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1982 380sl 'Vagueness' in steering

8K views 11 replies 10 participants last post by  bobfoley1276 
#1 ·
I have no record that the steering coupling was ever changed (admidst lots of maint records). My steering is what I would best describe as vague.. a bit, but not a lot, loose. The wheel has about +/- 1-2" (one to two inches, plus and minus)of slop at rest and you can feel the looseness when driving. Sort of always need to keep going back to left or right for a good road feel. Kind of always chasing the feel, if that makes sense.

Anyway, since I read lots of reports of worn, disintegrated bushings/couplers I pulled off the cover by the pedals and it seems the coupler is not really badly worn. I saw a Utube video of lots of slop and its nothing like that. There are bits of the rubber bushing crumbling but the play seems to be more into the box rather than the bushing/coupler itself. ( It could be replaced because you can feel some movement across the coupler when the other more pronounced play is 'taken-up') What is normal from the shaft into the box at the firewall?

So now a question? I read there is some steering adjustment someplace on the steering box? Do my symptoms sound like that might fix the issue? Where is the adjustment located? What's the best way to try to change the adjustment?

If that's not it... does the steering box need to be replaced/rebuilt? Seems like that would be the time to do the coupling.

A comment on rear sway bar links: Mine gave up the ghost a week ago and over the past week I installed new links. Huge difference from even when they weren't clanging and banging.


Thanks for the input.
 
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#2 ·
PetesMGA showed me on my 280slc (much more room around steering box) that there is a (i think) lock nut to loosen and then tighten (I think) an Allen bolt. Put your knee on the wheel as you turn the steering wheel with your hand and adjust the bolt until the play is minimal. Do not overtighten because wheel will not return to straight if you do. Tighten lock nut.

I have never done this, but I think my 1973 really needed it. I'm not at that point with my other cars.

I hope the info I have provided is correct and/or helpful.



Sent from AutoGuide.com App
 
#4 ·
I am guessing your steering coupler is the issue. Have someone sit and turn the wheel gently back and forth while you examine the coupler from above, under the engine compartment, tosee if there is slop from worn bushings in the joint. I had to replace the coupler on my 280slc off the bat, and that made a big difference. The part is about $50 from AutohausAZ. It can be done without removing the steering box, look for the detailed instructions by searching the forum. It is a job that is in the realm of DIY.
 
#5 ·
Lots of things can contribute to steering slop. Coupler is just one of them.

The steering box should be adjusted as a LAST resort after the whole front end has been confirmed serviceable and within specs.

Road sensitive tires can also contribute to the need to correct steering whilst driving.


My General Altimax tires are like that.
 
#6 ·
An inch either way for a total of two inches play in the wheel, is what I had. Everything was okay, after a few years I got used to having to make continuous corrections, until I hit the Potomac River crossing on I-81 at Harper's Ferry. It was under repair with traffic over on one side and the narrow lanes bracketed by concrete barriers. It twisted and turned. At each turn I could see a place where a vehicle had lost it and climbed the wall. I had only inches on either side, seemingly, and could not travel in a straight line.

Sheer terror.

Within 30 days I had a new coupler and a rebuilt steering box installed.
 
#7 ·
The coupler isn't too bad. I got at it through the foot boards removing the cover on the steering shaft by your feet. Its a bit wonky but turning the wheel, the majority of the 'slop' is in the box, not the coupling.

I read some posts about the adjustment and it seems there are as many do-its as dont touch its.

Looking/checking everything in the front suspension-steering, other than the damper which I just replaced, nothing is loose

Looking quickly, I can't see any adjuster on the box. Do you need to remove the manifold heat shield?
 
#8 · (Edited)
Have adjusted my steering box 2 times in 28 years, usually noticed as difficulty in tracking straight on uneven surfaces. It is simple on some of the engines, loosen a nut, adjust an Allan bolt (CCW reduce slack), tighten nut and test for binding/friction.

On my 500, I could not get to the Allan bolt (manifold in the way), so I removed the box altogether and adjusted it on the bench. Took me about two days and a lot of swearing.

Her are the steps I noted:
1. Set the steering wheel to straight ahead position and mark Pitman arm position
2. Remove damper, drag link and left tie rod using G type separator, unscrew the nuts 3 mm and put pressure on the nuts, not the threads.
3. Remove exhaust and left downpipe
Use a 13 mm socket on long 3/8” extension for downpip
4. Remove LHS heat-shield
3x 8 mm screws
5. Disconnect grounding strap below steering box
13 mm bolt
6. Loosen/remove steering column joint closest to footwell, it may be necessary to slightly turn the pitman arm to get access. Use 6 mm Allan key that can be used at slight an angle (rounded end). It may be tempting to undo the bolts closes to the box, but this end is splined, difficult to align and very difficult to re-mount.
The steering column end is square and easy to align and remount.
7. Drain steering box oil by undoing the 12 mm screw at the bottom of the steering box
8. Remove oil connections
17 and 22 mm nuts
9. Remove the three bolts attaching the box to the wheelwell wall (inside wheelarch)
3x 15 mm bolts. The steering box is quite heavy and need to be supported before removing the last bolt. Note the longest screw is towards front of car.
Lift box out from the underside of the car.
10. Loosen the 19 mm locking nut on top of box
11. To increase the steering torque, adjust the 6 mm Allan screw ¼ turn counter-clockwise. The torque straight ahead should be roughly 90 Ncm and 60 Ncm at the edges. Adjust at the edges as the center (straight ahead) torque depends on wear.
This can be measured using a fixed weight at an arm connected to the input spline.
An old steering coupler and a fine brush shaft was used with a 25 mm spanner (400 g) positioned 15 cm from the input axle. See photo.
Make sure the box is not binding at any steering angle.
Tighten 19 mm locking nut whilst holding the Allan screw in a fixed position.
12. Mount in reverse order, refill the steering box with automatic transmission fluid (ATF). Align the Pitman arm before mounting, check that the indicator canceling is working before attaching the drag link, damper and tie-rods.
Prepare to spend a lot of time to attach the steering coupler Allan bolt, space is very tight. Make double sure the bolt is tight.
Crank the engine for a short while and refill power steering with ATF immediately, it is very noisy without oil.
 

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#11 ·
Steering play was always a 107 problem.
Even Mercedes admitted that after a few thousand kilometers every new car will have a steering play of about 2 fingers left/right. So that's what i would call normal, everything else or anything giving you trouble driving should be corrected. (Keep in mind a new original "old" steering box will probably show the same 2 fingers symptoms after some time!)
For small corrections it is worth adjusting the screw.
Judy
 
#12 ·
Steering solved

I got to loosening the nut on the box this evening. All in all, not too bad once I found it(just as another member noted) pull last plug wire, remove heat shield, soak with oil, crowsfoot, wobble, breaker bar: loose

It took about 1 to 1 1/4 turns to get rid of loseness, and I might be a bit tight but what a difference. Just like real steering for a 30 yr old car. I might change the coupler for last bit of play but a huge difference.
 
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