Clutch bolts with or without lock washers

[WYDBODY1986]

I’m getting ready to reinstall my engine and tranny and noticed that the clutch I took out did not have lock washers on the clutch bolts even though they are shown in the PET diagrams. My question is are they needed? The clutch wasn’t a problem and it was installed by a shop I trust so now I’m wondering if they are needed. Yes I’m installing a new clutch and pressure plate .

[thetorch]

If you mean pressure plate bolts, yes to lock washers.

[winders]

Yes to washers...

But, split lock washers don't really do anything to lock the bolts in place. They are an idea that been proven to not work and in some cases actual help bolts loosen. I use quality bolts and Schnorr washers. I have never had a problem with the bolts loosening.

[gled49]

+1, what winders says.

[eastbay]

This lock washer begs to disagree, didn't think I would get it off.

[winders]

Originally Posted by eastbay

This lock washer begs to disagree, didn't think I would get it off.

https://engineerdog.com/2015/01/11/10-tricks-engineers-need-to-know-about-fasteners/

Lock Washers Are Useless! - Club Cobra

[WYDBODY1986]

Thanks for confirming my suspicions guys. I just don’t understand why the shop did not replace them when they installed the last clutch and PP. especially since they used new bolts.

[eastbay]

Originally Posted by winders

https://engineerdog.com/2015/01/11/10-tricks-engineers-need-to-know-about-fasteners/

Lock Washers Are Useless! - Club Cobra

That's what I love about the internet, having conversations just like being at a bar.

I provided photographic proof that proper split washers work and you reply with a couple of goofball links that were good humor, almost as good as memes.

1. All blanket statements are wrong (let's start with irony)
2. Engineerdogs theory is refuted quite well in the comments, and he agrees
3. The clubcobra post is just pointless shiess stirring, and there is certainly no consensus there at all. But they are bunch of funny guys.

but hey, you bolt your stuff together anyway you want.

To the OP, definitely use new lock washers since the previous shop lost them.

[gled49]

I don’t use split lock washers because of the destruction to the parts as visually evident in your pictures. Just sitting at the bar.

[winders]

Originally Posted by eastbay

That's what I love about the internet, having conversations just like being at a bar.

I provided photographic proof that proper split washers work and you reply with a couple of goofball links that were good humor, almost as good as memes.

1. All blanket statements are wrong (let's start with irony)
2. Engineerdogs theory is refuted quite well in the comments, and he agrees
3. The clubcobra post is just pointless shiess stirring, and there is certainly no consensus there at all. But they are bunch of funny guys.

but hey, you bolt your stuff together anyway you want.

To the OP, definitely use new lock washers since the previous shop lost them.

Carroll Smith said lock washers didn't work in his fastener book. He was a very smart guy with a lot of practical experience. He would not use them. He used regular washers or schnorr washers.

NASA Engineers are pretty smart. From NASA publication RP-1228, 1990, pp. 9-10:

[dannobee]

We use Nord-Locks at work. The test used for vibrating bolts is the Junkers Test.

https://www.youtube.com/watch?v=IKwWu2w1gGk

[PeteKz]

Cool. I wasn't aware of those lock washers. Now I gotta get some!

[proporsche]

Originally Posted by PeteKz

Cool. I wasn't aware of those lock washers. Now I gotta get some!

Yes ,quite solid washer......but i makes me wonder, how come they did not test wave washer?

Ivan
i will look for this nord w. here too;-)

[76FJ55]

Originally Posted by proporsche

Yes ,quite solid washer......but i makes me wonder, how come they did not test wave washer?

A little digging and you can find results for spring washers as well. for instance the sales literature from Schnorr, it shows the graph for a spring washer. this set of testing also showed that the split lock washer performed significantly better that previously referenced video.

https://content.hobson.com.au/category/schnorr/tech-schnorr-junker-test-results.pdf

it seems kind of interesting as they also show a ripped washer, which in this test faired rather poorly, however if you take a look at the video below, where they are promoting their RiPP Washer and RIPP Nuts, they display drastically different results.

https://www.youtube.com/watch?v=cg78FIZR3Xc

[proporsche]

Originally Posted by 76FJ55

A little digging and you can find results for spring washers as well. for instance the sales literature from Schnorr, it shows the graph for a spring washer. this set of testing also showed that the split lock washer performed significantly better that previously referenced video.

https://content.hobson.com.au/category/schnorr/tech-schnorr-junker-test-results.pdf

it seems kind of interesting as they also show a ripped washer, which in this test faired rather poorly, however if you take a look at the video below, where they are promoting their RiPP Washer and RIPP Nuts, they display drastically different results.

https://www.youtube.com/watch?v=cg78FIZR3Xc

interesting test on the youtube..have you noticed the nut stays and the bolt is actually loose inside the nut??No wonder all gets loose;-))))))

Ivan

[ryans65]

I work on cars for a living, this is anecdotal but I've never repaired a car that was the result of a split lock washer failure. I have had them fail while reusing them but sometimes hardware just needs replaced and isn't limited to just split lock washers. I don't go out of my way to use them though, there are plenty of washer options out there. Appealing to authority (engineers) here is laughable.

[proporsche]

Originally Posted by ryans65

I work on cars for a living, this is anecdotal but I've never repaired a car that was the result of a split lock washer failure. I have had them fail while reusing them but sometimes hardware just needs replaced and isn't limited to just split lock washers. I don't go out of my way to use them though, there are plenty of washer options out there. Appealing to authority (engineers) here is laughable.

i hear you;-)

Ivan

[dannobee]

Originally Posted by ryans65

I work on cars for a living, this is anecdotal but I've never repaired a car that was the result of a split lock washer failure. I have had them fail while reusing them but sometimes hardware just needs replaced and isn't limited to just split lock washers. I don't go out of my way to use them though, there are plenty of washer options out there. Appealing to authority (engineers) here is laughable.

Clearly, you've never raced.

[proporsche]

Originally Posted by dannobee

Clearly, you've never raced.

well, most of the pelican members never raced ;-) some do ...the point of this was why there were no washers on the press.plate at all;-)

personally in my 40 years working on these beasts,i have never seen any bolts loose ..no racing involved ..then again i did see some f..ups for sure;-)))

Ivan

[ryans65]

No I haven't, I've also never been to the moon or summited K2 while we're mentioning completely irrelevant things.

Originally Posted by dannobee

Clearly, you've never raced.