Help me understand how oil gets to the chain on a McCulloch Timber Bear

jmartin919 · Jul 12, 2023

So I got the manual and automatic oilers to "work" on this saw but it seems more oil ends up on the bottom of the saw then onto the bar. It looks to me like oil comes out the small orifice in the case (picture #1) and fills a chamber that is created by the case, inside and outside metal shields, the upper vertical slot in the bar (picture #3) and a cavity in the outer housing with the chain brake. Once it fills up this chamber it flows up the slot in the bar to an opening in the top of the bar where it gets picked up by the chain and is distributed around the bar. So I'm guessing the problem is this chamber is very leaky since it's made up of these ridged pieces sandwiched together. Do I have this right? Do I not have the right bar(it's an Oregon)? Seems like it would work better (be less leaky) if the outer shield completely covered the upper slot in the bar to make a smaller chamber with less pieces to leak. Why have the horizontal slots in the outer shield if the oil is intended to go up into the opening in the track of the bar? And it seems like the opening in the track of the bar is very susceptible to blockage.

heimannm · Jul 12, 2023

I don't think that is the correct bar for the D-176 mount as I can see an additional oil passage in your photos. Check to make sure the groove is cut all the way into the bar adjuster slot so the oil can pass to the groove in the bar. And make sure if the groove is cut deep enough to reach the adjuster slot that it is not blocked with sawdust.

You can see on these bar there is no separate oiler hole.

Mark

drumbum · Jul 12, 2023

I think the bar is a d176 as they come today.

the 276 didn't have the extreeee hole

thenne1713 · Jul 13, 2023

The two holes in the bar are the oiler, one used at a time, the 2nd used when bar is flipped. The inner/ outer shield should be removed, cleaned well to shiny and they will seal much better. The BRAKE/COVER is the Outer SEAL for the slot. The oil pump only engages when clutch engaged at higher speed and pump disengaged when at idle. Bad plastic gear= no oiler/ no oil. Good Luck.

heimannm · Jul 13, 2023

On the McCulloch 600 Series saws and their 10 Series saw that use the D-276/D-176 mount the oil passes from the "unused" (top) bar adjust hole/slot directly into the groove provided the groove is cut deep enough to open into the bar adjust hole. The oiler outlet is not intended to align with the small oil passage hole in the bar.

The automatic oiler is pulse operated off crankcase pressure differential and operates all the time the engine is running, but the flow is significantly increased when the engine RPM comes up.

There is a manual oiler as well to prime the automatic pump and to provide extra oil as may be needed when cutting dirty wood or trees with high resin/pitch content.

Mark

jmartin919 · Jul 13, 2023

Thanks, guys. Yes, the top oval opening that would be used by the adjuster if the bar was flipped over is cut deep enough to reach the top bar groove and oil does come out there after I cleared it out (seems like a poor design to me since it would be susceptible to filling with dust fairly easily compared to the hole on the side of the bar). But the chamber is basically open all the way to and including the chain brake housing making the chamber unnecessarily large and prone to leaking between the various pieces sandwiched together.. Oregon specifies this bar for this saw based on the part number on it. Anyway, my solution was to apply two layers of HVAC foil tape over the oval opening in the bar, thereby greatly reducing the size of the chamber and opportunities for leakage. Works great!