107 steering coupling

[107owner]

Hi. I'm new to this site and have learned alot from the experiences of others. Thanks for sharing your knowledge. My steering was loose so I replaced A drag link on my 1982 380sl. It was worn, but after I finished the steering was still loose. So had my son move the steering wheel while i was underneath(the car was jacked and blocked up 3 ways-still kind of scary)and I found my real problem was the steering coupling is very worn. My CD manual doesn't tell me how to replace this. It looks like you have to either remove the steering gearbox or the steering shaft to replace the coupling. Any advice would be helpful. BTW, I ordered the part on-line at www.*************** for $57.00 +free shipping for orders over $50.00. The dealer wanted $148.00 plus the gold fillings in my teeth. It pays to shop around.

[RickM]

Yup that's the order to R and R....damper, coupling then adjust or replace the gear box.

I'm interested to see how you do with the coupler. This is likely my nest project.

[Drake]

Yes it can be done ... but not for the faint of heart.
Just did my '81 380SL
First if it is a job you never want to do again ... this is one! pay the price for merc parts not after market!
Unbolt gearbox clamp ..coupling will slide up column a bit ... unbolt firewall boot under dash and slide up ..this will get you to top clamp bolt ...unbolt 3 15 mm bolts to gearbox ...this will let gearbox move a couple of in... coupling will now come off
when you put it back together have helper on the steering wheel for line up
spray paint gap in lower clamp to mark splines....top clamp can only be out 180 degrees
...but if you miss it turn signals won't auto turn off
good luck and have fun!h

[107owner]

Too late to buy part from dealer.
My part from Arizona should arrive within a day but i will look at it and see if it looks beefy enough.
My understanding is that are no aftermarket couplings available, only OEM. We'll see.
I took a better look at the coupling from underneath the car and it looks like I can loosen the coupling bolts (2) which are set (Allen) screws.
Then I should be able remove gearbox bolts (3) from inside fender well and move gearbox enough to remove coupling.
The Pitman arm may have to be removed also.
I will evaluate that once I start.
The tip about spray painting the gap is a good one.
When I have completed the job I will chronicle my experiences on the forum.
Now I have to actually do the work!!
Thanks for the help.
Kraig

[Drake]

You won't have to remove the pitman arm (after this many years that can be an adventure to its own) The couplling will slide up the column a couple of in ... it will be stiff (colapsable) tap with punch.
my new coupling came with star instead of allen.
finding metric star to fit took as long as the job.

[RickM]

Kraig, If you haven't done this job yet please take some pics. Thanks.

[RickM]

Anything to report?

[Captain Scott]

Originally Posted by 107owner

Too late to buy part from dealer. My part from Arizona should arrive within a day but i will look at it and see if it looks beefy enough. My understanding is that are no aftermarket couplings available, only OEM. We'll see. I took a better look at the coupling from underneath the car and it looks like I can loosen the coupling bolts (2) which are set (allen) screws. Then I should be able remove gearbox bolts (3) from inside fender well and move gearbox enough to remove coupling. The Pitman arm may have to be removed also. I will evauate that once I start. The tip about spray painting the gap is a good one. When I have completed the job I will chronicle my experiences on the forum. Now I have to actually do the work!! Thanks for the help. Kraig

Hey Kraig,
I am about to move on replacing mine. How did it go??
Scott
'74 450SL with 221K

[Captain Scott]

I am tight once again!

The main hiccup I found was in having to access the coupling bolts from the driver side inside the car, upside-down of course.
I had to take the boot off the firewall, slide it toward the steering wheel and then cut down an Allen wrench so it would fit thru the pass-thru.
Then it was simple.
Of course you need to mark BOTH shafts before you pull the old coupling.
Spray paint might work, but since you will want to spread the coupling to ease removal, you can just drive a slim chisel in to spread it and also mark the shafts.

Scott

[KATSCAN]

OK, I'm starting my coupler work now.
I can't seem to slide the firewall boot up the shaft.
removed column shaft screw also.
The boot won't move.
Everything tries to move with it as one piece.
What's the deal?

[Captain Scott]

Once the 4 screws that hold it to the firewall were out and the strap collar nut was loose, I had to pry a bit with a screwdriver between the metal "boot" and the firewall to get it moving and eventually, I grabbed it and twisted it up toward the steering wheel.
There was also a rubber gasket that was almost fused to the firewall.
Be careful, the edges of the metal boot are sharp.
Maybe a shot of nutzoff or WD-40 will get her moving.
Good luck.
You'll love the results!

[KATSCAN]

Well, I did get that off/loose from the firewall, it just needed to be twisted/rotated back and forth, and apparently, was doing that when you wrote.
I'm kinda po'd now cause my steering attachment of the coupler/ not the gear was near the end of the round tube....I couldn't get it to slide up.

Well, in fact I was following the thread and it said to loosen gear box side and it will slide two inches.

I'm not sure it can unless you loosen the steering side too, duh.
Well, since it didn't slide, I loosened the steering side. And proceeded to the gear box bolts.

Not even thinking to try to slide again.

Well, the gear box slides good but the coupling came off the steering wheel Hollow rod.

Now, You can't put it back around that rod so the steering column now must come off.

Not enough play now to get full slide and off).

Your's on the other hand (coupler) was slid up further to begin with because you couldn't get to the 2 nd Allen screw on the coupler.

I could get to both of mine from the engine compartment.

So anyone else that tackles this make sure you double check about the slide. Especially if you can unscrew your coupler (both nuts) from the engine compartment.

Just a "little" more work

[KATSCAN]

Did not have to take steering column out, etc.

I have a tendency to do almost exactly as it's written.

I usually do not take bolts all the way out in order to keep them with the part.

On this job make sure you take the coupling bolt all the way out from the steering half.

It will save you a lot of cursing, gojo, and at least one trip from confession.

[KATSCAN]

I'm having a ***** of a time putting the coupler on. I put the steering side on and can't get the box to get in all the way. Do I hammer or what?

[ctaylor738]

This is not a hard repair.

You remove the steering wheel and the combo switch, then the three screws in the steering hub that hold the steering shaft in.

You undo the coupling screws (a 1/4" hex bit ratchet and sockets really help) and pull the steering shaft up a couple of inches.

Install the new coupling, and reassemble in reverse order.

The only trick is to mark both ends of the steering shaft so you get everything to line up the way it was.

Otherwise you will have an off-center steering wheel and the turn signals will not cancel correctly.

Try a search - I did a detailed post on this when I replaced my steering box a year or two ago.

And it is on the CD.

I am not making this up.