Chainsaw Repair

How To Basics - Carb Fixes + Mods - IPL and Service Manuals => How To Basics and Fixes => Topic started by: aclarke on May 30, 2014, 02:24:11 pm

Title: Big taperlock
Post by: aclarke on May 30, 2014, 02:24:11 pm

Working on one of our big tree chippers today and need some suggestions.  Fan next to the cutter drum on our Morbark 2400 keeps shifting sideways! 2-15/16" shaft with a brand new taper lock fitting and key.  Tightened set screws to max and no joy, slipped again! Shaft is clean and no burrs. Gonna tack welding unless anyone has ideas??

Adam

Title: Re: Big taperlock
Post by: KilliansRedLeo on June 01, 2014, 10:47:10 am

Adan have you tried LocTite 601/603?

Title: Re: Big taperlock
Post by: brokenbudget on June 01, 2014, 11:13:01 am

I'm confused. how is it 'shifting sideways'? do you mean in/out? both shafts not staying clocked together?

Title: Re: Big taperlock
Post by: Playinwood on June 01, 2014, 12:39:31 pm

dimple the shaft with a drill bit where the set screws sit.
After that tack weld, or get 2 7/8 taper lock bearing set.

Title: Re: Big taperlock
Post by: aclarke on June 01, 2014, 11:59:58 pm

The fanwheel shifts sideways on the shaft after a few hours of hard use, key hold it from rotating. Its a brand new fan and taperlock bushing($1800) but for some reason it not creating enough pressure on the shaft to hold. Gonna try the 603 LOCTITE AND use a hammer and drift to set the inner potion of the taper rather than relying on the bolts to provide the tightening. This has been an ongoing issue with this machine, repaired twice under warranty, so i suspect this may be a design issue (taperlock too small. not enough surface area)  Pulled the drum, ill take a few pics tomorrow

Dimple and tapered set screw sounds like a good idea if the loctite doesnt work, hate to weld it.....

Title: Re: Big taperlock
Post by: Playinwood on June 02, 2014, 06:25:55 am

I hate to Loctite it also, dam near permanent. Measure your shaft.I'd bet undersized.

Title: Re: Big taperlock
Post by: 660magnum on June 02, 2014, 07:38:58 am

+1

Title: Re: Big taperlock
Post by: KilliansRedLeo on June 02, 2014, 08:13:38 am

Actually the new 603 loctite will let go if the parts are heated above 400°. Same stuff used in Dolmar 7900 saws clutch side bearing.

Title: Re: Big taperlock
Post by: aclarke on June 02, 2014, 09:24:12 am

Tim, is Dolmar using the 603 to keep the crank bearing from spinning in the case? Ive notice there wasn't much of an interference fit like other saws...

Title: Re: Big taperlock
Post by: brokenbudget on June 02, 2014, 09:36:36 am

if the shaft has spun in the past, chances are the od isn't the right size anymore. it's doesn't take much.

Title: Re: Big taperlock
Post by: 660magnum on June 02, 2014, 09:57:49 am

I have opened the gap in the taper lock in cases like this.

Title: Re: Big taperlock
Post by: aclarke on June 02, 2014, 06:03:18 pm

Pulled it all apart and cleaned/measure the shaft. About .0025 variation in some areas, found a few high spots I filed down.   Degreased with Acetone and 're installed the taperlock with Loctite 680.  Couldn't find 603 but I think the 680 is a good choice. Seated the taper then tightened set screws and repeated, hopefully it works.  I appreciate everyone's input, post a few pics tonight