yelcab

I have the strangest issue with a 997 belt tensioner arm / pulley yesterday. I had to replace an oil filler tube so the belt had to come off, then the alternator, then access to the tube bolts were possible. Then on the way back, I went to lever the 24mm nut on the pulley to install the belt, the big 24mm nut and the 15mm bolt on the back of the arm spin and therefore no levering force was applied to the arm. I went to put a 15mm wrench behind the pulley to hold the bolt and tighten the nut and rounded off the bolt as well as rounding off the corners on the 24mm nut. Wow.

So, now the throttle housing, AC compressor, PS pump had to come off in order to get access to the Power Steering pump bracket to come off. I am going to WELD the bolt to the arm so that it cannot spin. The levering force applied to the 24mm nut will push the arm against the spring inside the tensioner and provide clearance for the belt to slip on. I am also replacing the pulley and the big nut that comes with the pulley.

Anyone see any potential issue with this solution, or have seen it before?

Quadcammer

that bolt/24mm nut should be red loctited (and are from the factory). I agree its an asinine design, but I'd guess there is a reason for it. Not sure if welding it is a good idea.

When loctited and appropriately torqued, the tensioner works as designed.

yelcab

Well, couple of notes:

1. Welding it does work, as long as you weld the bolt straight. On a bench vise, it pivots nicely now with the wrench applies to it.
2. For future owners, removal of the PS pump bracket is NOT required in order to remove the pivot arm from the tensioner assembly. Just simply unbolt a small M6 allen bolt from behind at the center of the spring tensioner housing. Then pry out the arm toward the rear of the car. To remove the spring tensioner assembly, you do need to remove all that crap to get access to one of two allen bolts holding the tensioner housing to the bracket. Now, THAT is an asinine design. I'm glad to see the 997.2 tensioner is entirely different. It seems Porsche learned that lesson after 10 years with the 996 and 997.1

I am still going to replace the pulley and tensioner anyway because they are out now and the plastic pulley is very worn out on the plastic bit.

Tj40

Sorry - to clarify I assume you have a 997.1??

yelcab

997.1, correct.

Petza914

My tensioner nut has those same rounded corners from a PO where it won't hold a wrench or a socket. I either used a prybar or a grip clamp to move it where I could get the belt installed. On mine, it's like the nut isn't protruding enough from the pulley to support a socket properly working on it and I tried a few different types of sockets before moving to the pry bar or clamp method.

yelcab

They could use a thicker 24mm nut design, for sure.

Quadcammer

The rounding of the thin 24 generally happens because sockets have a taper right at the top. You can grind that off the socket (maybe 1.5mm) and that greatly reduces the chances of rounding it.