Lower a arm inner bushing replacement

[guentersundag]

My manual does not include the proper re installation of the lower inner screw in bushings.  Need help.  Thanks a lot

[jameshoward]

Could you post a shot of the bushing you mean, to be clear?

[glenn]

It's a fun job!!!  And you get to do a wheel alignment as a bonus. ...

[guentersundag]

Could you post a shot of the bushing you mean, to be clear?

[glenn]

Where is the 1/2 inch of grease and mud?  Never seen such pristine parts in the under carriage!

[guentersundag]

Thank you,

The whole car is like it, getting a lot of cleaning and regular maintenance.  Any idea where to find the recommended installation of the bushings?

Gunter

[Dash808]

Hopefully this can be of some help:

A diagram:

http://www.sls-hh-shop.de/index.php/language/en/cat/c3_Mercedes-Benz-230-280SL--R113-.html/XTCsid/724fcb492eab4185dfb4206d8d6196ac#cat_67_position_30_prod_0

And a thread.  Jim Villers talks a little about install down at the bottom of the page:

http://www.sl113.org/forums/index.php?topic=3759.0

[bpossel]

Hello Gunter,

Check out my website (Jan12 & April 13) for some pics of the parts and area...
http://picasaweb.google.com/mercedes280sl

What you need to do is to have a hydraulic jack under the inner arm, remove the 4 nuts & bolts and carefully lower the inner arm down.  This is a tough job as the spring is under a lot of tension!  Once the arm is lowered down, you unscrew each end nut/cap and install the new rubber bushings.  These bushings are simply a rubber "ring" that helps to keep the grease in (sort of) and the dirt out.  Make sure to screw each end in uniformly.  With all of the pieces cleaned up and slightly lubed for easier installation, you will see that each end cap/nut screws onto the pivot bolt and also screws into the arm itself.  Make sure to start each end with your hands.  If all is correct, starting by hand and threading these end caps in is very easy!  If all correct, the ends turns (pivot) like butter.  If you feel resistance, then you may need either new end caps or new pivot bolt.  When I did mine last year as part of my resto, I had to buy new end caps as the threads were worn and there was resistance on the worn pieces.

The hard part is to re-install the arm back in place with the 4 bolts.  What will happen is that as you are jacking up the arm (lots of tension/resistance with the spring) the outer swing of the king pin will want to push outward.  The 4 bolts that hold the inner arm in place have virtually no room for play in their respective holes.  You need to perfectly line up the inner arm with the pivot so that the bolts slide through their holes.  You can slightly tap them down, but if you need to hammer with force, you do not have it lined up correctly.  To me, this was the hardest part of the job! Make sure to use new lock washers.  One thing that helps to line the holes up is to buy a couple of long bolts (exact same dimension as original) and to grind off the threads and make the ends slightly pointed.  This helps to guide the arm in place so you can then install 2 original bolts and then tap out the other bolts that you made and then install the 2 remaining original bolts.

If anyone else can help with more advice, instructions, please jump in ....
Good Luck,
Bob

[thelews]

Where is the 1/2 inch of grease and mud?  Never seen such pristine parts in the under carriage!

[Joe]

The biggest problem you will have is aligning the holes while lifting the A-frame. When you lift it, there is nothing forcing it to line up with where it will ultimately be, and the holes can be so far apart that it is dangerous to try to force the jack to move sideways so as to align them.
You certainly won't want to put extravagent force on it sideways because of the danger of it popping loose and shooting the spring in your direction. I had some threaded rod, about 12" long and a half inch in diameter that facilitated the installation. I started the lift and then put the rod through one of the holes in both the lower part and the upper part. As I lifted, I finger-tightened the nuts so as to keep the parts from flying apart and to provide a "path" for the A-frame to follow. Once the parts were together, a screwdriver or pry-bar was used to perfectly align the holes for the insertion of the bolts.
This is similar to the method Bob described, but probably takes less time. You can use about any diameter of threaded rod, or even a long bolt, if one long enough is in your arsenal.
Let me know if this needs clarification.
I'd add "Have a nice day", but you won't.
Joe

[jameshoward]

Is there any way spring compressor could be used here? I've used one to remove the front springs in the past.

JH

[JimVillers]

Gunter ..... The way that I install front springs is to remove the lower trunion bolt form the kingpin to the control arm.  Bolt the control arm in place, place the spring in its proper orientation and then use a floor jack to compress the spring.  When the control arm is high enough, you can reconnect the lower trunion.  Easy, I have done it many times.  You might need a C-clamp to compress the two sides of the control arm to get the trunion bolt threads aligned correctly.