Kingpin Replacement

[bpossel]

Hi All,

I just finished installing a new king pin alone with replacing the upper alignment pin, bushings, etc and the lower trunnion.  When I tighten the bottom king pin nut, the steering knuckle will not move.  Thus, I need to replace the lower thrust washer with a thinner one.

Rather than removing the pin and all the pieces again, I want to simply remove the lower king pin nut (after jacking up on the lower control arm under the coil spring).  Then lower the control arm, thus separating the pin out of the lower trunnion.  This will give me access to replace the washer.

Question … does anyone see any issue with replacing the thrust washer this way?  I am a little concerned that I will not get the lower part of the pin lined up again with the lower trunnion.  Then as I raise the suspension, is there any chance of bending the pin if it enters the lower trunnion slightly off center?

Any advice for making this job of replacing the thrust washer easier?  Will the above work?

Thanks,
Bob


bpossel
Memphis, TN.
1971 280SL
1997 E320

[Benz Dr.]

Don't worry. It will all line up again. Choose a washer that allows free movement when the bottom nut is fully tightened.

Dan Caron's
 SL Barn
benzbarn@ebtech.net
 slbarn.mbz.org

[BHap]

Bob - sorry I don't have an answer for you - but I will pose a slightly different question - is there a way to "mock up" the kingpin prior to installation to determine which thrust washer is correct?  I was just going to ask this question when I saw this one - so maybe we can kill two birds with one post....  maybe someone can explain the proceedure to both of us....  thanks

Bob Happe
Pittsburgh, PA
1970 280 SL ~ 53,000 miles

[bpossel]

Thanks Dan for the reply post.  This will save me lots of time and mostly concern of making sure its done the right way!

Bob H. - To answer your question...  YES!.  What I should have done is connect the lower trunnion to the steering knuckle, with new king pin installed, when it was on the bench.  You can have all the pieces connected and then tighten the lower king pin nut.  Then try to move the lower trunnion unit on the pin.  For some reason....? I didnt do this.

Good Luck!
Bob

bpossel
Memphis, TN.
1971 280SL
1997 E320

[bpossel]

Dan, Joe A,

Thanks for all your replies, posts, etc. regarding the replacement of my king pin.  Just finished and all looks and seems to work great.  It only took a few minutes to separate the pin from the lower steering knuckle housing and replace the thrust washer with a thinner one.  The new king pin kit came with 3 different thicknesses.  I ended up having to use the thinnest one.  With this, I was able to completely tighten the king pin nut and have the steering knuckle still turn freely.

Now I need to get the car aligned...

Thanks again!
Bob

bpossel
Memphis, TN.
1971 280SL
1997 E320

[erickmarciano]

replaced my also and I used the thinest washer and when I fully tighten the king pin nut It wont turn , so I backed up the nut a little. is this safe ?

1971 280sl
1962 VW
1954 Allstate vespa
1958 gs150 vespa
1962 gs160 vespa

[bpossel]

Erick,

From what Joe and Dan have told me, the king pin nut must be tight.  Not sure what you should do now, if you are using the thinnest washer and still are not able to tighten the nut and have the steering knuckle turn freely?

Joe, Dan, others, any advice for Erick?
Bob

bpossel
Memphis, TN.
1971 280SL
1997 E320

[mbzse]

quote:Bob wrote
From what Joe and Dan have told me, the king pin nut must be tight.  ../..Joe, Dan, others, any advice for Erick?

_Yes_ this nut must be tight!!. It locks the conical pin into the lower knuckle - forms the stability for the front wheel.

Like for almost everything on our 60's Mercedes, there is a spec in the manual... Play should be 0,05 to 0,1mm up/down for the steering spindle. Very little, measure with dial gauge.
Max allowed is 0,5mm.

To obtain the correct play, fit washers, tighten nut to correct torque (90 Nm)
and measure. Compare to spec. Then, if necessary, grind the sides of a washer to the thickness you need, fit this, tighten and measure etc. until you have it right.

Takes some effort, but, if this is not done correctly the steering on the car will not "feel right".

BTW, a good conversion tool Imperial/metric can be found on:
http://www.processassociates.com/process/convert/cf_all.htm

/Hans in Stockholm

[roadsterdude]

I am in the process of re-fitting my new kingpins and I am having the same trouble with the compensating washer.  When using the thinnest washer the steering locks up as I approach 60-65 ft lb of torque.  I tried grinding the washer and it still freezes.  I installed it with NO compensating washer and it turns, but still seems very tight at 65 ft lbs.  Can i install this with no washer in the lower pivot?  What should I do now?  I am stopping until I get some advice, because this is my steering (which can be very important)  This job has been one issue after another.

[w113dude]

I am in the process of re-fitting my new kingpins and I am having the same trouble with the compensating washer.  When using the thinnest washer the steering locks up as I approach 60-65 ft lb of torque.  I tried grinding the washer and it still freezes.  I installed it with NO compensating washer and it turns, but still seems very tight at 65 ft lbs.  Can i install this with no washer in the lower pivot?  What should I do now?  I am stopping until I get some advice, because this is my steering (which can be very important)  This job has been one issue after another.

I had exact same issue while back, most likely you have crushed the pin that is on the of the housing where the kingpin goes in, take the top two washers off and you'll see the pin has mushroomed, what I did was using a dermal tool I grinded off  what was left of the pin, put them all back together with thinest compensating washer and worked perfect, from what I have seen on previous post those pins are not that important.

[Benz Dr.]

I always install the bottom pivot on the lower control arm with the upper pivot and king pin in place before I start with instaling washers. The weight of the car will easily compress the spring so that you can start the nut.

I've seen cases where the king pin bushings weren't installed correctly and they were a bit proud of the housing surface. It takes very little to make the whole assembly bind up when torqued down. Done correctly, the bushing hould have two small notches so that grease can escape to lubricate the thrust washers.

[ja17]

Yes, go back and check to make sure the locating pin at the top is still in place as Eric has suggested.