King pin install

[HarryBiron093]

Guys,

I am redoing the king pins on an RD 688 with a 20,000 lb front. I bought all Mack parts and everything thing went back together perfect until I went to grease the lower knuckle. As soon as I put grease to it it pushes the pins up wedging it. I have pulled it apart thinking I had the lip seal in upside down up it isn’t that. I have the slots lined up so grease should run right up the bushing. Any one seen this before ? 

Edited 18 hours ago by HarryBiron093

[Joey Mack]

Im not sure what 'pins' you describe.  The tapered king pin set up is excelent.  Did you seat the king pin up into axle beam with a sledge and a jack on the bottom of the pin ? You also need to pre lube the thrust bearing and you use the lower nut to set the bearing. The front ends weight is on the thrust bearing.  

[HarryBiron093]

Yes sir followed the procedure from start to finish. Put the jack under the pin and put it up into the knuckle then hit the sledge down. Pre lubed pin and packed bearing. Set the upper knuckle to .0015 and with the pressure off I have .0020 which is what the book wanted. Then I go to grease it and the bronze bushing pushes up and locks the whole knuckle solid. I talked to a tech and he has had this happen, he said he ran the truck for a few days on what he called a break in period and then it took grease fine after that. Thoughts ? 

[Joey Mack]

ok.. so its the bushing and not the ''pins'' as you stated. I was confused. is it the upper bushing, or the lower one coming up to the axle beam?

did you check fitment of the bushing in to the knuckle bore? 

That bushing should have had to be pressed in or driven in with a proper bushing driver.

Are you using a Keyser kit with the coiled type of bushings?

[Joey Mack]

dis regard the Keyser question, I see you posted a bronze bushing

[HarryBiron093]

Checked bushing on king pin before install it was nice and snug. Bushing pounded in nice and tight. Certainly didn’t feel loose by any means. The grease gun stops like there’s pressure, similar to when you have a pin that won’t take grease. Just lower bushing the top one greased perfect. Both sides lower bushing have the same symptoms. 

[HarryS]

Is the bushing hole lined up with the spindle hole?

[mechohaulic]

2 hours ago, HarryBiron093 said:

Checked bushing on king pin before install it was nice and snug. Bushing pounded in nice and tight. Certainly didn’t feel loose by any means. The grease gun stops like there’s pressure, similar to when you have a pin that won’t take grease. Just lower bushing the top one greased perfect. Both sides lower bushing have the same symptoms. 

way I'm reading ; project done by book standards= excellent. my question would be the statement" bushing on king pin BEFORE install nice /snug. bushing POUNDED in nice /tight. possibly the install may have "shrunk" the bushing enough not being noticed when pin installed since a jack was used . the comment by a tech == run it a few days then it's ok would be the pin corrected the tight flared over bushing ????