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Re: Crank Pulley Keeps Loosening

On Sat, 19 Jul 2003 09:53:32 -0500, snipped-for-privacy@stafford.net (J Stafford), who was sitting in a corner eating his Xmas pie stuck in his thumb and pulled out a plum and began to run off at the mouth like so:

>Appeal to net wisdom!
*giggle* *snort*

>I have four ACVW engines.
*jealousy*

On three of them removing the crank pully was a

>HUGE effort, but on one of them the thing loosens up every day! The >alternator belt is just right, and I tighten the nut very well each time >(the big screwdriver-stop and socket method. Actually, I use a bicycle >tire iron instead of a screwdriver because it is wider, blunt at the end >and has a handy curve.) > >Now I'm wondering if this isn't caused, in part, by the fact that I rev >this engine regularly to 7,000RPM and occasional de-acceleration from that >RPM (engine braking in the twisties) is causing the fan to drag back on >the crank pulley, loosening it.

I recently pulled my pulley off and replaced it with a sand seal pulley. Even though I did that recently I've forgotten for sure, but I thought there was a tab-like thingie that keeps the pulley from spinning around. Like once it's in place it won't spin (without turning the crank) even if the nut that holds it on is a little loose. If that's the case then I can't see how the de-acceleration you describe above could loosen the nut. Again, I'm not sure that *is* the case, though. Plus I only got a C in Physics in college.

There appears to be some kind of strange >dynamic in the fan shroud at high RPM that can cause air to 'stuff' and >brake an engine. Yes, it is a wierd speculation so straighten me out if >I'm wrong! > >I'm thinking it would be good to have a different means to fastening that nut.

I wonder if you could weld/JB-weld a thin washer to your crank pulley so that the hole in the washer matched up with the hole in the crank pulley...and then when you tightened the nut down you could bend up a corner of the thin washer so that it rested flat against one of the sides of the nut, keeping it from loosening?

-- Travis (Shaggie) '63 VW Camo Baja...

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corrodes the vessel that carries it.

Reply to
travis
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On Sat, 19 Jul 2003 09:53:32 -0500, snipped-for-privacy@stafford.net (J Stafford) scribbled this interesting note:

Seems to me that some kind of safety device could be used to insure the bolt does not loosen up. Even some kind of Permatex product could be used on the threads of the bolt to keep it snug.

First things first, is the bolt used or new? How clean are the threads? Is it a factory or aftermarket pulley (I forget, not having looked at your pictures lately.) Is there any kind of lock washer with the bolt (lock washer, wavey washer, etc.?)

Basically, more information, please...

Regardless of everything else, it seems that you have a symptom that is caused by some underlying problem. Any patch you perform without fixing the problem will cause the symptom to reappear, probably at the worst possible time. BTW, how to the various high performance engine owners address this issue? Have you asked Jake about it yet?

-- John Willis

Reply to
John Willis

.....I know when I was drag racing buzzy big-bore 2-strokes, we used to drill all bolts with a hole centered near the center of the threads where the nut would rest and thread weedwacker line into the hole..... Then we trimmed the line on either side a few mm higher than the threads..... The nylon of the line helped "lock" the threads without making removal a chore..... Not sure if this is helpful in your case but a thought.....

Sneaks

Reply to
Sneaks

Is it a stock pulley? If not, does the bolt itself bottom out? Are you missing a washer? And 7000 rpm's should have nothing to do with it. Sounds like the pulley is "giving" or the bolt bottoming out or even less likely,: the bolt stretching.

J.

Reply to
BergRace

Is it an original VW pulley? Or an aftermarket one?

-- Howard

1966 VW Beetle 1300 Deluxe -
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Austin Mini DeLuxe -
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Austin Mini Super DeLuxe~~ To email me, go to my website ~~
Reply to
Howard Rose

either a non-Genuine VW pulley bolt, or a loose flywheel.

John Aircooled.Net Inc.

Reply to
John Connolly

Please explain a little why?............I am very curiou so fthe conclusion and how it could be arrived at.

I understand the Aftermarket Pulley could be it, as the shape of the pulley can change due tocentrifugal force if its soft alloy. Just the flywheel issue is one I'd like a better understanding on. Thanks in advance.

Remove "YOURPANTIES" to reply MUADIB®

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Reply to
MUADIB®

It's an all new engine, John. I was talking to Jake Raby this morning. He said he's had a couple situations like that, possibly associated with the brand of pulley wheel. I removed it and cleaned the threads and used plenty of Blue Loctite, tightened to 40 foot-pounds and let it set while I adjusted the valves. I just got back from a three hour ride. I'm wiped out and cooling down so I'll check it when the sun sets. (These coupes... you know why they are call that? Because the driver is all cooped up. And hot!)

Reply to
J Stafford

Exactly. The key holds the pulley, not the nut.

Reply to
J Stafford

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