Can-Am Stress crack detection

[badassmav]

While inspecting the hubs on our Maverick, I noticed what appeared to be stress cracks propogating from the sharp edge (stress raiser for sure) of the foolishly drilled holes in the center of the hub, used only for the purpose of holding on an aesthetic plastic hub nut cover. Following, is the lay-mans process to confirm such a crack is real. Since stress usually is highest on the surface of a stressed component, visual signs of structural cracks usually show themselves before manifesting themselves into a catastrophic failure. Here, I apply a 3 step process using aerosal chemicals. First, thoroughly clean suspect area with a wire brush and contact cleaner. Then, apply the dye penetrant, allowing 1-30 minutes for it to dry. Next, wipe excess dye penetrant clean with provided cleaner and a clean rag. Then, spray a thin film of the developer on, and in a few minutes, it will exagerrate the dye penetrant that found its way into the crack, and PRESTO! So, be warned Maverick owners of this area of poor engineering. In their defense, Can-am now offers an alternative hub that replaces the vulnerable "spoked" design with a full diameter casting, and DOES NOT have any of the stupid holes drilled through the highest stressed area of the component. Enjoy.

 

[PickupTrucker]

interesting

 

[crazywatson]

My uncle use to magnaflux all the important parts of there desert car every race. I wonder how many other teams are checking for cracks every race?

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[badassmav]

My uncle use to magnaflux all the important parts of there desert car every race. I wonder how many other teams are checking for cracks every race?

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We usually send out the stressed parts for magnafluxing, but I came across this crack last night while prepping our pre runner for a test today and had no time. I am still trying to determine a service life for the stressed components on the race car. I guess I just learned how many miles NOT to put on the hubs! When Marc was racing trucks, they'd send out the spindles, steering arms, and other similar type parts every race also, and most every time, there were cracks to repair. It also helps when you know WHERE to look for cracks, and in what areas cracks are most likely to manifest themselves. What was/is your uncles name, and what series did he race in?

 

[Simi Dude]

Great info Reid, thanks for sharing.

 

[Blue Coyote]

Thanks for posting thus - was gonna order new hubs this week and it's good to know about the non- spoke hubs.

 

[crazywatson]

Russ Miller he ran a class 9 car in the 90's with his brother Ray. It's a poor man's class but still cost a ton of cash to run SCORE/HDRA I use to go and help in the pits. It was awesome and I really enjoyed it. They have 5 brothers and have been in the desert for years. Grew up in Santee. My cousin Tyler raced i think it was class 10 a few years back for awhile too.

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[the stripping shop]

me and my helper were just talking about that stuff. was wondering does it work on aluminum.

 

[BiggJim]

me and my helper were just talking about that stuff. was wondering does it work on aluminum.

Yea...Its just a bleed test. The red Dye will bleed into any crack in a surface. I used it all the time in my old job. We were using it on Inconel and stellite weld overlay parts. Its really a pain in the ass on anything that isn't finished machined.

 

[badassmav]

Yea...Its just a bleed test. The red Dye will bleed into any crack in a surface. I used it all the time in my old job. We were using it on Inconel and stellite weld overlay parts. Its really a pain in the ass on anything that isn't finished machined.

It will work on any solid metallic-based material. Nickel, bronze and carbon alloys, and non-ferrous (aluminum) materials as well. Jim is right about being a pain in the butt. It is messy, and timely to use, and if not used properly, results will be inconsistent, even bordering on inconclusive. He is also correct in that it works best on smooth surfaces or machined parts. On rougher surfaces such as castings and forgings, results will be deceiving since it will fill in the tiny undercut line where the filler material meets the base material, right at the heat affected zone. To better understand this, look at the welds on most any mass produced steel frame that is MIG welded (most all UTV's fall into this category). Notice that it appears the welded joints have cracks around the perimeter of the weld, where the weld bead joins the adjacent tubing. This is the fine line that the dye penetrant will fill in, resulting in a false positive test.
Since the majority of cracks will always form on the surface, and start from a corner, burr, or sharp edge, it is usually just as accurate to clean the part thoroughly and visually inspect it. I posted this thread more so to warn the Maverick owners of a weak link in tne drive train than to demonstrate, or advocate, the use of dye penetrant as a method to test for cracks. I'll follow up this post with a pic of the old, lame hub, and the new replacement hub as well.

 

[badassmav]

Following are 3 images. 2 of the old style Maverick hub, and 1 of the new, full diameter casting. Note the holes in the back side of the "spoked" style hub. Not only is the drilled hole not de-burred well, there is also a diameter cut machined out that removes material from only 1/2 the hole, and it too could use a bit more be-burring to eliminate stress raisers.

 

[Factory UTV]

Good info Reid, thanks!

 

[madviking]

Great post. If folks are really interested in failure points and building UTVs that don't have so many, pick up a copy of Engineer to Win, by Carrol Smith. About $27 and will save your a$$.

 

[badassmav]

Great post. If folks are really interested in failure points and building UTVs that don't have so many, pick up a copy of Engineer to Win, by Carrol Smith. About $27 and will save your a$$.

(Caution: Boasting ahead ). That is great advice! His (Smiths) was the first book I purchased and read before building my first race car (truck) back in '89. As a result, the first race car that I ever built, won a first place overall finish, in its first race out of the box . All of my friends (yes, I actually had friends back then) thought I was the bomb. Reading his books was like taking a smart pill for my minds insatiable appetite to know and to understand. Carrol Smith's "Win" series' publications should occupy every fabricators bookcase. He has an amazing way of over simplifying the complicated world of nano physics, and can turn any hungry mind into an arm chair engineer in no time. Actually, most everything that I spew out across this forum is a result of his writings, and my successful application of them. It is his no nonsense "it has all been done before" mentality that is the motivation for my sharing everything I do and learn here in this forum. My work is based on the sound engineering principles that he unashamedly shares. Great contribution to the thread. Thanks madviking!

