Broken Penske Clevis.

[boyitgobob]

<blockquote class='ipsBlockquote'data-author="TomInPA" data-cid="1343575" data-time="1476801084"><p>

I heard back from Eric Trinkley at Penske Motorcycle Dept, in reply to an email with the image attached.<br />

<br />

<blockquote class='ipsBlockquote'><p>Tom,<br />

<br />

Glad you caught this before anything happened.<br />

<br />

Yes we will cover this under a warranty claim. We will get one shipped out to you. Is that your shipping address you included in your email?<br />

<br />

Thank you<br />

<br />

<em class='bbc'>Eric Trinkley</em><br />

<em class='bbc'>Motorcycle Department</em><br />

<em class='bbc'>Penske Racing Shocks</em><br />

<em class='bbc'>Custom Axis Shocks</em><br />

<em class='bbc'>150 Franklin Street</em><br />

<em class='bbc'>Reading, PA 19602</em><br />

<em class='bbc'>United States</em><br />

<em class='bbc'>Office: 610.375.6180 </em><br />

<em class='bbc'>Fax: 610.375.6190</em><br />

<em class='bbc'><a href='https://www.penskeshocks.com'>www.penskeshocks.com</a></em><br />

<em class='bbc'><a href='https://www.customaxisshocks.com'>www.customaxisshocks.com</a></em></p></blockquote>

<br />

Life is good, and it appears I may be spared shipping the broke part back. BTW the FSM calls for a 29 ft-lb torque on that bolt.</p></blockquote>

Tom, please compare old and new to see if they made any dimension changes.

 

[mcatrophy]

... it would be a general error showing it's warts in a more widespread manner..

It's "its" dammit!

... Learn something.

 

[wheatonFJR]

... it would be a general error showing it's warts in a more widespread manner..

It's "its" dammit!

... Learn something.

I would take your criticism to heart, but y'all say stuff like colour, defence, lift, WC, etc, so it's hard to say which way I should lean on this one.

I stand by CLEVIS, so put that in yer pipe and smoke it.

 

[mcatrophy]

... it would be a general error showing it's warts in a more widespread manner..

It's "its" dammit!

... Learn something.

I would take your criticism to heart, but y'all say stuff like colour, defence, lift, WC, etc, so it's hard to say which way I should lean on this one.I stand by CLEVIS, so put that in yer pipe and smoke it.

Clevis is correct. Unfortunately, even my English English spell checker tries to convert it to "clovis", so I have a little sympathy for the OP. Mainly because he's got a broken one.
Anyway, as far as "it's" and "its" are concerned, it's the same in both our languages; "its" is the possessive pronoun, it doesn't need the possessive apostrophe. Just like "his" [you wouldn't write "hi's", would you?]. "It's" uses the apostrophe to replace missing letters, it might be used instead of "it is", "it has", "it was".

About 95% of writers seem to get it wrong. So you're in good (bad?) company. Which doesn't make it right.

 

[wheatonFJR]

It's all right. Thanks for the lesson...I'm always willing to learn sumpin.

 

[0Face]

It's all right. Thanks for the lesson...I'm always willing to learn sumpin.

Dammit, where's that picture of you in your underwear when we need it!

 

[wheatonFJR]

It's all right. Thanks for the lesson...I'm always willing to learn sumpin.

Dammit, where's that picture of you in your underwear when we need it!

Hey, I learned my lesson...never do something on a lark. What seems funny at 6:30 am may not actually be funny.

All my actions are now well measured and prudent.

 

[TomInPA]

I stuck my broken clevis back on the bike and rode 150 miles in the beautiful Fall color and warm 84 degree temperatures. Some things are worth the risk.

 

[wheatonFJR]

^^^^

Beautiful colors!

 

[Fred W]

Yes, nice colors, but I'd have probably shoved the old stock shock back on for the ride.

It may not have handled quite as well, but it wouldn't have broken and killed ya'. Jus' sayin'.

 

[hppants]

Slight thread jack, but I enjoyed seeking out and finding many covered bridges on my recent trip to New England. That was a first for me, at my 50 years young.

However, I did not find a red one, and admittedly, that was a little disappointing. I shall seek to correct that one day.

Now back to our regularly scheduled Clevis discussion....

 

[Ignacio]

Slight thread jack...

Management hint as we go into the cooler weather. If you utter (or find yourself thinking about uttering) those words....you're off-topic.

Don't do that.

Everybody, please keep this thread about the subject listed in the title.

