underdog928

While just trying to tighten the upper idler bolt that holds the lower idler arm on the water pump, it just snapped. I was tightening it by hand with a 3/8" T-Handle and all of a sudden it got really loose. Before you start, I do have a good hand feel for torque as I'm usually on the weak side and then I use a torque wench to get the bolts up to spec. This is/was a bad bolt.



Thank God this didn't happen when the car was running!

Just a safety note to everyone - CHECK YOUR BOLTS for fractures. Although I'm not sure if I would have caught this with a visual inspection.

JHowell37

This bolt should be a standard replacement item when replacing a timing belt on the '85/'86. Vendors wake up and put this on your lists of suggested parts to replace with the timing belt. Many of them are bent or fatigued when removed. It's better that you broke it now, instead of having it break a timing belt down the road.

underdog928

Got that right!

Big Dave

Just having it bend can lead to disaster. Been there done that.

JHowell37

Every time I think of that bolt, I think of your car.

Dave928S

Those bolts are a disaster waiting to happen. Even a brand new one has a built in waist point (root of the thread) right at the step. They remind me of those security bolts which are designed to have the head shear off at a certain torque, which also have a reduced diameter point designed to fail.

Standard replacement part? .... you betcha ... I think even one use is stretching it ... maybe literally.

Imo000

I've seen those bolts on ignition locks on Hondas. Why the f&ck didn't Porsche made the pivot bolt holes just as thick as the rest of that bolt?

928 Is My Favorite Time of Day

Or install the Porkensioner and eliminate the problem all together.

Jim Devine

Has anyone here tried getting an oversized shoulder bolt
made with 10mm (or?) threads & getting the boss on the
water pump re threaded?
I have an 86.5 that ready to go back together & I
keep looking at the factory shoulder bolt- it is only
6mm +- at the base- scary.
I would like to keep the factory belt tens warning system.
I bought all new everything, wp, rollers, bushings etc so would like to use them.

Does anyone know what grade material the factory shoulder bolt is? IE: 8.8, 10.9 etc?

I'm considering using a 10mm allen (12.9)
& pressing on a sleeve to make it into a shoulder bolt.

Anyone done something like this? Results?

Thank You

Imo000

and eliminate the factory warning system too?