Author Topic: Kingpin install  (Read 4574 times)

Jazn

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Kingpin install
« on: November 20, 2006, 14:35:43 »
I just had the brass sleeves pressed into my spindles and it seems the new kingpin is a tight fit into the new sleeves.  Is this normal?  Should I have the kingpin pressed into the spindle?  
Thanks in advance.
Jason

Jazn

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Re: Kingpin install
« Reply #1 on: November 20, 2006, 15:14:12 »
Okay, just did a search on this subject, I see they have to get reamed.  How much clearance do you need between the kingpin and sleeve?  Or should the machine shop be able to do this?

BHap

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Re: Kingpin install
« Reply #2 on: November 21, 2006, 09:16:49 »
Radial play between kingpin and bearing bushings:

the specified radial play is:

installation play:  .020 - .062
max perm. play    .3

fyi  end play of kingpin  installation: .05 - .1
                          max perm play   .5

the end play is trial and error...  fit together, torque, sand compensating washer, repeat...  you want to be able to torque the lower nut without having the kingpin "drag"....

i would let the machine shop ream the bushing...  you can do the compensating washer without too much trouble....

Bob Happe
Pittsburgh, Pa
1970 280SL, white/black 4 speed
Bob Happe
Pittsburgh, Pa
1970 280SL, white/black 4 speed

Jazn

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Re: Kingpin install
« Reply #3 on: December 04, 2006, 14:01:41 »
quote:
Originally posted by BHap

Radial play between kingpin and bearing bushings:

the specified radial play is:

installation play:  .020 - .062
max perm. play    .3

fyi  end play of kingpin  installation: .05 - .1
                          max perm play   .5

the end play is trial and error...  fit together, torque, sand compensating washer, repeat...  you want to be able to torque the lower nut without having the kingpin "drag"....

i would let the machine shop ream the bushing...  you can do the compensating washer without too much trouble....

Bob Happe
Pittsburgh, Pa
1970 280SL, white/black 4 speed


Bob
Forgive my ignorance, how/where are you measuring the endplay?
I'm finally at that stage.  Thanks
Jason

BHap

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Re: Kingpin install
« Reply #4 on: December 04, 2006, 15:44:10 »
End play is measured between kingpin and spindle - up and down when the kingpin is installed in the spindle and the lower nut is torqued.  The spindle should turn freely but not have too much play.  My kingpin kit came with three different size lower compensating washers.  Once you find the washer that allows you to almost torque the bottom nut to spec before the spindle starts to drag on the kingpin, you can sand the lower compensating washer to get an exact fit. It is a little trial and error, but if you leave any "drag" in the spindle/kingpin pivot, your steering will feel dead and the wheel will not return to center as it should.  You can do this all without installing on the car.  Once you can torque the lower nut to spec and still have the spindle turn freely, you're there....

Bob Happe
Pittsburgh, Pa
1970 280SL, white/black 4 speed
Bob Happe
Pittsburgh, Pa
1970 280SL, white/black 4 speed

BHap

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Re: Kingpin install
« Reply #5 on: December 04, 2006, 16:03:18 »
the torque for the lower nut is 9 mkp which is about  7.233 x 9 = 65.1 ft lbs...  because the kingpin is tapered, torque and endplay are related...  you need to have endplay (spinle/steering knuckle turn freely on kingpin) when you torque lower nut to 65 ft lbs.  if it drags before you get to 65, take it apart and either try a smaller compensating washer, or sand the compensating washer to make it thinner....  if you torque to 65 and it spins freely, measure end play to be sure it is not too much - if it is - use bigger compensating washer and repeat.... it will take a few iterations to get it right...  I backed the nut off until it was flush with the bottom of the kingpin and gave it a sharp blow with a big hammer to get it apart between tries...  be patient, have fun....

Bob Happe
Pittsburgh, Pa
1970 280SL, white/black 4 speed
Bob Happe
Pittsburgh, Pa
1970 280SL, white/black 4 speed

Jazn

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Re: Kingpin install
« Reply #6 on: December 04, 2006, 19:32:12 »
quote:
Originally posted by BHap

the torque for the lower nut is 9 mkp which is about  7.233 x 9 = 65.1 ft lbs...  because the kingpin is tapered, torque and endplay are related...  you need to have endplay (spinle/steering knuckle turn freely on kingpin) when you torque lower nut to 65 ft lbs.  if it drags before you get to 65, take it apart and either try a smaller compensating washer, or sand the compensating washer to make it thinner....  if you torque to 65 and it spins freely, measure end play to be sure it is not too much - if it is - use bigger compensating washer and repeat.... it will take a few iterations to get it right...  I backed the nut off until it was flush with the bottom of the kingpin and gave it a sharp blow with a big hammer to get it apart between tries...  be patient, have fun....

Bob Happe
Pittsburgh, Pa
1970 280SL, white/black 4 speed


Okay, I get it now, only problem is, without a compensating washer on the bottom the kingpin fit is still pretty tight, it moves but it's tight.  Should it move more freely?  Should I grease it up good?
Thanks.