How do you guys tell if their is too much play in a rod or wristpin bearing?In a saw with just normal wear are those bearings usally ok for one top end reringing.??thanks Frank C.
If you know there is play because you can feel it- thats too much. Try to find a manual/service book with the specs on it and then buy a plastic gauge. If you are going to do a ring job, my thinking is that you might as well put beraings on as well, and then its been done.
With the rod at the top of its stroke, there should be no play up and down. A little side to side should be acceptable though. The wrist pin, put it through the rod, try to move the ends, sort of a twisting motion, if you feel it move it's too much. Plasticgauge is a good idea, though I've not used it on a saw motor. Good luck with your saw. :) TT
Reason I'am asking fixed a log splitter for a tree service guy I know he gave me a husky 394xp hard starting felt like low comp.Pulled it apart jug and piston look real good ,rings worn.I'am probibly the first to pull it apart,going to put crank seals just in case she was sucking wind.Chainsaws have anti friction [needle] bearings plastigauge worthless.Was just wondering how the saw guys check,all will have endplay crank and pin.Their must be a way to check you really can't measure.I may be wrong on this but always thought if not abused the lower end is good for at least one rering job.Thanks for your help.Frank C.
changing the rings, but not changing the crank bearing, is like dropping the tranny in a vehicle and not changing the clutch.
might as well change the bearing while youve got it all torn apart. could save yourself a headache down the road
Do you mean the piston pin bearing, or the actual ball bearings on the crank? Thanks.
It's a chainsaw, not an Indy race car. Crank bearings can't be changed without removing the crank, which involves splitting the case. WAAAAY overboard for a simple ring job. If you want to swap out the bearing for the wrist pin, fine. If not, that's probably fine as well.
Or you can leave it in a box for 5 years while you convince yourself that you'll make it 'perfect' one day. ;) :D
Those big Huskys are pretty durable and should run just fine for many years even if the tolerances aren't perfect like brand new. If it just needs rings then throw some rings in it and run it! 8)
My genral rule is a bit of radial play is normal. Any lateral play in the direction of the rod throw and it gets replaced.
Captain
Lots of saws [Husky included] are made so that the rod/crank/bearings are one piece, they don't come apart. The wristpin bearing, yes, but not the rest.
Thanks guys,when I change the crank seals I'll check the main bearings I'am sure their fine .Probibly replace the piston ,pin and pin bearing with the rings,rebuild the carb.and start hauling out chips.Have a 24" bar for it I like a powerfull saw all my cutting is horizontal no limbing.Most of my firewood is from butts and crotches at a stump dump.Frank C.
A saw will run a long time before it gives up the ghost . I've resurrected a few that were pretty sick cats and they keep on cutting away . A set of rings and seals prolongs the life of most of them ,cheap fix .
Hi Frank,
There are two bearings on the connecting rod, top and bottom or big and small end. To replace the bearing at the small or top end, remove the circlips and tap out the pin. Support the piston by using a block of wood or if you buy a Baileys plastic ring compressor usually the support piece is included. Once the pin is out the bearing pushes through. If the pin is snug, use a little heat.
The bearing at the large or bottom end is pressed in on the pin. The cost of replacing the bottom end bearing is usually more expensive, if you can find the bearing, than just replacing the crank. I judge the bottom end by how much up or down play it has. .015 or more at the bottom end and its only a matter of time until your going to need a new crank. A real small amount of up and down is ok, and Im sure you will be able to tell if its bad once you try to move it. Look around the case and around the bottom of the jug for tapping marks which will tell you right away. Side to side movement is required to allow the crank bearings to seat so all pin style cranks allow the connecting rod to move left and right. If this is a work saw, I replace the top bearing when doing the rings. Maybe $12-15.
The crank bearings on the outer case races also wear. To replace them, in most cases, your going to have to split the case. Some of the designs use a bolt in engine block called a clamshell design, and on those you would use a bearing puller. I find that the bearings will come off or out easier when heated. Some of the workshop manuals advise to put the crank in the freezer and the bearings in the oven upon reassembly. If you dont have a heat gun, try a 150 watt spotlight bulb about an inch from where your working and let it warm for 15-20 minutes.
If you replace the small end piston pin bearing, pay attention to where the piston pin clip ends are located, and keep the ends up and down in line with the connecting rod at the top of its travel.
To give you an idea on splitting the case here is a video with a neat tool;
http://www.youtube.com/watch?v=2G-vapNwntw
Best wishes,
Bob
Bob,thanks for the video,did you make that spiffy puller?It looks as though the puller is designed to catch the outer race of the ball bearing and push the crank out.What I've done before is warm the outer case around the bearing ,if necessary,and tap on the end of the crank with a soft hammer,I like the puller better.Is it better for the crank bearings to stay in the case or come out with the crank?or whatever they decide.Oh what if any sealer do you put on the case gasket to hold it in place? Thanks so much Frank C.
