News: - All about the Car!

Main Menu

'79 350SE - new owner - some issues!!

Started by Mark, 06 June 2009, 05:11 AM


Hey folks,

Bought my first w116 today (already have a w115 & w123). It's a beautiful car, not perfect, but exactly what I was looking for!

There are a couple of issues which I could do with some help on...

1. Steering
The steering is nuts, it's gone past vague. It feels like the trackrod ends don't even exist, it just wallows around the road. Could this be a steering box failure or track rod ends, or both? Do I need to replace the steering box or is there a way to tighten it?

2. Locks
At the moment, the only way to lock the car is activate the central locking inside the drivers side and then jump out. The only way to get into the car then is to unlock the passenger side, then open the drivers door from the inside. Any ideas on this???

3. Coil
The coil has a permanent feed coming from the battery. Without this it won't run. I, obviously, want to get rid of this unoriginal wire - any suggestions?

4. Electrics
The dash lights dont work, the tail lights don't work and the indicators don't work?! All fuses look fine, but they're old. First port of call to replace these guys?

All help appreciated, looks like a great forum! Pictures coming soon!


A couple of pics if you're interested..

Nov '79 350SE with 115k on the clock. Cruise & black leather. Quite a high spec car for Ireland!


Congratulations, it's a nice looking car. The only advice that I have is, I too had no dash lights and was told to turn the rheostat dial (on the instrument cluster, next to the reset button for the trip meter) back and forth all the way to each end. Apparently the internals can rust a bit and by doing this you can achieve a good conact. Anyway it work for me.
1987 Home market 560 SEL


Nice colour Mark. 8)

Regarding the steering; if at a standstill and engine off you can move the steering wheel lightly back and forth with up to a small amount of freeplay, the steering box will be ok.  If it holds corners ok but is harder to keep in a straight line especially when there's no camber in the road, it's probably worn upper control arm inner bushes.  Actually I'm putting my money on them as being the issue but it's not unreasonable to suspect that other bushes, track rod ends etc may be worn too.  Have a search for front end rebuilds or similar as there's been a couple lately.  Here's a pic of my shot upper control arm bush.  A complete new arm was the answer. 

BTW, I did replace steering box on this car as well but the old one had excessive freeplay.

1973 350SE, my first & fave


Looks like a nice car.

1. Steering
There is coupling between steering column and steering box accessible from engine compartment. Known to fail, first and easiest thing to check. The steering box is adjustable with a screw and locknut on top side of box. Anticlockwise reduces play but be careful, if the box is worn and adjusted tight in the straight ahead position it will probably bind off centre - very nasty on the road.

2. Locks
Can you turn the key in the drivers door?

If yes the link between inside button and lock may have fallen off.

3. Coil
Coil is normally fed through one or two ballast resistors, they burn out. Or it could be a stuffed ignition switch (or quite a few other things!).

4. Electrics
Wouldn't worry about the fuses looking old, remove them one at a time, check they are in one piece, give the ends a clean with steel wool and put then back.

Have a look at the online manual by following the "LIBRARY" link for more details.

Boogity, Boogity, Boogity, Amen!


Regarding the steering coupling Knuckel. Mine was worn on all my w116's and as soon as you replace them it does improve the steering out of site. You can see if they are worn as the rubber is usally missing, however sometimes hard to see when in the car. You can buy them from austohauz.

But as koan has said you may still have other issues like i did. I had to replace tie rod ends as well on one of my cars.
78 450 SEL Parting out
78 450 SEL Saving for parts
79 450 SEL 6.9  #5332
77 450 SEL 6.9 Euro # 1696
77 450 SEL 6.9 Euro #1577
78 450 SEL 6.9  # 4172
76 280 S     Manual Parting
80 280 SE  Possible Parts Car
74 350 SLC  Thinking converting to race

another sad 280s

without a good steering coupling to look at it's hard to tell. mine looked fine until i touched the shaft and gave it a wiggle, feeling more movement than i thought possible. definitely worth doing. $125 and a couple of hours work.


Thanks for all the replies guys - what a brilliant site! I'll hopefully be making this into a build thread. It won't be nearly as fancy as half the builds here but it will be functional!!

MB_Mike - tried your advice and no luck :( Think it's all part of a bigger problem though!!

Oscar - I will test as you've recommended. If required, i'll just replace every bush!

koan - where is the adjuster screw? As for the locks - I can't turn the key in the lock - key works fine in passenger & bootlid.
What you said about the ignition switch is interesting and I've started to think that all of the electrical problems are related to that. All that works electrically is the sunroof, 3 electric windows (slowly) and headlights. Does that sound likely?

Andreas & another sad 280s - I reckon I'll order one of those couplings so!


Quote from: Mark on 08 June 2009, 03:52 PM
where is the adjuster screw? As for the locks - I can't turn the key in the lock - key works fine in passenger & bootlid.

On the top side of the box, a hex socket screw with a locknut around it. See the LIBRARY for details and pictures.

What you said about the ignition switch is interesting and I've started to think that all of the electrical problems are related to that. All that works electrically is the sunroof, 3 electric windows (slowly) and headlights. Does that sound likely?

Can't say for sure, tail lights should work in off position of ignition switch so unlikely. You may have several unrelated electrical problems.

Boogity, Boogity, Boogity, Amen!


Hello guys,

I'm back! I've only just started work on the car after leaving it outside for the last 6 months due to other projects (namely my historic racing Mini and W115). I have now been able to free up some space in the workshop and as I speak a buddy of mine is cutting out the rust from the rear inner arch.

I have managed to fix alot of the problems which were mainly due to bad contacts in the fuse box. I still don't have a heater blower and 1 taillight is out, but apart from that things seem to be ok. Quite a relief!!

I cannot turn the key in the drivers lock which is quite frustrating. The boot lock was the same but I managed to free it off with perseverance. I'm worried about damaging the key however (it's my only copy)

This is my main query.
I can move the steering back and forth quite a bit (approx 50mm) without the wheels turning. Steering coupling looks good, as when I hold the steering box end of it, the steering wheel does not move. The steering box therefore has quite a bit of play in it - will the adjusting screw fix this? I assume I remove the lock nut and then use the hex to tighten and then re tighten the locknut while holding the hex in place?

Does anyone have a picture of a warn steering coupling and a good one?

I can see a few warn bushes also, where is the upper control arm bush that was mentioned? Track rods seem ok.