 

[Blue Coyote]

Carrol Smith books are a must read - the time spend removing stress risers and points is often underestimated.
Thanks this hub info! Is that the new standard replacement or a Max hub?
You having any issues with the rear outer CVs failing at the threaded area? And if so can you share your findings. PM okay too.
Thanks

 

[badassmav]

Carrol Smith books are a must read - the time spend removing stress risers and points is often underestimated.
Thanks this hub info! Is that the new standard replacement or a Max hub?
You having any issues with the rear outer CVs failing at the threaded area? And if so can you share your findings. PM okay too.
Thanks

I'm not sure if the 'full diameter' casting wheel hub is for the Max or if it is a replacement for the old style. Last time we ordered hubs, that is what was sent. The BRP online micro-fische
http://parts.can-am.brp.com/Index.a...p5o6s71f1&catalog_id=0&language_id=1&siteid=1
doesn't picture the new style. It only shows the cluster styled one, but I'm sure I ordered the new hubs from the old p/n, and the p/n for the 2013 Maverick 2 seater is the same as the part number for the 2014 Max 4 seater. That being said, yes, it probably is the new replacement. (the Jagged X guy was right, based on this lengthy response, I do have too much time on my hands!)
Regarding the rear, outer CV's, I know the WORCS and other short course guys are having troubles with snapping off the stub axles at the threads (I think where the diameter changes when the threads meet the splines). We have never had any issues in that area, but perhaps you can learn a bit from a discussion that I had a month or so back on this forum:
http://www.utvunderground.com/forum/showthread.php?t=14364&page=2
The BRP engineers recommend that in racing applications, you use a larger diameter hub nut, which has a larger bearing surface, and increase the torque of the hub nut to 200 ft./lbs. Be sure there is no grease on the threads when torqueing the nut, or you risk yielding the section of the stub axle adjacent to the threads (harware tech, another category well covered by Carroll Smith in "Engineer to Win" as well as "Prepare to Win"). In addition to this, they recommended filling in the splines on the wheel hub with red (271) Loctite prior to assembly. The machining tolerance seems to be excessive here. We have been following their recommendations precisely since day 1, and have had 100% success with it. Our current rear stub axle/cv joint body has over 1,200 hard race miles on them, on a 2,000lb. + car with 30" tires, without failure. The only variation I applied to their recommendation, was I used a larger diameter flatwasher behind the hub nut for increased leverage and bearing surface. If I recall correctly, I think the OEM washers used on the sway bar arms were the ones I used. Be sure when installing the washer, that the convexed side faces outward, so the outer diameter of the washer is what is bearing against the face of the splined hub.
To avoid using heat, and potentially damaging your wheel bearing grease and seals when removing the now Loctited wheel hub, you will need to fab a removal tool. I'll attatch pics of the tool that I made, as well as the over-sized hub nuts that I am using. I welded a used hub nut on my removal tool, since I already have the 32mm socket out to remove the wheel hub. The tool also uses 2 of the lugnuts you removed when removing the wheel, to work (like the "Church Lady" says, "How conveeenient!). Good luck, and thanks for taking your time to read my babbling!

 

[badassmav]

I would like to take this opportunity and say that, with the exception of modified (lengthened) half shafts (axles) and drive shafts, the Can-am Maverick that we compete with and have won races in, and our 2 pre-runners as well, use 100% genuine OEM drive train components that we purchase directly through BRP.
The old style wheel hubs referred to in this post have served us well for over 3,000 grueling miles, and are only now showing signs of fatigue. Likewise, the stock wheel hubs on our race car have over 1,200 reliable race miles on them. These wheel hubs were designed for recreational use, not racing, and have stood up well under the most extreme of conditions.
At times, I tend to strike the nerves of entities who might read my postings, so I just wanted to clear the air regarding the durability of said components, as well as our confidence in them. In racing (and believe me, Marc pre-runs like he races!), all stressed components have a service life, or a maintenance schedule to assure ongoing reliability. We are new at this, and are still determining those parameters. I apologize if this thread has offended any of our supporters in any way. B.A.M.

 

[Blue Coyote]

BAM - absolutely appreciate you responces - just wish they were more indepth -just kidding, the info is really helpful.
Am ordering new rear hubs and axle assemblies. Working on a deal to have the rear outer CVs and hubs cryo (cryogenicaly) treated. Will also source larger dia nuts as well. Hoping this combo will address the issue.
Keep on posting!

 

[badassmav]

BAM - absolutely appreciate you responces - just wish they were more indepth -just kidding, the info is really helpful.
Am ordering new rear hubs and axle assemblies. Working on a deal to have the rear outer CVs and hubs cryo (cryogenicaly) treated. Will also source larger dia nuts as well. Hoping this combo will address the issue.
Keep on posting!

Yeah, that's the new thing nowadays, cryo treating. I know nothing about it since it was not around, or at least available to the masses, when I quit building cars 23 years or so back. I heard that Gorilla offers aftermarket stubs, but the word is thety are still working out the bugs on them. Another member told me they are working w/ Summers Bros. on some trick 4340 alloy stubs with a larger threaded section, but I can't recall who it was. I'll review my past posts and get back to you. More in depth-your'e a funny guy !

 

[crazywatson]

I hear cryo treating the cv's works real good to keep them cool. I'm surprised I don't hear more about it. Or maybe that's a team secret for the people doing it?

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