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372 xp

Started by Hitchcock Woods, January 12, 2015, 11:50:04 AM

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Hitchcock Woods

Just replaced muffler and bracket bolts on our 2003 model 372xp.  This is the second time we've had to do this.  I put loctite on them this time.  I'm just curious if anyone else has had similar problems with the bolts vibrating out and how y'all went about fixing it.  We also replaced the muffler, gasket, and heat shield.
Chain Saws         Vehicles            LogSplitter
MS 192TC          6100D x2     TimberWolf TW3
MS 391               L2800
MS 441              HPX Gator
346XP           Honda4x4 Rancher
372XP              4x4 Frontier
HT 101 x2
MS 311

Mopar70

I fixed up an old 266se this fall, and incountered simmilar problems.
The saw was run for quite a while with a loose stud, wore all the threads out of the cylinder.
I drilled and tapped the cylinder and made a new sleeve for the inside of the muffler.
I took the same approach you did and used high strenth loctite on all the threads.
I was a little worried about the excess heat causing the loctite to fail but
Ive ran 2 tanks of gas thru the saw and havent had anything come loose.
The only down fall i can see "providing the loctite holds up" is disasembly.
you will probably have to heat some areas up with a torch to get it apart.
It doesnt look pretty but as long as it holds up im all smiles!

  

thecfarm

I might of bought mine about that same time. I only had the inside dog come loose.
Model 6020-20hp Manual Thomas bandsaw,TC40A 4wd 40 hp New Holland tractor, 450 Norse Winch, Heatmor 400 OWB,YCC 1978-79

4x4American

Common Husky problem.  Best thing to do is buy Stihl  ;D


Did you use red lock tite or blue?  The difference: red is high strength and blue is medium if you didn't know.

One thing you can try is booger the threads up a bit before you screw em in, that way they go in tight.  But don't booger up the first threads otherwise you will have hard time getting it started.
Boy, back in my day..

smh

I can't speak to the original question but do have a Locktite comment:
Six or eight years ago I bought a mixed case of Locktite thread lock. The packaging has us doing a double-take because the high strength "red" was packaged in blue tubes, the medium "blue" stuff was packaged in red tubes. Whaa? Me and my work bud were forced to redo a full day of a turbine job, thank you very much. Just so you know in case it is still packaged this way - talk about confusing.
husky 61   -   old school mods
husky 272 -   heavy metal mods
husky 4 parts-uh oh oops
stihl 180c  -   what will it be when it grows up?

sawguy21

I first tried Loctite on the Stihl 051 and 075 with mixed success. Even the red didn't keep the decom valve (075) or the muffler screws from working loose, the stuff is heat release so counter productive. I found the best solution for muffler studs was to stake them with a center punch but this is not practical for screws so I replaced these with studs where possible.
old age and treachery will always overcome youth and enthusiasm

Southside

I have had a couple of bolts come out of my 575XP, one or two muffler bolts, couple of handle bolts, but in 10 years I can't begin to guess how many hours that saw has on it.  My 660 has not spit out any bolts but has consumed two cylinders in the past two years - hard to spit bolts loose when it lives in the shop. 
Franklin buncher and skidder
JD Processor
Woodmizer LT Super 70 and LT35 sawmill, KD250 kiln, BMS 250 sharpener and setter
Riehl Edger
Woodmaster 725 and 4000 planner and moulder
Enough cows to ensure there is no spare time.
White Oak Meadows

Maine logger88

Most of my saws in that series usually start to lose bolts after being run hard for a couple years I've always just kept tightening them back up. Don't use green loctite it will never come apart I've seen that stuff bring threads with it if not heated lol
79 TJ 225 81 JD 540B Husky and Jonsered saws

weimedog

Quote from: Hitchcock Woods on January 12, 2015, 11:50:04 AM
Just replaced muffler and bracket bolts on our 2003 model 372xp.  This is the second time we've had to do this.  I put loctite on them this time.  I'm just curious if anyone else has had similar problems with the bolts vibrating out and how y'all went about fixing it.  We also replaced the muffler, gasket, and heat shield.

