King Pin Bearings

Never replaced them, how does one check to see if they need replacing, and is it difficult? ('57 with Dana 25)

 

I think you disassemble and inspect. Once the condition of the parts is established, you use a fish scale to set the pre-load. I would expect to at least buy new seals and maybe a shim kit. Not a bad idea to go through the knuckles if it's never been done.

 

Tim, never done that before, meaning I have personally never attempted. Is it wise for me to try? I am mechanically inclined, but never tackled that particular job.

 

Not terribly hard to do. But you need to be serious about the details, such as properly shimming the clearance.

Most earlies have never had anyone care enough to do it. The bearing cups get "ripples" worn in them in the straight-ahead position and they can be a persistent source of Death Wobble.

Give it the time it deserves and do it right. You'll be glad you did.

You DO have a FSM, right?

 

YES. Neglect is the usual status quo.

 

This is another good video...

 

If you need to replace bearings, don't skimp by with the Chinese bearings. There are OK ones made in Taiwan, and Made in Japan are good, but Made in USA Timkens are best. You might not need to replace any. Most of the D25 and D27 axles I have pulled apart have had perfect bearings and races. Keep the shims with the respective caps in case you can put the knuckles back together as it was.
-Donny

 

Donny-I've never had one apart that the races weren't trashed. Of course that means the bearings are toast too.

 

I also have never taken one apart without at least one bearing being wasted. These axles are a labor of love as they take an incredible amount of time to get things just right. Many choose to go to a Dana 30 to avoid all of the hassle of working on these labor intensive axles.

 

Every 25 or 27 I have taken apart had severe grooves worn into the bearing cups.

 

I don't know what to say, but at least 6 front axles I've pulled down for heavy maintenence have had perfect races and bearings. Three of the above were known to me from new, and I had something to do with maintaining them, such as locking in the front hubs a time or two a month to circulate oil and changing out gear oil every couple years. I always ran 90W gear oil and kept up with weeps.
The only ones that had roached bearings were from the boneyards or old stuff that got dragged home.
-Donny

 

Maybe thats why I have only seen destroyed kingpin bearings. Its always someone else's garbage that I have resurrected!