Steering Gearbox Rebuild - PeachParts Mercedes-Benz Forum

75Sv1 · #1 10-23-2007, 11:48 AM

I found this link:
http://www.davidpetryk.net/Mercedes/Steering.htm
I rebuilt my PS pump and had the kit for the gear box. I removed the gearbox on Saturday. Then I rebuilt or resealed the pump on Sunday. I ended up with extra parts as the article states. I did have a few problems and haven't adjusted the tensions in the gearbox correctly yet. One of the valve bodies in the article wasn't on my gearbox.
The problem I had was self inflicted. The worm gear spun undone while I had the assembly in the vice to take off the large nut. The ballbearings went everywhere. I found 24 of them. I had some instructions from other sources. They said to load the BB from both sides. Some of the BB slipped to the other side of the worm gear. This caused the gear box to jam up from time to time. I dissassembled the unit again and feed them from one side. Also, on the top loop (metal 'U'), I put grease on one side to hold the BBs in place. I saw this on another rebuild.
I have the initail tension a bit under 43cm-N. It seam stiff. This is with a clicker type torque meter. I haven't set the center torque yet. I had it at 135 cm-N or higher. I hope to borrow a dial gage torque meter. I used the coupling and used a 1/2 square socket adapter. Turned the clamp screw all the way in.
I'll try and update when I get this properly adjusted.

Tom

Mister Byrnzoil · #2 10-23-2007, 12:40 PM

wow, thats a great writeup. Thats getting permanently saved. Thank you david petry whoever you are.

Sorry to hear about your issue.... did you decide to rebuild because of sloppy steering? excessive leaking? or both? neither?

my 84 has developed a leak @ the pitman arm seal... no doubt b/c of the the excessive loads on the box from the huge footprint of my 17in tires.

MattBelliveau · #3 10-23-2007, 01:11 PM

This will be a popular thread. What car is this on? It's about time someone found an pictoral on this topic!

75Sv1 · #4 10-23-2007, 01:18 PM

I only drove the car a handfull of times. I didn't notice any problems with the steering, nor any leaks. I took out the complete interior (except the headliner and rear seat, yet). Since I rebuilt the PS pump and I took off the Oil Filter housing, I wanted to torque the oil filter housing bolts. I guess I could have bought an allen extension with the ball end. I also cleaned the frame in that area. I don't think reassembling the worm gear was that much of a problem. It was finding the BBs, having to clean the garage to make sure I found them all and then assembling it correctly. Yes, I tought his article was very well written and excellent pictures. I didn't bother to take any. I did notice that the lower lube port on mine (pitman arm end) looked to be blocked ot gummed up. There was some discolorization on it. Many of the O-rings were flat when taken out. I have new hoses too. I plan to use synthetic PS fluid.
Tom

MattBelliveau · #5 10-23-2007, 01:28 PM

Quote:

Originally Posted by 75Sv1

I only drove the car a handfull of times. I didn't notice any problems with the steering, nor any leaks. I took out the complete interior (except the headliner and rear seat, yet). Since I rebuilt the PS pump and I took off the Oil Filter housing, I wanted to torque the oil filter housing bolts. I guess I could have bought an allen extension with the ball end. I also cleaned the frame in that area. I don't think reassembling the worm gear was that much of a problem. It was finding the BBs, having to clean the garage to make sure I found them all and then assembling it correctly. Yes, I tought his article was very well written and excellent pictures. I didn't bother to take any. I did notice that the lower lube port on mine (pitman arm end) looked to be blocked ot gummed up. There was some discolorization on it. Many of the O-rings were flat when taken out. I have new hoses too. I plan to use synthetic PS fluid.
Tom

Did you rebuild the gearbox just because of leaks, or slop, too? Did it seem to help the slop? Thanks.

75Sv1 · #6 10-23-2007, 02:32 PM

The article is for a w124 or w126 I think. Mine is an 81 240D with a manual transmission (W123). The rebuild procedure was nearly the same. There was an extra valve in the article, that was not on mine.
Mine was operating fine, with no apparent leaks or slop. I had the rebuild kit, and needed to take off the gearbox to properly torque the oil filter housing screws. I also had out the steering column and rebuilt the PS pump. I know I would want to rebuild it later. So, since everthing was off, I rebuilt it now. I haven't driven it yet. I need to adjust the gearbox. Also, install the interior, time the injector pump and afew other things.
Tom

rrgrassi · #7 10-23-2007, 02:49 PM

This needs to be in WIKI or the DIY section of the forum...

