StratfordShark

I want to replace the deformed rubber buffers on the airbox with new ones.

In the past I've removed these by cutting/pulling off the rubber, and then turning what's left at the bottom by gripping with pliers. That was with the airbox brackets off the car during an intake job (previous S4).

I wanted to leave the brackets on which the buffers thread in on the car, and try to find a more elegant way of removing them. Problem is when you apply any torque the rubber starts shearing, and in the past the rubber has always split on me before thread has broken free.

I wanted to try the "double nut" method which is meant to be good for studs. You thread on two nuts, tighten them to each other, then just put a wrench on the lower one.

This is where I'm confused. When I put a wrench on lower nut and try to turn it out, the nut above it wants to turn in same direction too, even if I'm careful not to keep the wrench clear of the upper nut. The upper surface of the lower nut drags the upper nut with it and they are both happy to unscrew from the stud.

I'm obviously missing something simple here. What is the correct technique please?

If the "double nut" isn't appropriate here, then what's the best way of undoing these buffers from the brackets? They seem very tight. I did apply some PBlaster and leave for an hour before I tried to turn them out. Heat is not an option as not only are fuel lines close, but the metal stud is interrupted by the rubber so I can't just apply heat to the upper thread.

the flyin' scotsman

Adrian............the double nut process is as you describe except you have to 'lock' the 2 nuts together. This is done by holding the upper nut in place while tightening the lower nut to it with a spanner. With the nuts locked apply force to the lower nut in the correct direction to loosen CCW in most applications.

Not sure if this will work with rubber stud, go careful.

StratfordShark

Thanks Malcolm. I'll have another try tomorrow but you're likely correct that it won't work with the rubber. I think I'll just have to hack the things apart like last time!

danglerb

Old rubber won't break loose old threads, and if you aren't keeping the old part, pliers right on the base is what I would try. The idea is to grip the sides of the flat "head" of the metal stud where its glued to the rubber.

Double nut requires the two nuts to be tightened vs each other using two wrenches.

Landseer

The base nut on these has a centering shoulder that fits into the bracket.
I had to bite the bullet on them, pull the bracket bolt into the water jacket, and put them in the vice. That 11 mm nut just really holds tight when also embedded in the bracket.

Then I had to hold the metal beneath the rubber, against the bracket, using either a stilson or vice grips.

Don't think the double nut method will help here.

928autobahndreamer

I just did this on my 87, and it was way more work than I ever imagined it would be. I tried to grip the base with a pair of vice grips, but it would slip off. I could not believe how tight that was on. I had to ultimately dremmel off the top and twist out by gripping the bottom threads and screwing out downward. The drivers side came out fairly well with this, but the passenger side had to be drilled all of the way through and then chase the threads with a 6mmx 1.0 pitch tap.

After all of that, the new ones went in perfectly. But, still it was one of those little jobs that was 30x more time consuming than you would ever imagine.

jpitman2

Try double nutting on the thread that you want to loosen (lower on in your pic), that way the rubber is not involved. You also want to turn the nuts , looking at your picture, anticlock looked at from above. Obviously once you have the stud moving, you would need to unlock and remove the nuts so you cans crew the whole thing out through the bracket.
jp 83 Euro S AT 52k

RKD in OKC

Have the same sort of rubber mounts on a pump on my Range Rover. The Rover mounts even had a washer thick hex at each end of the middle rubber bit. After shearing the threads off one, and breaking the rubber on the other I gave up trying to preserve them and bought new rubber mounts for $8 each.

LostInSpace

Adrian - Had the same problem with the rubber shearing when doing my Intake last year. Found it quickest to rip off the top stud as you've previously done, remove the remaining rubber so you have the metal from the lower stud exposed. JB weld on an old bolt, heat the bracket and use a spanner on the bolt - this gives you much better leverage and the stud should release easily.

Good luck!

928autobahndreamer

JB weld. Now why didn't I think of that.

Good idea for next time.

StratfordShark

Well that wasn't too bad. I could see it was actually turning out with pliers on base of support (right hand side), but angle was awkward so I just removed one intake nut there which holds bracket in, and was able to turn it out with long pliers with bracket in my hand. Very little damage to the support but you can see the characteristic shearing which makes the airbox fiddly to refit.

I've left the other side in for now as I've ordered a pair of new supports (931.110.191.00) but won't try to remove the other support till I have the parts as there's a car event at the weekend and I don't want to be stuck waiting for a new support. Removing the bracket on the LHS is more involved as the fuel damper/fuel rail union sits over it, and I don't want to start dismantling stuff for such a small job. I'll tear this buffer apart and I've found that one of my Irwin bolt extractors fits well over the flat metal base so should make it easy to turn out.

Shame I had to order from Porsche as I got hold of a few of these supports from a model boat parts supplier on eBay (I think they're used as vibration mounts for model engines). They were M6 but the rubber body is 15mm long compared with less than 10mm for the original (hard to be exact with the shear). If the body is too long then I don't think the bottom of airbox would be a snug fit on the MAF. Looking around I can't find mounts of the original size anywhere but from Porsche.

shmark

Anyone know if these will retrofit to a 16v car? I replaced mine last year but the only option was a rubber isolator I bought from McMaster-Carr. The 16v standoffs are NLA. It's pretty good, but not exact - little harder than OEM and a slightly shorter length I have shimmed with a washer.

Bizman928

Hi Adrian
Glad you got your rubber Mountings off. Give me a shout if you haev any more troubles and I could have popped down today as I was passing to give a hand.

Steve

StratfordShark

Thanks for offer Steve!

Just back from picking up various parts including the buffers. Here's a comparison of old and new. I seem to recall that the old buffers on my previous S4 were deformed worse than this. Note also the corrosion in the old threads where they screw into the bracket, which is how they get to be so tight in there.

For anyone who wants to try to find these mounts from another source, the body length of the new M6 mount is 8mm. Diameter around 17mm but length is critical measurement.

They were also used in 911s 1987-89 (maybe the 930 Turbos given the p/n?), and 924 1976-79 and 1980-85 (my parts guy at Porsche thought they were 924 Turbos)

Richter12x2

Also, for future reference on removing these, when I had to get mine out, I just used a hacksaw blade to cut a notch in the bottom metal piece (under the rubber) and used a big screwdriver, and they popped right off. Saves a lot of drilling and swearing!