Not on 372's but I guess statistically it can happen with any saw. I would do exactly as you have and go with Loctite. After a month or two tighten them again. If the threaded holes in the cylinder are out of tolerance / too big, then there is always the helicoil option... and then Loctite! Did you replace the screws as well? Think I would have. On the out side chance they were made slightly under tolerance. (Threads)
Husqvarna 365sp/372xpw Blend, Jonsered 2171 51.4mm XPW build,562xp HTSS, 560 HTSS, 272XP, 61/272XP, 555, 257, 242, 238, Homelite S-XL 925, XP-1020A, Super XL (Dad's saw); Jonsered 2094, Three 920's, CS-2172, Solo 603; 3 Huztl MS660's (2 54mm and 1 56mm)

HolmenTree

The old Jonsereds I owned had the best  idea where they had a long narrow strip of metal that was the lock washer for both muffler bolts. Both ends crimped over the muffler bolt heads preventing them from loosening.
Maybe try something like that. One thing Husqvarna didn't pick up from the Jonsereds line.
Making a living with a saw since age 16.

Hitchcock Woods

Quote from: weimedog on January 13, 2015, 06:26:51 AM
Not on 372's but I guess statistically it can happen with any saw. I would do exactly as you have and go with Loctite. After a month or two tighten them again. If the threaded holes in the cylinder are out of tolerance / too big, then there is always the helicoil option... and then Loctite! Did you replace the screws as well? Think I would have. On the out side chance they were made slightly under tolerance. (Threads)

I had to replace the bolts becasue 5/6 were in the woods somehwere.
Quote from: 4x4American on January 12, 2015, 07:39:40 PM
Common Husky problem.  Best thing to do is buy Stihl  ;D


Did you use red lock tite or blue?  The difference: red is high strength and blue is medium if you didn't know.

One thing you can try is booger the threads up a bit before you screw em in, that way they go in tight.  But don't booger up the first threads otherwise you will have hard time getting it started.

We used the red Loctite.
Chain Saws         Vehicles            LogSplitter
MS 192TC          6100D x2     TimberWolf TW3
MS 391               L2800
MS 441              HPX Gator
346XP           Honda4x4 Rancher
372XP              4x4 Frontier
HT 101 x2
MS 311

HolmenTree

As Sawguy 21 said LocTite won't work . The stuff is heat released from the cylinder heat.
Making a living with a saw since age 16.

HolmenTree



As I mentioned earlier here's 1970's technology on my Jonsereds 70E that locks the muffler bolts from loosening. Easy fix for muffler loosening Husqvarnas. Some Husqvarna models would need a spacer to position the hex head bolts.



  

 

Making a living with a saw since age 16.

pineywoods

Re-tightening a screw/bolt that has come loose won't solve the problem. Replace the screw/bolt with a new one. They come loose in most cases because they stretch. Over tightening will just make it worse. This problem is quite well known where steel fasteners are used to hold aluminum parts. Example.. steel headbolts with aluminum heads, lug nuts on alloy wheels..Use new screws and do not over-tighten...
1995 Wood Mizer LT 40, Liquid cooled kawasaki,homebuilt hydraulics. Homebuilt solar dry kiln.  Woodmaster 718 planner, Kubota M4700 with homemade forks and winch, stihl  028, 029, Ms390
100k bd ft club.Charter member of The Grumpy old Men

clww

Good example pics, Willard, and a very good point by pineywoods. Over-torquing can be the worst thing you can do, leading to the original problem getting worse.
Another fix could be to use bolts with holes drilled through the head, then safety wire them together. That's what we did on the aircraft in critical areas-heat, vibration. We never used LocTite.
Many Stihl Saws-16"-60"
"Go Ask The Other Master Chief"
18-Wheeler Driver

Hitchcock Woods

Quote from: HolmenTree on January 13, 2015, 10:41:32 AM
Attention Husqvarna engineers and Husqvarna owners :laugh:

As I mentioned earlier here's 1970's technology on my Jonsereds 70E that locks the muffler bolts from loosening. Easy fix for muffler loosening Husqvarnas. Some Husqvarna models would need a spacer to position the hex head bolts.

