Bilal928S4

Yesterday, I successfully removed the tow hook plug from my 90S4.

Bilal928S4

I wasn't that lucky when I tried to remove the plug from my 91 GT. It sheared the allen socket.

Bilal928S4

So my question is how can I put penetrant into the hole from the back of the opening?
TIA.

martinss

Maybe we could rate the condition of our cars on the THP (tow hook plug) scale? From 1-10 where 1 is best.

I had to drill out the plug from my relatively high mileage '88 that has seen Winter salt. After that I as ready for a fight on my Japanese '90 - the plug could almost have come out by hand!

So the '88 rates a THP of 8, whereas the '90 a THP of 1 or 2...

ALKada

That looks like a job for Kroil from Kanolabs.com .

poindex30

Martin,

How did you drill out the broken allen key in your '88? I just broke an allen key in my 1990 S4 and I've tried using a punch and carbite drill bit but nothing will penetrate the allen key. I'm just about ready to take the car to the dealer.

I've considered taking off the front bumper but I only feel comfortable getting under cars on ramps and this car is too low to ride up the ramps I have.

Thanks,

Mickey

Bilal928S4

The 90 S4 is my daily driver with 128K miles on it. The 91 GT is the garage queen with about 70K miles on it.
So I would have rated the 90 S4 as a 10 and the 91 GT as a 2-3.

martinss

My Allen key did not break fortunately, it just stripped the hole. Since the keys are hardened steel they are hard to drill out. However, you could drill around them using a metal hole saw blade without the centering bit. The plug is very soft and easy to drill. If you take this approach try to pick a hole saw size with an OD slightly smaller that the ID of the tow socket so that you do not damage the threads of the socket. A 1/2" should be OK, but measure first. You will have to pick out the residual plug pieces afterwards. Good luck.

Rob Edwards

The tow plug threaded hole is open at the back, which is the basic problem why the plug seizes in the hole, as all sorts of crap settles in there. But you ought to be able to get a straw from a can of Kroil up in there from behind, and soak it in.

Bilal928S4

Rob,
I tried looking for the rear opening but it looks to be covered unless the front bumper is removed.
Do you have a suggestion of how to get to the rear without disassembling anything?

poindex30

Thanks Martin, I'll give it a try. I think that might work.

NoVector

To seal up the rear of the hole, I bought two plugs from Roger. On one, I cut off the ring so it was just a straight shaft, coated it with antiseize and with a punch drove it 3/4 of the way in. I then put more antiseize on the threads and put the front plug in. I checked it when I put the car away this winter and so far, so good. No water has gotten in.

Bilal928S4

So you accessed the rear of the hole through the front. I am looking to access the rear of the hole from the rear (?) and I cannot find a way of getting to it.

NoVector

^^^ Correct - I used the tap as it was making it's way across Europe to clean the threads. I haven't seen the "tap" thread in a while so not sure what part of the world it's in now. Good luck.

martinss

I replaced mine with newer style rubber plug. Let's see that rust