Super fastener holding ability needed

Well yes it is OT, but we all need fasteners to hold. The suspension under my high powered snowmobile, due to my 230 lbs. and hitting bumps at high speed has multiple points where the fasteners don't want to hold. Part of it is due to holes in the side rails that are slightly opened up due to wear when a fastener has been loose. My plan currently includes drilling egged out holes and inserting steel bushings. Rather than just replacing Nylock nuts with new, I plan to put star type locking washers under them. I plan to put in new cross shafts with the bolts going into them, with red Locktite instead of just the blue that comes on them from the factory. Of course I know that if I lost weight I would have fewer problems, but I am waging a constant battle on weight gain and every time that I lose a pound instead of gaining one it is a major victory.

I think all your efforts will help but imo,star washers will help control wallowing holes
out farthur if drilling out holes will be time consuming. In addition to red Loctite,higher
grade and fine thread bolts should help also.

If possible, double nuts work well.

Hello showcrop,

A couple of things you need to do. First you NEED to drill the holes to the next size. Then use new bolts
and nuts, nylock nuts would work best! Also you should use at least grade5 fasteners. Grade 8 is of course a better
choice. The bolt shoulder should be long enough to to through so that you need washer to be able to thread
the nut. Flat washers should also be of a good grade. And finally the proper torque. I know I said a couple
of things. But you do the above, it will be better then new. AND.... if it was my machine and they got
loose againg. I would repeat the above process with the next size fasteners. If I was doing the repair, I would be drilling slow or using a reamer drill, so as to keep the holes the proper size.

Guido.

Your post doesn't mentioned if your problem is on the slides skid itself of ib between the snomobile aluminium body and gussets holding the whole suspension. In the last case, I would try to add a Very High
Bound (VHB) tape made by 3M. This tape has a very good bonding capacity but in top of that, it allows tiny movements in between parts which made gussets mauch more stronger than before. Again, you need large
enough surfaces to go this way?
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My thinking is that you have a machine/unit problem - quality. I have a pal that is well over 270# and uses his Snow Machine/Skiddoo/whatever, every opportunity. What is the frame made of ? Your idea of repair sounds good, but I don't think that is the main issue. HTH

Take them to a welder and have the holes welded shut ane re-drill them. I've done hundreds of those for that reason. I'm not sure about drilling them larger and putting in steel as too muxh material willl likely be removed. You won't need the rest of your 8deas if you do that and just keep the parts tight. It is the parts getting loose that causes that. I used to spend a large percentage of my winters welding snowmobile parts.

Many in engineering circles view lock nuts, lock washers, threadlocker, and the like as a band-
aid for a fundamentally poor bolted joint design. One of the most important things is to have
sufficient length of bolt available to stretch when torqued. A long bolt stretched to just below
the yield point will stay tight long after an equally-torqued short bolt comes loose. For this
reason a bolted joint of two thinner pieces of material that is subjected to vibration or impacts
can present a challenge. Many loose hardware problems can be solved by simply adding a quarter
or half inch of bolt length and an equal length spacer under the head or the nut. Use hardened
flat washers at each end of the joint so that the hardware doesn't sink into the base material.
If properly torqued with sufficient bolt stretch the actual shape of the hole (within reason)
doesn't matter much since there should never be relative movement between the two pieces - if
there is the joint has failed. Anything short of a press fit of the bolt in the hole will have
some slop anyway and if the parts are moving relative to each other a little slop will turn into
lots.

Try MS21042L3 Nut The last number is the diameter in 16th of an inch 3=3/16 4= 4/16 or 1/4 5=5/16 6=6/16 or 3/8 7=7/16 so a 3/8 nut would be written like this MS21042L6
This is a fine thread nut used on Aircraft and not prone or likely to back off from vibration. They have a self locking feature there meant to be used once and only once. I agree that you should use a fine thread bolt grade 5 or better. If you use this nut and intend to torque the nut, check the running torque.The required torque to turn the nut on the bolt itself first. Then add that much more torque to the nut. I think the bushing is a fine Idea as long as the bushing is just slightly smaller than the material it goes thru length wise to allow for the clamping force needed to hold it in place.
Best of luck Byron

One year my friend and I bought identical brand new sleds together, his had one bolt in the suspension that loosened up every time we rode. None of the others ever did, nor did the same bolt on my identical sled.

Can you access this fastener to torque it, then drill it for lock wire? The motocross racers use those in some specific applications (axle nuts) that need to never loosen, but be easily removable.

I feel for you on the other issue- I had to quit riding because none of the manufacturers make a 3/4 ton sled :wink:

Nylock nuts should never be reused, also you should never use power tools to install. The friction will cause the plastic to melt, lessening its holding ability.

Is this a Polaris?

Red loctite, superglue, and glass all share a common characteristic. Shock will shatter them. Use the blue.

(quoted from post at 07:05:14 02/08/17) Is this a Polaris?

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It is an Arctic Cat F-1100 turbo. When I got it apart last night I found that there was a steel insert in the main rail hole so I have ordered new ones along with all new axles. I am looking into longer bolts. I believe that the bolts are at least five maybe already eights, and the threads are already all fine. At least they are hard enough to eat that steel insert. Hardened steel doesn't accomplish much in aluminum holes, but longer threads would. I will see how the nylocks with the star washers in new holes go for a couple rides. If they are loosening I will go to the hard steel locking ones that Bhunt suggested. I have used those before.

i think you might do well with Riv-Nuts very handy Mcmaster-Carr carries them

(quoted from post at 09:50:33 02/08/17) i think you might do well with Riv-Nuts very handy Mcmaster-Carr carries them

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Are you suggesting putting them in the holes in the axles? I have used a different brand of the same thing. It is called Nutsert, and I used them to replace nuts that were fastened to sheet metal that turned loose.