Screws keep loosening up.

[Andrew15]

Hello,Andrew here with a little problem.

So on my Husqvarna 120 mark 2 the screws that keep the bumper spikes in place just won't stay tight.They keep loosening and the spikes become useless not giving me any grip at all.Any ideas on how i could fix this problem?

 

[ammoaddict]

Are the screw holes damaged?

 

[Andrew15]

Are the screw holes damaged?

Since the screws don't stay tight i asume they are

 

[Colonel428]

Loctite is good for helping to keep those screws from backing out on you. Just make sure it's the type that says "removable" on the package.

 

[ammoaddict]

Since the screws don't stay tight i asume they are

Cut a small zip tie in two pieces the length of the screws and put a piece in each hole, then put the screws and tighten them up.

 

[WheelHorseFan]

Old AMF Harley owner/ Mechanic knows what to do!..lol My cousins a Harley mech...

Loc-tite the screws threads, "let it cure" (read bottle for time), install with split lock washer & torque to spec.

Washer then nut if you use nut, just slide on bolt first if no nut used.
Red Loctite for Permanent/Max hold
Blue Loctite for Temp hold.

 

[dboyd351]

yep
blue loctite should do it

 

[muddy42]

If blue locktite doesn't hold the screws, the holds are probably stripped.

I have recently successfully performed a helicoil thread repair. The helicoil set comes with a specific size of drill and tap and then these coils that you thread in to act as the new thread. You get 5.2mm kits designed for 5mm bolt etc. The problem is that helicoils are designed for 'through' holes rather than the 'blind' holes common on chainsaws. To get round this you need to fabricate a straight tap, to use after the tapered tap to remove the material at the base of the hole. I made a straight tap from a 5mm bolt with a slit down the middle to remove the swarf. I then levered apart the slit to achieve the required 5.2mm size.

 

[ammoaddict]

OP says this is Husqvarna 120. That would be roll thread screws into plastic crankcase. Locktite ain't gonna help with the damaged plastic threads.

 

[muddy42]

OP says this is Husqvarna 120. That would be roll thread screws into plastic crankcase. Locktite ain't gonna help with the damaged plastic threads.

Ah OK, what about epoxy as a more permanent solution? You can still helicoil into plastic, although I've not done this.

 

[ammoaddict]

Ah OK, what about epoxy as a more permanent solution? You can still helicoil into plastic, although I've not done this.

Epoxy or helicoil may work, I've haven't tried either in plastic. I have used zip ties in several plastic intake manifolds on Husqvarna 50 series saws. They hold very well, quick and easy fix and pretty much free.

 

[muddy42]

Epoxy or helicoil may work, I've haven't tried either in plastic. I have used zip ties in several plastic intake manifolds on Husqvarna 50 series saws. They hold very well, quick and easy fix and pretty much free.

Nice one, I will remember that trick.

 

[Andrew15]

Cut a small zip tie in two pieces the length of the screws and put a piece in each hole, then put the screws and tighten them up.

Idk man,i was just thinking to put some silicone in the holes,then screw the screws in and just let the silicone cool and hope it will hold.But i will try your idea first.

 

[ammoaddict]

Idk man,i was just thinking to put some silicone in the holes,then screw the screws in and just let the silicone cool and hope it will hold.But i will try your idea first.

Silicone won't hold. You would have to have some kind of epoxy or resin if the holes are badly damaged. I have used zip ties more than once and they will hold if not completely stripped out. It would hurt to try it. Let us know how it does.

 

[dboyd351]

I agree. Silicone will not hold. Try the zip ties. If that doesn't work try epoxy or jb weld.

 

[Wow]

Silicone won't hold. You would have to have some kind of epoxy or resin if the holes are badly damaged. I have used zip ties more than once and they will hold if not completely stripped out. It would hurt to try it. Let us know how it does.

IF the screws will get Hot, I've used small clean copper wire. Usually Stranded no insulation. Even on the motor bolts on my 23 hp Lawn mower motor bolts. In metal some screws like to have a groove cut length wise half way up the bolt. I use a Dremel tool for that. It kinda makes it into a self tapping screw or bolt. I've also used a combo of the two. I've grooved a bolt, put stranded copper wire in the hole and torqued it down. For plastic where it's not going to get hot.. The plastic tie wraps work great. Good luck.

 

[cookies]

Can you source screws from another saw that screw into plastic that have higher raised threads so it cuts into fresh plastic when screwed in? even if they are too long you can cut them down and put lock tite on them, use the red version so it bonds stronger. If you have a friend that works at a body shop ask them to help you with providing some 3m tpo plastic parts repair (70 bucks for 350ml) and you pay for a replacement mixing nozzle...that stuff is the cats meow for permanent plastic repairs ..inject it into the holes and immediately screw the screws in but not fully tight, let sit 5 minutes and remove the screw and remove excess immediately, 1 hour wait and you can fully tighten them down and use blue lock tite and sand off any excess. If choosing to use a epoxy I would suggest getting and using bob smith brand quick cure, its got a nice and thick consistency yet should be able to drip it into the hole using a bamboo skewer, fully hardens in 10 minutes after it cools.

 

[Abbeville TSI]

I remember when we sold Husqvarna saws, there were brass inserts available that threaded into a drilled out stripped screw hole. You then used the OEM screw in the bushing. The inserts came from Husqvarna. Kind of like a helicoil for plastic...

 

[94 wrangler]

For what it's worth. I have a very good friend that retired from WVU as a Forestry Prof after many years instructing. A lot of his teachings were in the forests of WV. I have been a Stihl guy for over 50 years and he would always give me the BS over saw manufacturers. He said the college once bought Stihl saws back in the day. Then for a reason unknown to me, the college went with Husqvarna. Two years prior to his retirement, the college went back to STIHL! One reason or rather a major complaint that he mentioned to me was their "Husky's" developed loose screws and the overall quality just wasn't near the same as it once was.

 

[piglosi]

Idk man,i was just thinking to put some silicone in the holes,then screw the screws in and just let the silicone cool and hope it will hold.But i will try your idea first.

A trick my father showed me that worked for with outboard motors was to cut a few pieces of solder and place in the hole then tighten the fastener. The soft solder will bind up the thread as it fills space. Just a hack thought that pulled me out of a jam and worked.