Some advice needed MS460 crank play

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DiggerDirect

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May 4, 2018
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Hello all, this is my first post here having just joined recently. I did a search first, but didn't come up with an answer.
My ms460 quit oiling a couple days ago, so I opened her up to have a look. Plastic worm gear threads were shot, clip was bent and Oil pump pretty much froze up. (I bought this saw new back in fall of 2001, a spur of the moment had to have it thing after I 'treed' my trusty 044 in the middle of a logging job, and our local dealer didn't have any more in stock) and it has been an amazing, never a problem, reliable 'friend' for near 17 years.
Anyhow, my question. After removing gear & pump I notice there is a little bit of sideways play in the crankshaft if I take hold of it and wiggle side to side. Not much, but there is some. With everything assembled it's tight no movement. I'm thinking this might not be normal and I should be replacing the crankshaft bearing(s) as well? I didn't notice any vibration or other symptoms leading up to the no oil but thinking perhaps the play caused the pump/gear to fail? I'm no stranger to wrenching, having an old ford 850 tractor for a 'skidder', an older manual (man powered) sawmill & a jeep cj5 as my daily driver keeps the tools shined up pretty well, its just I've never had to work on this saw (or my 044 before it) other than normal maintenance, wear parts & occasional carb rebuild. After reading a boat load of 046/460 posts here I was thinking I should get some opinions first, maybe that slight play with everything removed is normal.. Any info appreciated!
460_oilPump6x8.jpg
 
If you grab the end of the crank and wiggle, does anything move or make noise? If so... that’s a sign of problem. Any play is bad... play at the crank could mean bearings, crankshaft itself, or bearing recess in the case.

I’ve rebuilt a few 1128s with bad bearings. Use the oil pump as a stop on the clutch side when installing the pto side bearing. Lots of threads on the process here and elsewhere.
 
Any crank bearing play in a two stroke means the bearing needs to be replaced. Replace both sides and both seals, and replace the small end bearing while you have it open. Check the big end bearing for play. If it's got too much you'll need to replace the crank. Measure the piston, cylinder and rings and replace any that are out of spec or approaching it. Do it once and do it right and you'll get another 17 years out of it.
 
It’s bearing time. You’ll have to split the case to do that.

The PTO side is proprietary to Stihl, and as mentioned above, will need the oil pump attached for a depth stop. The Flywheel side is a regular 6202 with the correct speed rating. The set from Stihl is usually around $25-30.

You’ll need an oem gasket kit with seals, around $25 for the kit. I wouldn’t mess with aftermarket stuff. Unless you have the dedicated tools for seal install, take some pics and measurements now of the seal’s depth on both sides. Installing incorrectly can cause an early failure and they aren’t avaiable individually, you’ll have to buy another gasket set.

If you don’t have the tools required to do the repairs, many people here that will do the job for you for a lot less than your dealer will charge.

Oh, and don’t lose this O ring.

D70CB39B-B50B-4440-A4E4-C957EC61C172.jpeg
 
Thank you all for the replies & information. I'll likely be doing the repair/rebuild myself at some point in the not to distant future, right now I'm still in the data gathering, reading & understanding phase. I figure to replace whatever saw needs (or soon will need) while I have it broke down. One other question if I may, I have 165 +/- lbs compression (checked several times with two different gauges), piston looks good, this should be fine? The old 044 will become primary again for a time, with mainly medium size white pine saw logs, a few hemlocks & some around the mill work in the forecast it won't mind. :)
 
If you don’t have a case Splitter, just punch out the 2 pins to the Flywheel side. Remove all the case bolts-it helps to reference the new case gasket as a reference for location.

Then bake that sucker at 325* for 30 min. I use a large toaster/powder coating oven, but some aluminum foil on the grill or in the oven when the wife slips out works great.

Then take out with some welding gloves and wack the crank with a nylon or brass hammer. The entire thing will literally fall apart.

The bearings typically stay on the crank with this method, so you’ll need a bearing puller or a 2 jaw standard puller to get them off.
 
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