Ol'fogasaurus wrote: ↑Sat Apr 04, 2020 9:18 am
"...It used a wave washer and a plate style self locking nut.....NOT the same as a nylock nut."
Ray, your post was very interesting. Again, the Nyloc style of locking nut has it's number of "on and off" re-use limitations which is quite low comparatively to the number of times a nut is addressed to on and off. It also isn't a for every use application either. I had never heard the nylon part of the lock giving bad torque reading before but it sounds plausible. "Castellated nuts", even when using the locking pin, also has limitations in use and dimensions.
The wave washer is pretty much a limited use washer and usually used (as you said) for low load/toque applications as it will flatten out quite quickly from either re-use applications or being clamped in place to long... pretty much the same with the heavier duty use split washer.
Lee
Yes!.....everything you noted is correct!.....and also why I got rid of ANY type of self locking nut from this assembly.
Back when I worked all of this out.....the idler arm ....and especially its crappy stock bushing drove me crazy.
I was driving my 412 daily....long distances just in the Atlanta and Dallas/Fort worth metroplexes.....which means my daily trips could range from nearly Gainesville in the North, to Desoto in the South to Fort Worth in the west...averaged about 200 miles a day every day. Mid week or evwry other week trips to Houston, Austin, Tulsa or Baton Rouge......well you get the drift. I drove about 3000 to 5000 miles a month in the 412.
The damn idler nut was about once a month tightening. The rear brakes were adjusted every 10 days to 2 weeks. Oil change once a month average. The fact that the roads sucked did not help. I worked on the car a lot.....every weekemd. A combination of regular maintenance and experiemntation for improvement.
I had to figure out what to do with the damn idler arm getting loose. New plate style lock nut from the dealer ($8).....did not help. An actual nylock nut....was actually worse.
Using an inch pound toruqe wrench from work and marking the nut with sharpy for visual....I got about 30 inch pounds (2.5 ft lbs) just to turn on the threads with the stock nut....and about 45 inch pounds (3.75 ft lbs) on the nylock nut. While that does not seem like much.....when your total amount of ft lbs is only 22.....thats significantly loose.
What happens.....is that you can feel the "wobble" start on a long highway drive....pull over at a reat stop and grab the torque wrench out of the trunk and retorque it. Next day....it's loose again. So you end up taking it to 30-35 ft lbs.....and the problem goes away for a week or so.....but when it comes back.....it now has noticable slack between the bottom of the bushing tube and the arm.
This was the tube "crushing"/ grinding down and/or wearing on the arm face. I found in these cases...the nut itself....because I marked it....had not come loose.
So....this crappy thin wall bushing tube turns out to be the 2nd of the two flaws....in the or8ginally defective design of the 411/412/super beetle idler arm bushing. This was before I ever figured out that the last two years of super beetle had fixed all of this by going to a bronze idler bushing.
The original bushing was both too soft....poor control....wore out its own rubber and the cneterl8nk bushings very quickly.....and it had the thin wall fast wearing bushing tube.
The only thing the bronze idler bushing did not fix is the gap between the step on the bolt and the face on the arm.....and....I only found out two years ago that there are two part numbers of bronze bushing....one with a shorter face that fixes this.
I got rid of the self locking washer and wave washer assembly may years ago. I went to a steel arbor shim that I file/sand to correct thickness to give me correct 30 ft lbs torque.....when the cotter pin lines up with the hole.
I went from dicking with the lock nut monthly to not having to adjust more than once in about 20-30k miles. When you do have to adjust....its because a small amount of the bronze....usually about .005"....has worn away. So spend 5 minutes with a file and an arbor shim and reset it. Done.
Ray
