Author Topic: King pins - that wasn't so bad  (Read 6611 times)

twistedtree

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King pins - that wasn't so bad
« on: May 16, 2010, 20:20:26 »
I just finished replacing the king pin and bushings on one side of my car.  It wasn't a hard job at all, provided you have a press and reamer.  I've had the press for years, but bought the reamer just for this job.  It's adjustable between 25/32 and 27/32 which covers the 20mm nominal bore of the bushings.  The reamer cost $12, plus as much again for shipping, but was still inexpensive all told.

I'd say the hardest part was getting the old bushing out.  Each bushing blocks access for pressing out the other, so there is no way to remove them one at a time as you ideally would like.  The only way I could see to do it was to press one bushing down into the spindle and up against the other bushing, then continue to press them both out the bottom.  It worked, but took a fair amount of force.  After getting them out, I realized that the bore in the spindle necks down a tiny bit between the two bushing, so forcing the upper bushing through there takes some effort.  It's a good thing bronze is soft.  If anyone has found a better way to press them out I'd love to hear about.

After cleaning things up, I pressed the new bushings in, one from each end.  That part was straight forward.

Then on to the reaming.  As expected pressing in the bushings tightened them up and the king pins would no longer fit in the bushings, hence the need for reaming.  After figuring out how the reamer adjustment worked, it was pretty easy to adjust it to the bushing and lightly ream it out.  Of course you want to take away material slowly and carefully since you can't put it back on if you take too much.  It only took 10 minutes or so and I had a perfect fit, free from binding and free from play.

The king pin kit comes with three different thickness bottom end washers to set the end play.  I tried the middle one and found things still too loose, so I used the thickest.

That's the hard part, and it wasn't so hard after all.  Tomorrow I'll put the suspension back together and start on the other side.  I can certainly understand the attraction to sending the press and ream job to a machine shop, and if you don't have a press that's the only course.  Don't try to hammer the bushings out or in - you will just ruin them and/or the spindle.  But the reaming part was really a piece of cake with the right tool, and the tool is a whopping $12.
Peter Hayden
1964 MB 230SL
1970 MB 280SL
2011 BMW 550xi

w113dude

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Re: King pins - that wasn't so bad
« Reply #1 on: May 17, 2010, 01:19:16 »
Good for you, you sure make it sound easy!

ja17

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Re: King pins - that wasn't so bad
« Reply #2 on: May 17, 2010, 03:01:39 »
Hello,

Good job!   Cutting a vertical slot in the old bronze busing with a hack saw will allow the bushings to collapse a bit for easy removal.
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback

dseretakis

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Re: King pins - that wasn't so bad
« Reply #3 on: May 19, 2010, 13:14:51 »
Twistedtree, can you tell us a little more about the reamer?  Where did you buy it?  How does it work?

twistedtree

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Peter Hayden
1964 MB 230SL
1970 MB 280SL
2011 BMW 550xi

JamesL

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Re: King pins - that wasn't so bad
« Reply #5 on: May 25, 2010, 11:32:14 »
I REALLY hate those people popping up on their own websites and talking to me

Makes browsing at work even higher risk
James L
Oct69 RHD 280 in DB906 with cognac leather

twistedtree

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Re: King pins - that wasn't so bad
« Reply #6 on: May 25, 2010, 19:42:14 »
Yes, I agree.  It's very annoying, and more and more prevalent on web sites these days.
Peter Hayden
1964 MB 230SL
1970 MB 280SL
2011 BMW 550xi

tel76

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Re: King pins - that wasn't so bad
« Reply #7 on: May 25, 2010, 20:55:39 »
The reamer that you used did not have the guide/pilot,how did you get the top bush to align with the bottom?
Eric

twistedtree

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Re: King pins - that wasn't so bad
« Reply #8 on: May 26, 2010, 16:05:37 »
It self-aligned, so the speak.   There is enough length in each bushing that it would take an effort to not ream it on center.  Admittedly the approach I took assumes that the spindle has a straight bore and that the bushings have concentric outer and inner surfaces.

I'm comfortable that they are aligned in my case since I was able to slide the king pin in from either end and it went right into the second bushing without any interference.  I don't think that would be the case if they were not aligned.

I've done this exactly once, so I can't say if I got lucky or if it's a reliable procedure.  Perhaps others who have done this more can comment too.
Peter Hayden
1964 MB 230SL
1970 MB 280SL
2011 BMW 550xi

stickandrudderman

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Re: King pins - that wasn't so bad
« Reply #9 on: May 26, 2010, 16:54:08 »
It's very important to use a reamer that is long enough to cover both bushes at the same time. Without common centres you're going to get wear very quickly.
Cutting the slot in the old bush is the best way to remove them.

Mark280SL

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Re: King pins - that wasn't so bad
« Reply #10 on: May 27, 2010, 01:58:47 »
Well done! how much of a difference do you note after the job was complete? what is the before and after like when driving the car?

I just finished replacing the king pin and bushings on one side of my car.  It wasn't a hard job at all, provided you have a press and reamer.
« Last Edit: May 28, 2010, 10:14:26 by Peter van Es »
Mark