Holmen, i might just have to fabricate something but the bolts are recessed in the muffler, but i might be able to put the metal in between the gasket and the muffler.  I guess loctite isnt the answer :-\.
Quote from: pineywoods on January 13, 2015, 11:00:17 AM
Re-tightening a screw/bolt that has come loose won't solve the problem. Replace the screw/bolt with a new one. They come loose in most cases because they stretch. Over tightening will just make it worse. This problem is quite well known where steel fasteners are used to hold aluminum parts. Example.. steel headbolts with aluminum heads, lug nuts on alloy wheels..Use new screws and do not over-tighten...
Piney, like i said earlier, 5/6 of the bolts are new.  The muffler mounts are my biggest concern.
Chain Saws         Vehicles            LogSplitter
MS 192TC          6100D x2     TimberWolf TW3
MS 391               L2800
MS 441              HPX Gator
346XP           Honda4x4 Rancher
372XP              4x4 Frontier
HT 101 x2
MS 311

Hitchcock Woods

 

 

Here is a picture of the muffler
Chain Saws         Vehicles            LogSplitter
MS 192TC          6100D x2     TimberWolf TW3
MS 391               L2800
MS 441              HPX Gator
346XP           Honda4x4 Rancher
372XP              4x4 Frontier
HT 101 x2
MS 311

HolmenTree

Hitchcock, I just took a look at my 372 too. If you could find metric hex headed bolts that size but long enough to reach from the outside of the muffler, I think 2 washers and then the metal strip under the heads would work fine.
Those 2 tubes inside the muffler would prevent the muffler from collapsing when the hex head bolts are tightened.
If I'm not mistaken metric bolts are grade 8 normally.
Making a living with a saw since age 16.

Mopar70

I like the spacer.
I didnt realize the 372 was bolt instead of stud and nut.
why wouldnt replacing the bolts with studs the same thread size but longer
Then double nut the ends of the studs??
I did that on the 266, from what i can see basically the same concept in reverse.
i used permatex brand- red high strenth threadlocker its good up to 450 F
loctite brand high strenth is good up to 550 F
I dont believe the studs or the muffler will exceed these temps but cant say for shure.

Hitchcock Woods

Quote from: HolmenTree on January 13, 2015, 12:32:39 PM
Hitchcock, I just took a look at my 372 too. If you could find metric hex headed bolts that size but long enough to reach from the outside of the muffler, I think 2 washers and then the metal strip under the heads would work fine.
Those 2 tubes inside the muffler would prevent the muffler from collapsing when the hex head bolts are tightened.
If I'm not mistaken metric bolts are grade 8 normally.
Best idea yet.  Thanks for the help Holmen!  I don't know what people did before the internet!
Chain Saws         Vehicles            LogSplitter
MS 192TC          6100D x2     TimberWolf TW3
MS 391               L2800
MS 441              HPX Gator
346XP           Honda4x4 Rancher
372XP              4x4 Frontier
HT 101 x2
MS 311

HolmenTree

Hitchcock , before you try the long bolt approach. Try a couple of Stihl torx head screw bolts, they have the serrated teeth under the heads which lock very well......probably all you need.
Making a living with a saw since age 16.

joe_indi

Loctite and lock washers will not work. What works is using self locking screws and nuts. Stihl uses tem.That  is the reason why Stihl saws have lesser chances of screws coming off from vibration. I replaced the original Allen screws on a couple of Huskies with Stihl screws and never had this issue again.
Top covers M5X25
Starter assembly M5X20 or 25
Muffler M6X25
Muffler bracket M5X16 and M5X12

HolmenTree

Thanks Joe for the #'s.
Only an experienced Stihl dealer like yourself would know those sizes and recommend them. :)
Making a living with a saw since age 16.

Mopar70

I like Holmens and joes approach alot.
you both racked my brain thinking about the pre 272 husqvarnas  "may, but not yet proven by me"  have More redundancy with the loctite approach.
Saw college never sleeps!





SawTroll

Stuff like this is very unlikely to happen if you maintain the saw as the manual says - but how many actually do that?
Information collector.

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