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  #1  
Old 12-31-2008, 06:35 PM
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Question w126 Steering Gear Adjustment Question

Hi All, Happy New Year!


I have a question about my steering box, and I'm hoping that someone who has been through this before can offer some advice.

Okay, so I adjusted my steering gear in the car, but I didn't do the fancy torque meter method, I just backed off the adjuster, test drove, repeat etc...

The problem I am trying to cure is excessive play when driving in a straight line. I've been having issues with wind and road ruts pushing the car around. I should start by pointing out that I've replaced the ball joints that my mechanic decided were worn, I've put new shocks on the front, replaced the steering damper, and the idler arm bushing. I also put two new Michelin MXV4 on the front.

Ultimately, I wound up backing off the adjuster almost three complete turns. As I did so, it was only as I got to the third turn that I felt any resistance at all in backing the adjuster off. So, I tightened the lock nut and test drove it. I noticed a significant improvement, though it's still not as snug as I feel it should be. It also seems that the slop in the gear is slightly off center. By that I mean that I have little or no play between dead straight ahead and turning left. The car responds instantly when I move the wheel left at all. However, there is excessive slop between dead straight ahead and right turn. There are several degrees of slop before the car responds to the wheel being turned to the right. The result is wandering all over the place under certain conditions.

I would like to try adjusting the gear a bit more, but I am beginning to wonder if either the gear is too worn to adjust, or there is some other component that is responsible for this type of slop. As far as I can guess, it is in the gear.

Has anyone had success curing this condition with adjustment? Is three full turns way too much for a good steering gear? The car has about 125K miles on it, and the paint on the gear adjustment lock nut seems to indicate that I was the first person to attempt adjustment.

Also, does the off-center nature of the slop indicate anything? I am thinking that if adjustment does tighten it up, then my wheel will wind up cocked to the right when driving straight. Is this correct?


Any help very much appreciated.


Thanks!


-tp

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  #2  
Old 12-31-2008, 09:30 PM
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Join Date: Jan 2003
Location: Dallas
Posts: 792
Panzer, It's been more than 5 years since I took my steering box apart and resealed and adjusted it, so memory is kinda stale. However, I can relate a few things.
My '91 300SE runs straight and true, until there is any wind, then it wanders like a drunken sailor. This started about 10 years ago as I remember, and I tried for over 5 years to find the problem and fix it. EVERY part of the front and rear suspension has been replaced, with no help. I ran out of things to try about five years ago. Biggest help was the steering damper.
I have begun to wonder if it is related to the 16 inch wheels I installed about 10 years ago. They have the correct offset, tire diameter, etc; but who knows?

3 turns on the tension adjuster seems like a heck of a lot. When I first adjusted mine at about 80K, I definitely noticed it tightening up before 1/2 turn out. The friction surface is an organic washer, maybe it is shot in yours.
As you know, with the engine off, about 2 inches of play at center is normal; it goes away when the pump is running. Checking friction can be done pretty well by just jacking the wheels up; you can feel the difference the adjuster screw is making. Better, of course, is to pulll the pitman arm.
As you probably know, the friction is supposed to be higher near center (approx 120 NCM), then decrease as the wheel is turned L or R.

Don't know why the centering is off; may be tied to the 3-turn issue.
There is a bolt under the box near the pitman shaft that can be removed, and a pin can be pushed up into the box to locate and hold the center position (there is an indention in the gear that the pin will slip into when the gear is dead center). You might try that; it's possible your steering wheel is not set at dead center on the steering shaft?

When my box started to leak, I took the opportunity to buy a repair kit and take it apart. it was really pretty easy; of course I didn't take the whole thing apart. But while it was on the bench, I did some math with a rod and a hammer head, and did the friction adjustment per the book. result; leak stopped, friction correct, still wanders in the wind.

Good luck. If you find the wandering problemit, let me know; I'll be your friend for life.

DG
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  #3  
Old 12-31-2008, 09:51 PM
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Thanks for the details and your history with this issue.

I'm sad to hear that you were unable to cure your wind wander......

Mine has gotten better since I adjusted the box, it seems that at straight ahead the car cannot drift left, but can drift right. I think that is tied to the uneven nature of my play. In other words, I think one side of the gear is snug and the other has a slight gap, thus giving you responsiveness in one direction and slop in the other.

And, if you have to steer just a little to the right into the slop zone, then that car can wander either direction, but not any further left than you have turned the wheel right. In other words, it can wander from the slop zone to the left but it stops drifting left when it hits the end of the slop. Does that make sense?

Just now, I noticed that if I swing the wheel back and forth with the vehicle off but the wheel unlocked, I hear clunks as the wheel hits the end of the slop zone. Something's got a gap in it. Something is worn. The flex joint looks ok, but I'm really gonna dig into this this weekend and find the problem. It really is taking all the fun out of driving the car.....


Thanks again for your help.


Happy New Year.....


