I'm replacing the rack on my 91 240 but am no longer confident the steering wheel is in the centered straight-ahead position. Its an airbag car so I want to be sure. Is there a way I can check that its centered without the rack in the car?

 

is the steering wheel level?

 

I can level it to where I think its centered but have no way of knowing if I'm off a rotation either way.

 

thats a pain if the airbag has a 'clock spring' connection (not sure if these do or dont)

 

Much experience with this.... I blew up my airbag, so I know how not to do it, and how to do it.

You DO have a clock spring.


Theoretically, you may be able to CAREFULLY adjust it with the wheel on. I did not do that, and always, 1) removed the airbag, 2) removed the steering wheel then 3) centered the clock spring and put the pin in place to hold it, 4) finished rack work, 5) replaced steering wheel, 6) remove clock spring locking pin and 7) re-install airbag. It's a bit complex but not hard.

First lets talk about how to theoretically adjust it without removing the steering wheel:

Your clock spring has 6 turns from stop to stop--and in my experience it is more like 5 3/4 of a turn--the point is it is not as exact as you might like. But if you go beyond that, you will destroy it. So if you Carefully turn the wheel until you get some resistance in one direction, then turn it back 3 times, and you will be fine. the thing is that the clock spring is connected to the wheel by two relatively scrony plastic arms. When you turn it until it stops, note that it is pushing against these very small plastic arms. you can easily snap them off--in which case you will have a broken clock spring, and the wheel will not stop.

The alternative method is to remove the airbag. (Incidently, the greenbooks say if you do any work on the steering rack system at all on an SRS equpt car, you should remove the airbag and lock the clock spring. I did not follow this procedure, and blew up my airbag.) Here is how to do it:

First, Make sure your battery is disconnected.

Second, Remove your airbag. There are 2 t-25 torx head screws in the back of the steering wheel. Loosen those. They are usually trapped in the back, so they will not come out, just make it until they are loose. The airbag will start to come out, but there is a cord attached to it. very carefully, making sure that there is no static electricity on you, remove this cord. I generally do so from outside the car, through the window. (I had one go off on me once, and it left a nice mark on my arm for several days.)

Once, the airbag is out of the way, you can see what is going on... let me see, I've got pictures here somewhere... maybe this will help. (note, this is after I broke the clock spring, so the wire that comes out of it is missing.)



Thrid, you will see a large 27mm bolt that holds on the wheel. Remove that. you will need a deep socket for this.

You should be able to see the clock spring now. Wind it until it stops in one direction, then back 3 full turns, or thereabouts (I think mine was like 2 2/3 turns or so), until it is centered properly. In the bottom of your steering wheel, there is an odd philips screw that seems to do nothing. that is correct--pull it out, and screw it into the clock spring at the bottom. (you will see where it goes--make sure you screw into the little retaining hole.)

Then reverse the procedure, put on steering wheel, remove philips screw from clock spring, put it back in the steering wheel, carefully re-attach airbag cord, then screw in airbag.

When I did my rack work, I ended up doing that a few times, because it took me a few times to get the steering wheel centered just right with my wheel direction.

Anyway, hopefully this helps a bit.

 

Great write-up. Easy to follow and describes exactly what I needed to know. Unfortunately (or maybe fortunately) when I removed the airbag I discovered the plastic stops already broken and the orange airbag wire insulation was damaged. I've since relegated the airbag to the corner of the garage and will probably just put in an aftermarket wheel. The rubber is split on the bag exposing the innards anyway.