Chainsaw Repair
How To Basics - Carb Fixes + Mods - IPL and Service Manuals => How To Basics and Fixes => Topic started by: KilliansRedLeo on May 04, 2014, 10:25:37 am
-
Don't forget that when installing crank bearings in a 372 the flywheel side bearing goes ALL THE WAY TO THE BOTTOM OF THE BEARING CUP! The clutch side bearing cup is only as deep as the bearing however the flywheel side is deeper than the bearing to accommodate the shoulder on the crankshaft. When you pull the case apart it does not look that way because sometimes the bearing will move when splitting the cases. The bearings (according to HVA) should be installed in the case halves NOT on the crankshaft. If you install on the shaft you run the risk of damaging the bearing cup or worse yet breaking the case half when putting the case back together because you are forcing the bearing to the bottom of the cup.
The crankshaft is pulled through the inner race of the bearing using a special tool obtainable from Husqvarna. The tool when used correctly will pull the crank through the inner race of the bearing with no heat needed and puts no side thrust on the bearings when done. Make sure you check your 372 Workshop Manual for the correct tool part number, as HVA makes this tool for several different series saws and they are not interchangeable between series!
You begin by pulling the crank into the clutch side of the case then follow up with the flywheel side. The positioning dowels go in the clutch side to help align the gasket.
This same process is also applicable to the Jonsered equivalent models.
-
I have a few modified deep sockets that work just as good as the husky tool. ;)
-
So do I! Sometimes I can't see spending the $$$ on the tool for one saw! I have read many posts on another site where they put the bearings on the crank instead of in the case. Just can't understand why they would read how to do it in the WM and still do it wrong and then swear by their method. Oh well, you buy them books and buy them books and all they do is eat the teacher.
-
I've never put bearings on the crank on any saw to install. Never understood why one would either. Maybe I am missing something. ???
-
In my opinion you are not missing anything. Some folks learn to do it wrong and continue to do it that way because they were taught or were told to do it wrong. Then they explain that they always do it that way and have never had a problem. Well, OK you are a very lucky person but you are still doing it wrong. You do not force steel into cast non-ferrous metal no matter who said or taught you what.
OEMs spend lots of money training and creating the WMs, if there wasn't good reason for their methods and procedures, why would they expend the millions to do it in the first place.
-
they 'never had a problem' due t the fact the owner was probably so pissed at the bottom end only lasting a tank he decided to throw the saw or go somewhere else :) and the grease monkey just never heard back from them.
-
Here is a quote from a guy on another forum who 'never had a problem' doing it wrong!
?????? stopped by, and I broke his 372xp's pto crankcase half trying to force a bearing home. First time I have broken a case half and it had to be someone else's. Fortunately ?????? had a good used one so I did not have to pay alot to replace the part.... I got frustrated and hit the socket on the bearing face hard enough to break the sealing face outside.....
Dang it!!!!
Buy em books and buy em books and all they do is eat the teacher. Perhaps this fellow should take the money he did not have to pay for the case he ruined and buy the correct tool and get a copy of the WM!
-
This is how your cases should look after using Oven (200C 20-30 minutes) and the freezer (bearings in there for 24 hours prior to install) to install new bearings. Bearings should drop right to the bottom of the bearing cup with no force necessary.
First picture is the clutch side.
Second and third pictures are the flywheel side showing the bearing at the proper position at the bottom of the bearing cup.
-
I heat the case halves with a small torch. The bearing will go in by hand most of the time. I have put them in the freezer for a little while and just opened the box and put them in. Never really noticed much difference in them either way.
-
+1
-
Great bearing info KRL. I suppose Im one of the guys who learned to do this service wrong by putting the bearings onto the crank first. To double check, I just re-read my cs-8000 service manual and that is how they said to do the service for that model of Echo. Same thing in the Deere 800v service manual. I suppose the saving grace is I always heat the cases before trying to drive anything.
-
Sharkey, you are following the manufacturers procedures which is correct. The whole point of this is to show how Husqvarna recommends this be done on a 371/72 saw. There are saws in the HVA line that HVA recommends the bearings on the crank.