-tp
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  #4  
Old 01-01-2009, 11:16 AM
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Join Date: Jan 2003
Location: Dallas
Posts: 792
I just walked out and tested mine; yanked lightly left and right (with engine off) and it moves about 1 inch in each direction, and clicks both ways.
I actually hear about 3 quick clicks going left; it sounds exactly like 3 of the balls in the steering box clicking together. I think that's what it is, as there are 24 balls in there I think. With engine running, all the play goes away.
Mine has had this engine-off play since new.

Spent a lot of time with her yesterday - installed a water pump. I had forgotten what a job that is.

DG
DG
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  #5  
Old 01-05-2009, 11:10 AM
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Location: Dallas
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Panzer, I decided to just double-check my gearbox adjustment.
Several years ago I resealed the box, and I rigged a little lever/weight setup just like the book shows, to set the friction load on the workbench.
It all went well, and the steering wheel felt good, but the car still wandered.

But, yesterday, I loosened the jam nut, and was able to turn the adjuster screw 1/4 turn CCW before I felt any resistance at all.
I tightened it down right at that point.
Lo and behold: the wandering seems to have diminished noticeably. There was a pretty good wind yesterday, and we drove about 20 miles. Still moves around more than I think it should, but feels better.

DG
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  #6  
Old 01-05-2009, 04:16 PM
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Interesting, I am finding much the same thing....


Yesterday, I decided to try to adjust the gear once again, on top of the nearly 3 turns I had already backed off the adjuster. Gave it another half turn.

Definitely an improvement. My slop (engine running) went from almost 3 inches to now just under an inch. It STILL needs another half turn I think. The steering has become much more responsive, and I almost had to "get used" to it all over again.

Interestingly, as I had guessed, my wheel is now cocking to the right in the dead straight position. I think this is because I had so much slop in my gear that there was no real way for the alignment shop to center my wheel accurately.

I plan to give it yet another half turn today, and see how it goes. Definitely not too much friction yet, as the steering straightens itself out after a turn just fine. I'm just beginning to wonder how much more it will go before there is no more adjustment room left.

I am going to start keeping my eye out for a steering gear......


-tp
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  #7  
Old 01-06-2009, 10:12 AM
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Location: Dallas
Posts: 792
Panzer, as we discussed earlier, if your wheel cocks to one side while driving, it's very possible the steering box is not centered. This would probably affect the feell/play, as the unit is designed to increase approx 25% in resistance in the straight-ahead position. A quick check might be to measure the length of each tie rod, and compare. An alignment shop "should" lock the box using the centering screw hole near the pinion, but very few probably even know about it.
In lieu of finding a reasonably priced replacement, you could buy the seal kit, as I did, and go inside and check it out. Looking at mine, it appeard the major wear point would be the pinion teeth, and mine looked really good there.
Mine had a leak, along with my unsolved wandering issue, so that was my reason for diving in. I didn't go much further than pulling the pinion shaft out and replacing all the seals. But I was able to disassemble the adjustment screw and washers, and check them out; then do the friction adjustment on the bench. I believe though, that even though I oiled everything, the adjustment settled in and loosened up after running awhile.
But, this would give you a good chance to check out the adjuster washers, and shim them up as outlined in the manual.

DG
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  #8  
Old 01-07-2009, 05:51 PM
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Well, today I got the answer I was looking for, and I didn't like it.

Last night I decided to see if I could get the last bit of slop out, so I adjusted it a bit more. Well, it took some of it out, but the steering is now definitely too stiff.

As far as I can tell, there is something worn in the gear that adjusting will not fix. Could those washers you mentioned be to blame?

The symptoms now are a bit different. Even though the steering is now very stiff (I will loosen it soon), There is still a spot in the center where there is play, and no resistance at all. So, there's almost an inch of play with the engine running and driving straight. Now that the gear adjusted so stiff, you can really feel the difference between the slop zone, and when your steering input actually moves the wheels. It's NOT in the flex joint or in the steering column, I have carefully checked that out and it's perfectly snug.

Today was the perfect day for a test drive, very strong gusts of wind on my drive to work. Stronger gusts than we've had in a long while. The car did hold its place on the road better, but it seems that as long as the steering wheel is in the "slop zone", which is now much smaller, the car can wander around. When driving around gradual turns at speed, you can tell that the car doesn't want to wander while the wheel is turned past the slop zone.

I guess I need to start looking for another gear, or consider doing a re-seal and washer replace.

Does anyone know if these washers will help my issue, or is my steering gear just shot?


Thanks!


-tp
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  #9  
Old 01-07-2009, 08:42 PM
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Well, I adjusted it back to where I had it a day ago. It's much less stiff now, but still a bit on the stiff side (except for the middle slop zone). I may even loosen it up a bit more just to not cause undue wear on some other component. I think that something is worn, and that the tightening of the adjuster only attempts to mask the real issue.

I guess I better start planning on pulling it apart.

I just wish I knew for sure if my issue was related to those washer shims (which I still can't find any info on) or if I need to start saving $$ for a steering gear.


Humph....


-tp

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