MattBelliveau · #8 10-23-2007, 03:52 PM

I'm really interested to see if anyone can step up and say that this procedure has effectively removed the slop from the system. I've got way more than is desirable, and would be MUCH more interested in spending ~$30 to get it out, than a whole new box. Thanks!

Stevo · #9 10-23-2007, 08:10 PM

Quote:

Originally Posted by MattBelliveau

I'm really interested to see if anyone can step up and say that this procedure has effectively removed the slop from the system. I've got way more than is desirable, and would be MUCH more interested in spending ~$30 to get it out, than a whole new box. Thanks!

You didn't try too adjust it? Not that hard, you just have to be careful not too 'overdue it'

Hatterasguy · #10 10-23-2007, 10:34 PM

I wonder if you can really adjust the slop out in that manner. The screw on the top doesn't really do much, it just adjusts the tension, it doesn't really affect play. He is diving into the guts an adjusting the position of the pinion gear and how it mesh's. Those are pretty heafty gears in theory they should last forever.

Maybe I'll get another kit and give this a try, if it doesn't work I'll cough up $600 for a rebuild.

I hate having slop in the gearbox, makes the car drive poorly.

It doesn't look any harder than rebuilding a 2 or 3 speed Harken or Lewmar winch.

75Sv1 · #11 10-24-2007, 07:15 AM

I tried again to adjust the unit last night. The basic tension was set at a bit under 43 cm-N with a click type torque wrench. I tried to set the middle to 107 cm-N or so. I couldn't get the middle of the gear set that way. The ends of travel would go up. I think the middle of the gear is worn. I adjusted the gear so it is about even through out its travel. Probably about 75 cm-N. I'll give this a try. Probably in a few years, I'll by a rebuilt unit or get a used unit to rebuild.
Tom

MattBelliveau · #12 10-24-2007, 09:05 AM

Quote:

Originally Posted by Stevo

You didn't try too adjust it? Not that hard, you just have to be careful not too 'overdue it'

Yeah...I might have...overdone it...

My adjustment is as far as it will go. I still have lots of play. Its drivable, I have no problem with it. If someone else drives it, though, I can definately see them putting in a full time job...cars ALL over the road with someone else behind the wheel. All the other steering components are less than a year old, so...

Stevo · #13 10-24-2007, 10:31 AM

Quote:

Originally Posted by MattBelliveau

Yeah...I might have...overdone it...

My adjustment is as far as it will go. I still have lots of play. Its drivable, I have no problem with it. If someone else drives it, though, I can definately see them putting in a full time job...cars ALL over the road with someone else behind the wheel. All the other steering components are less than a year old, so...

As long as there is no binding and the steering wheel returns when going around a corner, you wouldn't want too damage the steering box if its OK, because it sounds like the problem is in the suspension. You can usually help "sloppy" steering with the adjustment but you need too dig deeper.

Hatterasguy · #14 10-24-2007, 11:06 AM

Again the "adjustment" on the top of the box just increases the tension which makes the wheel a bit harder to turn. It will not remove slop, just make the slop feel tighter.

The slop is probably from a worn pinion gear, if you can adjust the angle of this you may be able to eleminate it. Thats what this article is talking about.

Graminal95 · #15 10-24-2007, 11:33 AM

Have a look at page 46.7-220/8, in the service manual, chassis and body series 123 volume 1 and you will see a cut away for the steering box.

It shows that the gear on the pitman shaft is tapered down at the top and that the working piston, the other gear that meshes with the pitman shaft is also tapered. What the adjustment screw on the top of the steering box does, is move the position of the pitman shaft on the vertical. By moving the pitman shaft up the slop/lash can be removed from the gear thus eliminating almost most of the excess play in the steering box. These boxes are old and well worn so total elimination of the play is high hope.

The previous owner of my 240 bought a rebuilt steering box for around 400 bucks. The box was rebuilt, but I don't think the worn gears (pitman shaft/working piston) was replaced. The play was massive when I got the car, realized the installer of the box did not adjust it and so screwed the top adjusting bolt out a bunch. Play was at a minimal but has started to get worse over time. I checked the PS filter/fluid and it seems the installer changed nether and it was full of grit and crap. Its flushed now but I think the damage was done.

Now if we could just find the 3rd version of the box (found on w201) that fits out cars, they have automatic play compensation.