Power Steering Gear Box leak

[zoegrlh]

I have acquired a leak at the Power Steering Gear Box set screw.  This is on top of gear box directly over the idler arm.  There are two hex nuts (one a cap nut) and a round nut with two holes in it for a special wench.  There is a seal ring in the round nut that needs to be replaced.  I have took the cap nut off and have tried to unscrew the locking nut but it is locked so tight to the round nut that when I turn the wench, both nuts turn along with the set screw.  Has anyone had a similar problem when replacing the o ring seal.  Do you need to clamp the set screw (there are two flat sides to the top of screw) to unlock the lock nut, or clamp the round nut to unlock the lock nut?  Do not want to damage the set screw.  HELP, need to stop leak.
Thanks

Robert Hyatt
Williamsburg, VA.

1970 280SL, Red on Silver,4-speed, Euro spec; 1999 C230 Kompresser Sport, Black on Black; 1990 Miata, Black on Red, 5 Speed

[nico]

I'm sorry to tell you that while unscrewing the nut under the capnut, you also disturb the setting of the pre-load on the main axle.
Your steering has to be overhauled, while all the other sealings will be just as bad [aged] as the one you are trying to replace.
NOT a job you can do yourself.
[I do this job very regularly, and have about a dozen special tools for doing this job].
Also; when taken apart the wrong way, you will damage the parts inside.
Good luck, and use your savings to have it repaired!
Nico

[jeffc280sl]

Nico makes some good points.  If you do remove the set screw and round nut make sure to remember the number of threads showing above the round nut.  That way you can return the round nut to the original location relative to the spring tension on the bolt. The round nut is also threaded.  The best way to remove the second nut make a tool that fits the two holes in the round nut and hold the round nut or disk in place while using a wrench on the smaller nut.  Once this lock nut is removed then you can hold the bolt by the flat sides and unscrew the round nut.

Read some of my earlier posts on the subject.  You should also find some pics.  If you need more info let me know.

Jeff C.
1970 280SL 4-speed

[zoegrlh]

Nico and Jeff thanks for the words of wisdom,  I think I will let my MB garage do it.  Don't want to screw-up my steering.  However Nico, If I don't break the locking nut loose from the round nut and the set bolt/screw turns with the other two nuts and threads stay at same adjustment, then I assume I have not changed the setting as of yet.  Only if I loosing the locking and round nut will the setting change?
What do you think?
Thanks,
Bob

Robert Hyatt
Williamsburg, VA.

1970 280SL, Red on Silver,4-speed, Euro spec; 1999 C230 Kompresser Sport, Black on Black; 1990 Miata, Black on Red, 5 Speed

[jeffc280sl]

The round nut establishes tension on the spring adjustment for steering play.  If it has not changed in relationship to the bolt you have not changed the setting.

Jeff C.
1970 280SL 4-speed

[PnHi]

zoegrlh
I had the same problem and eventually had to use a 1/16" drill bit on both sides of the nut to break it free.  Jeff C. was a hugh help via e-mail.  Before drilling the nut and eventually seperating it from the bolt, I counted the number of threads to the top of the bolt. Replacing the seal, new nut and the cap nut took all of 10 min.

Good Luck
Mike C.
"68" 250SL

[jeffc280sl]

Hey Mike,

I'm glad things worked out for you.

Jeff C.
1970 280SL 4-speed

[rwmastel]

Robert,

There's a lot of people who've posted about power steering box leaks.

http://index.php?topic=1558,seal
http://index.php?topic=6943,seal
http://index.php?topic=6104,seal
http://index.php?topic=1761,seal
http://index.php?topic=5300,seal
http://index.php?topic=2051,seal

The Manual has some info on it:
http://www.sl113.org/wiki/pmwiki.php?n=Steering.PowerSteeringBox

Rodd
1966 230SL: arabian gray, natural leather, euro, auto, both tops
2006 C230: alabaster white, ash interior.  Without: automatic transmission, sunroof, heated seats, full leather interior, full power memory seats, CD changer, Logic 7, Command, rain-sensing windshield wipers, rear window sun shade, headlight washers, electrically adjusted steering wheel, ....