Thanks

The Management

 

[BakerBoy]

Anyone with such a broken clevis able to post high-res pictures of the fractured face? Several pictures with lighting from different directions would help. The pictures a few pages back are fuzzy and not high res enough. Fractography [by a trained eye] can be very helpful to determine initiation site and speed of progression of the failure.

 

[FredandJeannesRacer]

The pictures posted show that the oem clevis has a radius where the thread joins the u shape, making it stronger.

 

[TomInPA]

The lack of radius in the Penske clevis is probably a root cause, aggravated by the radius of the final thread as noted by Gerauld. As this thread has progressed, we become aware of more and more units that have failed at some point, including our intrepid leader Iggie. I appreciate Penske's support, but it's a lot cheaper to warranty the part than to recall...JSNS.

I will try to get the Nikon on the broken part later this week. I can shoot very high resolution (6000x4000), but let me know if you have specific lighting requirements. My other pics were just with the iPhone 5.

 

[Cav47]

So, for review..... I think we have established that the part has a weakness. Also established is that using the wrong hardware can break your stuff. Someone "special" can even have a failure 2 times. Penske will likely help u out with a warranty. Thank God it doesn't cost $250. You might not know it is broken unless u really inspect it. There is a torque spec on that bolt. I don't have a torque wrench though. There are some serious super smart nerds about all things FJR. This board is full of people who want to help others. The English language can be hard to master regarding Clovis, clevis, and punctuation regarding it's and other stuff. Some people are bored at work and are good at photoshop. I am sure I missed some good points by others in this 5 page thread. But all this happens because of collective knowledge of this board. I am very thankful for all the help fixing this and all of life's other problems.

 

[BakerBoy]

Tom,

It depends on the fracture surface, shapes, and crack propagation orientations as to what the best lighting will be. But in general, both 1) lighting directly onto the face of the fracture (no shadows created by the peaks of the fracture surface) and 2) lighting from each of the fracture's sides to show the various peaks (highlighted) and valleys (shadowed) of the fracture surface can all be helpful. Using camera Macro mode so that the fracture face takes up most of the area of the image while keeping the surface in focus is best, if your camera allows. I may be able to call on a favor from someone who's expert once the images are available.

Being an engineer, I too see the notch at the base of the threads and know that is a relative high stress spot in the clevis (as garauld's image in post 71 illustrates even without the stress concentrator of the last thread)--I wouldn't design such a part with that stress concentrator at the junction of the threaded rod and the clevis. But to be fair, that doesn't mean its the failure site. There can be other factors: alignment of the clevis to the tang it mounts over, squeezing or spreading of the clevis when bolted in, features of the fastener itself, inferior material, undersized part, a sudden large force, and more all can be at play.

As I'm not familiar with the FJR shock, is this failed clevis at the top or bottom of the shock? Or elsewhere in the suspension linkage?

 

[Cav47]

Bottom of the shock.

 

[RaYzerman19]

A correction to my earlier post...... I found a bolt that came with a replacement suspension pivot I have. This bolt was quite long, and has a lengthy spacer, lengthy enough to protrude outside of the clevis.. The pivot spacer I mentioned at 1.2" is the shock spacer, which is slightly longer than the inside width of the clevis (~1.18"). The idea would seem that the spacer is inserted through the large hole of the clevis, then the shoulder bolt through that. Ideally, the combined shoulder/spacer is long enough to prevent the head of the bolt from putting any side pressure on that side of the clevis. My extra bolt with long spacer would easily accomplish that and the head would not even be close to touching the clevis......... in other words, it seems the clamping is all done on the nut side only and there is no squeezing of the clevis. Similar in concept to your front and rear axles, which clamp everything to the left side.

In looking at the OEM Gen3A, it does look like the head of the bolt at least contacts the clevis, but parts diagram shows it to have a separate spacer, not a shoulder...... that clevis however looks to be steel with the shock shaft welded to it. When I get a spare moment, I will pull my bolt out and do a couple of measurements.... perhaps the answer is putting a washer on the threaded end of the bolt (inside the clevis leg) which in effect makes the spacer/shoulder longer/head of bolt will not contact the clevis. The Gen3 has a washer also under the nut..... torquing it up snug/to spec wouldn't stress the clevis. The nut does have a locking feature.

 

[Fred W]

Maybe a couple more, important takeaways here:

In the latest two cases the correct hardware was found to be in place, and so incorrect hardware was not the cause.

In these 2 cases the break was on opposite sides of the clevis yoke, one on the small hole side, the other on the bigger hole side, proving it can occur on either side

In both of these cases the break was near the large threaded stud that connects the clevis to the bottom end of the shock. It would be good to know if they all break in this location, but 2 out of 2 is a good start.