Paulyy

A few times now my crank bolt has backed out. It's caused a few issues.
I've replaced the pulleys. Oil pump seals and sleeve.

My belts aren't to tight either. Feels to be appropriate.

This is the third time.
Last time it happened is when I changed out everything. And even loctite the bolt in.

All the pulleys are in nicely. Just the ps pump pulley is loose.

Ideas?
Thanks in advance.

divil

Have you ever replaced the bolt? It might have stretched permanently. Once that happens it will not hold again.

https://www.fastenal.com/en/77/reuse-of-fasteners

V2Rocket

did you put the big f**king washer in the right direction?

Paulyy

Never replaced it. Might have to. Didn't know this. Thanks.

Yep.

Tom M'Guinn

All that other stuff, plus... are you sure you are torqueing to spec? Most hardware store torque wrenches don't even go that high and get pretty inaccurate at the end of their range... Weird issue, however, as I've only ever seen them get tighter over time. Does your motor have weird harmonics/vibrations maybe? Sure you have the oil sleeve and o-ring and other stuff all on in the right order? Take a close look at the crank threads, bolt and washer for clues...?

V2Rocket

what're the odds the crank nose itself has stripped threads?

Spidey944

After having backed out a few times, I am sure the threads are a bit worn from the vibrations

Paulyy

No vibration from what i know of. all i can say for vibration is in 3rd gear there's a slight vibration from the trans. that's it. engine is smooth.

we torqued it as much as we physically can (to spec) with breaker bar and extensions.

oil sleeve ect are all in correctly. for a fact, when bolt came loose, only the oil pump pulley was loose. other pulleys where on the shaft nice and firm.

The bolt had loctite on it, so when tighting back up, it was quite hard to turn. couldn't turn it by hand.

Tom M'Guinn

I wonder if old caked-on loctite is giving false torque readings/sense. If nothing else, I'd clean the threads and make them as pristine as possible... If there was old Loctite in there, then chances are there was some grease and crud too, none of which is good for keeping bolts in place.

slap929

155 ft/lbs or 210nm for the torque. I have had mine come off once before. Glad I was not to far from home.

reno808

It might not be torquing it properly. Are you accounting for the extensions ?

KevinGross

Agree, replace the bolt. Get it from Porsche, cheap enough. Should not need thread locker but do torque it properly.

Dave W.

Also check the sprocket and oil pump gear to make sure it's not deforming and being crushed.

SirLapsalot

Definitely. Anything that adds friction will reduce the clamp load for the same install torque. That bolt isn't supposed to have loctite so I would clean it all out of the threads.

Sounds like the bolt isn't being torqued properly. No breaker bar should be used at all. Just a torque wrench.

ehall

So, where in the hell does one get/rent a torque wrench that goes to 155 ft/lb's, in the U.S. without taking out a second mortgage?