also get the lighter duty version that has nylon bushing and don't need machining, but they won't last nearly as long.

If all that wasn't enough, the old king pins are usually very hard to remove. You can try and use a BFH and a lot of heat, but I have a 50 ton shop press that I used. Dropped the I beam with the radius arm and spring still attached and pressed it out. Took about 10 tons of force.....

The good news is that if you do this job, you will probably never have to do it ever again because king pins easily out last ball joints.

Well, Sounds about right as far as symptoms go, and I do have a 20 ton press, so maybe that will do... I've got a feeling this might be my spring break project. I assume ford is the best place to get the parts for this one, and while I'm at it I'll probably replace all the "wear parts" up front.

Thanks for the help, but I'll probably have more questions to come.

 

[Todd C]

Yeah, what David85 said... When I did mine, I couldn't budge the pins with a small sledge and drive pin. I pulled the axle and took it to a machine shop and had them remove and install the new king pins and bushings. It's been a few years, but I think it ran about $250 plus parts ($50?)
Todd

 

[david85]

I got aftermarket pins. They were a well known brand but I can't recall the exact name....

Since I was able to get my pins out in my shop, all I had to do was drop of the pin, bushings and knuckle at the machine shop. First time he was in a good mood and undercharged me for install and borring of the bushings ($20 cash). It was nearly a year before I had the stomach to attempt the other side. That time the machining fee was the standard rate of about $40.

My only regrets are waiting so long to do the work, and NOT using the press the first time around. It makes the whole job so much easier. 20 tons should be enough to force it out.

So far those are the only parts I've had to replace on my front end. All the bal joints on the tie rod are still tight as well as the rag link, radius arm bushings and pivot bushings. Only remaining complaint is the low caster angle on the steering. Would be nice if it came back to center a little more quickly. But it was still night and day difference after I replaced the second king pin. Once up to 60 MPH, its VERY responsive and I can control the truck with the tip of my finger. Much more enjoyable to drive.

 

[NCheek]

I was looking at rockauto.com and they have a Spicer "kingpin kit" listed for $60.79, is that what I need and is that about the right price?

 

[david85]

I just looked on the website and yes, that is the kit you want. I paid more becuase I am in canada and prices are higher dollar for dollar up here. I think mine was spicer too.

 

[NCheek]

when you say it was a year after the first one that you mustered the courage to do the second, was it really that bad? And while I have the truck down, should I do both sides?

 

[david85]

The first time I didn't try the shop press. That was just plain stupid of me. Instead I heated the beam up almost cherry read and wailed on the pin with a steel drift to get it out. Took a good 2 days just to get everything for one side apart. Definately the wrong way to go about it! The second time I was done the teardown in about 3-4 fairly relaxed hours.

Knowing what I know now, I would not hesitate to do both sides at once. Its really easy if you have access to a press to force the pin out. Much safer for you and the truck that way....

The only real variable is how long the parts might be at the machine shop. But in my case there was only one in town so I had no choice but to wait a few days. Call ahead and ask what their schedule is like before tearing down the front end.

You can drive the old lock bolt, king pin and bushings out yourself and just take the spindle (with hub and bearings removed), new king pin, and bushings to the machinist. He will install the bushings and bore them to match the pin for you. After that its really easy and fast to put everything back together. There is a minimum of parts on the front end of these trucks.

When your done grease the living hell out of it!!

 

[NCheek]

Now that I am home and have my circa 1991 Haynes manual, it doesn't say anything about needing to have parts machined... Why wouldn't they sell you parts that fit in the first place?

 

[david85]

It makes for a tighter, longer lasting fit if the parts are line borred to match the pin. I'm not supprised the haynes manual left out the info about needing machining for the brass versions.

Ball joints eliminate all of this, and thats why they went with a ball joint knuckle on the F250s in 1987 and up. Kingpins are stronger and last longer though.

 

[NCheek]

But if it will fit out of the box, how will machining it tighten it up? Am I missing something?

I do understand that the better initial fit, the longer the service life!

 

[david85]

But if it will fit out of the box, how will machining it tighten it up? Am I missing something?

I do understand that the better initial fit, the longer the service life!

OK, I get what you are asking.

the outside if the bushings are steel backed and those fit the bore in the knuckle right out of the box. All you have to do is carefully drive them in with a hammer and a socket (like a wheel bearing race).

The inside of the bushings (the brass side that is what the pin slides on), is too tight for the pin to actually fit, so you could call it undersized. Thats what gets machined to match the pin after both bushings are installed.

 

[NCheek]

Ok, that makes sense. Now to get the parts and find a reputable machine shop...