resealing steering box?
 

Is replacing the seals in a steering box, W140 in this case, a straightforward task or does it require special tools and precision measurements? The bottom of the SD steering box is a little wet. Wondering if I should try to reseal it or let it get worse then replace it. Steering and tracking feel fine.

To put it in perspective, I can replace a head gasket but I don't have the skill or knowledge to work on a differential.

Thanks,
Sixto
93 300SD

Special tools, lots of 'em, if you want to do it right. The dealership I was at recommended reman boxes, no rebuildingon the premises. WAY expensive tools. Maybe you can search for a place that will rebuild yours, MB charges an arm and a leg for remans, usually only slightly less than a new box, but I think that's a reflection on how hard it is to do these right.
Gilly

What's another leak? :)

Sixto
93 300SD

cdplayer
 

I had a leaky steering box too. Found all the how-to info in this forum. Whunter had excellant info and step by step. Changed it myself. I found a shop on Ebay and purchased a rebuilt with a three year warrenty from CarSteering.com. Free shipping too. And for $12.00 more I got a UPS return label to send the core back.
These people are great. And the steering box comes already centered. Makes the car respond much better.
I also recommend replacing the steering coupling as good measure. My car had 231,000 miles on the clock and the coupling had a couple of good cracks in it. Look in the DIY section of this forum to see pics of a bad coupling. Good luck.:D

resealing steering box
 

i agree with post above but for diff reason.during the 80's i rebuilt many boxes but started to find out that if some of the parts were worn to the point that new seals still allowed leaks after all that work.it became much more cost effective to use the rebuild skills of a cal. company and switch out boxes.for a diy job you have your work cut out anyway just keeping everything centered.[only have to be one tooth off to cause problems with turn signal cancelling].

Is this a common repair? (W126?)
 

Is it an O ring or something that goes bad on them?

I think mine's been done at least 3 times, since the car was new, and the car has 118k on it right now? Is this a common repair in these cars?

steering box
 

yes common repair.usually because neither fluid or filter gets changed until a problem arises and then the fluid is thick and dark.

I agree with Gilly. The failure rate is very high when these units are re-sealed. Even the after-market warranty companies I deal with won't pay us to attempt it. They'd rather buy a re-built and just have us install it. In my opinion, this saves EVERYONE a bunch of headaches.

And yeah that's a point I should have made too, if you don't have all the tools to do the job correctly, they leak right away too. We tried doing it like someone at home would, without the tools, and leaked worse than before you touched it. There's just NO room for errors on these steering gear boxes, very fine tolerances, and everything has to be set up properly, even if you just need to replace a seal, opens up a real can of worms. If you can find someone who can rebuild it cheaper, as long as they guarantee the work, I'd go for it, especially if another member can give them a good reference.
Gilly