bruce7

DIY - Horn Retaining Ring R&R

This DIY will explain how to remove and replace the horn retaining ring for a 97 993 with the standard 4-spoke steering wheel. This fixes the problem where the horn sounds when braking. The problem began appearing on my car this spring when air temperatures began to climb above 80 degrees. There are rubber suspension grommets in the ring which become soft and too elastic and permit the horn contact to be made when braking.

Pictures for this DIY can be found here:
https://picasaweb.google.com/bruce.c...Nq6n6Xn8p2kEg#

Parts & Materials Needed

993-347-088-01 horn retaining ring $75 at Sunset Porsche
Dielectric grease (optional - for battery terminals)
Security code for radio


Tools Needed

T30 Torx Socket Driver (I used Snap-on #FTXL30E. It is 4-1/2 inches long with a 3/8 drive.)
or
T30 Screwdriver, 8 inches long (any longer and it won't fit between the dash and the steering wheel.)
13mm wrench and socket (for battery terminals)
19mm wrench (for the 4 bolts holding the retaining ring in place.)
Battery cleaning brush
Battery terminal puller (optional - useful if terminals are corroded)



Procedure to Remove and Replace Horn Retaining Ring

Note mileage

Removal

Disconnect battery
Wait 15 minutes to let air bag capacitors drain

Remove the 2 T30 torx bolts in the steering wheel hub (they will remain inside the hub)

Pull the air bag pad away from the steering wheel

Disconnect the 3 wiring connectors (black, red, and yellow) and set air bag aside.
(The yellow connector can be simply levered up with a screwdriver from the back
of the air bag unit.)

Remove the four 19mm bolts holding the retaining ring to the steering wheel

Remove the horn retaining ring and torx bolts

Installation

Place the 2 torx bolts into position in the plastic hub

Place the retaining ring into position over the torx bolts, insert the 4 19mm bolts and tighten.

Reconnect the wiring connectors and refit the air bag

Tighten the torx bolts

Connect the battery
Finish Up

Check horn operation
Check air bag light comes on and goes off
Reset the clock
Reset the radio security code
Update the log

P-daddy

Very nice DIY Bruce! Thank you for sharing.

mbpa

I recently performed this repair, but just a word of caution. The part is suppose to fit 96- models, but it turns out some 96 cars actually still have the old deeper frames which, as far as I know, aren't available anymore. This is what happened with my '96 targa when I got into it, so I ended up removing the rubber parts from the shallow frame and putting it in my original frame. Not the end of the world, but a good 2 hours of extra work.

Alternatively, the rubber pieces can be bought separately here:

https://www.allzim.com/acatalog/Horn...ings__993.html

Michael

bruce7

Hi Michael,

Great tip! Thanks for that link. Any details on how you pop out the old bushings
and press in the new ones?

-bruce

slangford

Awesome guys! I just started investigating this issue with my '96 this past weekend, and got as far as trying to disconnect the airbag. In my case, the connector is red instead of yellow, but looks to be identical. I just am not sure how to remove it - I did not want to screw around with a $2000.00 air bag, so stopped. Any comments?

Also, these pictures look just like my horn ring, but I have read earlier threads re a potential mismatch of old versus new replacement parts. Can we confirm that new ring will fit a '96?

Much appreciated ...

Steve.

bruce7

Hi Steve,

If it looks identical to the yellow connector, then you should be able to pry it
up with a screwdriver very easily and disconnect it.

-bruce

Chris V

^^^^...what he said

I replaced my 4 spoke steering wheel this weekend with a 3 spoke. All the DIY photos I saw had a red air bag connector and mine was yellow, but other than the color it was the same type of connector. I could not pull it out with my fingers but a gentle pry with a flat screw driver and it popped right out.

slangford

Thank you again guys - gentle screw-driver pry it is, this evening. If you hear back from me tomorrow it meant things did not go so well ... :-(

Now I just need to ensure I can get hold of the right replacement ring - not lovin' that idea of prying the new grommets out of a new one and refitting them to my old ring ...

bruce7

Steve,

Here are the two pages from the PET that cover the horn retaining ring.
The second page says that the part number for 96 and 96- are the same.
I would call Sunset Porsche and try to clarify.

Unrelated, I have run into a situation with the bolts that fasten the heat exchanger
to the catalytic converter were incorrectly specified in the PET.
For -96 they specified 37mm bolts and for 97- they specified 25mm bolts,
but my 97 used 37mm bolts. It is what I would call a "boundary condition"
where they were in the process of changing the production and the
specification could go either way.

-bruce

nine9six

Steve,
Make darn sure to disconnect the neg batt terminal and allow the airbag capicitors to fully discharge. You dont want to know why I am emphasizing this step...
...and no, its not because the airbag will discharge on you, but you will need to find someone with a Porsche PST-2 or Hammer diagnostic tool to turn off your airbag light if you forget this step.

God bless mgianzero, and his resourseful self...

slangford

Thanks again guys. I appreciate the PDFs, Bruce, and the point about 'edge cases'. And yes, I have had the battery disconnected for a few days now. While I confess to being more worried about an exploding airbag than incessant warning lights, both make sense and I am avoiding either I hope ...

Steve.

ilopper

Am I the only weakling here? I'm using a 7 inch T30 screwdriver, and I can't get either of the two to budge at all. I tried using a wrench on the shaft of the screwdriver for leverage but being plastic it just slipped off.

Anyone feel like they used red Loctite to put these things in?

PRSWILL

Bruce, Thanks for the great walk through- I just became the proud owners of a 1996 C4S with this issue and ordered the part for 92 bucks from Pelican- I am going to perform this repair Thursday. Your pictures were also very helpful!

Thanks!

PRSWILL

Ok - I replace the Airbag frame tonight- was very easy thanks to Bruce's writeup- but the horn's still not activating. Prior to replacing the frame i had put the fuse back in it's spot and the horn went off like crazy. Now, After the replacement and fuse in place, no horn sounding- but I am hearing a click coming from what I believe is the relay- could this be an issue? if so, why would the horn work BEFORE I replaces the frame - albeit all of the time- versus not at all now.

HELP!

PRSWILL

As an update- the horn now works perfectly. I had the fuse in the wrong spot- duh! switched it around and all is right in the world! Again, thanks for the great walk-through. I completed the changeout of the air-bag frame in under 30 minutes with your guidance.