That tool was made for a member on another forum that goes by canadiancarguy. He said he paid around $300CDN to have it made. It looks to be identical to the Husky tool, which you can get from the dealer for around $68. The tool does grab the outer race of the bearing, pushing the crank out. This leaves the bearings in the case, you just heat the case and press them out. You should be able to read the part number of the tool in the picture. This is the Husky tool that does the 394, as well as most other Husky saws. Part # 502 51 61 01
(https://forestryforum.com/gallery/albums/userpics/14240/dsc01599.jpg)
That is a spiffy tool and certainly works well. Looks like overkill for chainsaws though.
Thanks again that won't be a hard tool to build,looks to be 1 1/2 square tube arms flush with the outside.Probibly two bars mounted on a base and an arbor press could be used if you have clearance for the case.This forum is valuable must be at least 1000 years of experiance here.Frank C.
Hi!
About sealer for the gasket. Normally I don't use any, but with a thin gasket I could use some grease to hold it in the right place when putting the crankcase together. Nothing fancy, just the same, as used for the bearing for the clutch-drum.
Good luck with the job ahead.
Sab.
I don't have any Husky saws so I am not familiar with the bottom end. Sthil saws have usually 3 locator pins. I use those for holding the case gasket in place while the two halves are being mated back together.
That is a neat tool for splitting a case. Very similar to the way I was thinking of making one. Actually a little more simplier in design than what I had in mind.
My preference is to see the bearings come out with the crank. This is just me though as I get paranoid splitting cases . I am so afraid of damaging the case halves in some way if I had to get a bearing out on it's own. Putting them in is not really a problem. But still get paranoid. Splitting a case is not all that easy and is alot of work. Screw it up and your out alot of time and and possible a saw.
Larry
This tool takes all the apprehension out of it.
Cool, 8)
Yesterday,after seeing the picture Dave posted of the case splitter puller ,went out to the shop and made one.It works just as slick as Sharkies vidio,in fact I'am so impressed I may smooth it up and paint it.The square tube is 1 1/2", 6" long made the arms out of 1/4 steel plate.To use it you must take the piston off the rod.It helps if you have a saw with the jug off,I made a cardboard template,then cut the two arms with a torch.Used a 5/8" long nut welded between the legs with a 6" piece of threaded rod pointed at one end outher "T" handle.Take note of the relationship of the screw point and the arms with the nub.It took me about an hour,your mileage may very,I don't move at warp speed.
Splitting the cases is really not that big of a deal .It is however a bit intimidating the first time you do it .
The Stihl company sells the tools to do it but other methods work just as well .
Hey Bandmiller, would you mind posting a pic of the crankcase splitter you made?? I'm going to make one as I have a bearing job to do on a 045 super I just picked up for parts. The thing was seized so I put some mix in the jug and let it sit. I got her freed up, fixed the recoil and pulled her over a few times, started getting smoother. I put the plug back in and voilla, decent comp!! I flipped the switch and she fired and ran instanly!! I', like wow to good to be true! So I figure I'd do a comp check next, pulled the plug and pulled her over a few times. Thats when I heard the horrible grinding noise in the lower end,... bummer. But anyways I figured heck I'll do my first main bearing job and maybe get a decent running 045 Super for short coin. Anyways I got to tear her down and split the cases, just getting myself mentally prepared first,.. lol! Thanks
Rockfarmer,I got a chuckle when I saw you are from Ashburnham guess you know rocks.Dave Shepard already posted a pic mine is a carbon copy of his.I hope its not the lower rod bearing thats the problem as the assembly is pressed togather.When I pulled the husky 394 apart the main bearings were ok but noisy when spun.They were just a common ball bearing 203 if I remember right had some in my desk drawer.The basic dimensions of the puller are 6"X6" with 1 1/2 inch between the legs,which can be bent slightly to fit different saws good luck neighbor.Frank C.
Hey Bandmiller, yes we have a lot of rocks!! They just keep on coming out of the ground, a real rockfarm! Yes I got you on the case pusher, I started making one last night. I should have it welded in a couple days when I can get back to it. Went to the Stihl dealer today for parts,.. sol, nothing. guess I'm using e-bay,... He laughed at me when I asked for 045 super parts, I guess he thought that was real funny. He said that real milling guys buy 1800$ saws, ya I guess I'm not a real miller then, ha, lol!