Harvester head saw unit

[Mike_M]

Has anyone rebuilt or replaced their saw units on your harvester heads? Have been using our TJ 762 the last couple weeks and it is working pretty well. It has an auto chain tensioning system on it but I find it difficult to put chains on the head. I thought maybe the chains were too short, so I tried a little longer chain(not a lot)and it threw the chain fairly quickly. I can't think of anything I'm doing wrong, but maybe I am. We have considered going through the head next winter to repair/replace and tighten everything back up and thought about replacing the saw unit. Or at least rebuilding it. I looked at the Hultdins saw units, but have no idea on cost. Anyone ever replace or rebuild the saw on your harvester heads?

[MT logger]

is the bleeder plugged?

[Mike_M]

No, I loosen the screw that takes the pressure off and it bleeds out a bit of fluid. And I am able to push the bar back about an 1 inch or 1 1/4". Its possible I'm not use to the auto tension. Our Waratah head is tightened manually, but at least it gave me plenty of room to adjust to get the chain over the tip of the bar.

[MT logger]

could be an obstruction inside bar mount also might need new O-rings its been a long time since I had one.

[bushmechanic]

That's the way all the ones we have had work also, we have two screwdrivers with the 7 mm wrench for changing the chain. We put a phillips screwdriver in the hole of the bar to aid in pushing the bar back then we use a flat screwdriver to assist in putting the chain around the bar nose sprocket. We currently have a 745 head on a 1070 Timberjack and that has the Supercut system on it .... still using the screwdrivers!

[Mike_M]

That's exactly what I have been doing, but thought someone would think I was an idiot for using a flathead on the sprocket nose. I feel better knowing I'm not the only one. Sounds like that's the way it is. Do you still like the auto-tension vs manual tightening? It sounds from what I've read on the Oregon web-site the auto-tension is better. Thanks for the information.

[1270d]

Does it have a hultdins supercut saw?

[Mike_M]

I don't believe it is a Hultdins supercut, but will double check.

[Mike_M]

Just talked to a gentleman at Hultdins about my saw head. He provided some real good information and said it sounded like I could have sawdust packed in the bar mount. It is common for this area to build up saw dust and then not allow the bar to move its full throw making it difficult when putting chains on.

[bushmechanic]

 I don't think it's a sawdust related problem, as I said before we have had several 762 heads, B and C series all were like it. Now were using a 745 with the Huldins Supercut 100 all the same and a new chain is the hardest to install. I like the auto tensioning but when the piston gets worn you won't be able to keep o-rings on it. We got a new one the other day and now they have two o-rings on it so it must have been an issue.

[1270d]

If it is a supercut, take the bar mount right off.  There's is three places sawdust and grime build up.   The two slots where the keeper bolts ride, and a groove on the other side from the keepers.  There is a little half moon on the bar carrier that fits into a notch when the chain is all the way slack.   

Also, get the double oring pistons bushmechanic mentioned.   They save a lot of hassle.

Also be careful not to put too much torque on the keeper bolts.   They break very easily