Stihl 028AV - Not Oiling?

[SteveSr]

Hello,

I just scored this saw off of Craigs List. It runs and appears to have good compression so I bought it. It supposedly has an oil pump / bar oiling problem. Can anyone provide suggestions on where to look for this problem before I start tearing everything apart?

Thanks,

Steve

 

[singletrack100]

Others with much more diagnosis experience wll chime in shortly, however, what size bar was the supposed oiling problem ocurring with, and have you tried running the power head without the bar, revved up, to see if it pumps oil?

Duane

 

[SteveSr]

Others with much more diagnosis experience will chime in shortly, however, what size bar was the supposed oiling problem occurring with, and have you tried running the power head without the bar, revved up, to see if it pumps oil?

Duane

The bar is 18" .325. I took the oil baffle / guide plate off and there was no evidence of oil coming out. I also looked in the tank and it was pretty close to empty. So the next step is to put oil in the tank and see what happens. I can't do it tonight - The neighbors might get upset!

 

[jackjcc]

The oiling gears are plastic and can strip out. Taking off the sprocket cover will show the gears.

 

[Big_Wood]

you need to remove the clutch cover backing plate to get at the oiler. the gear that attaches to the oiler worm gear is almost always what strips out on these saws. it's definitely not the first 028 with oiler problems and it definitely won't be the last.

 

[SteveSr]

you need to remove the clutch cover backing plate to get at the oiler. the gear that attaches to the oiler worm gear is almost always what strips out on these saws. it's definitely not the first 028 with oiler problems and it definitely won't be the last.

Great call! I pulled the clutch cover off and found the drive gears intact and bar oil all over everything! The pump drive gear spins freely in BOTH directions but the pump plunger doesn't move. If I lift up on the drive gear (about 1/4") I can see the pump piston move slightly.

Next question is how to get the drive gear off and remove the pump. According to the repair manual the pump gear is supposed to unscrew clockwise (Left hand thread) but it doesn't tell you how to keep the shaft from turning! Any suggestions or is the pump just broke?

Once I get the pump out is it rebuildable or should I just look for a used/new replacement?

Thanks,

Steve

 

[Gypo Logger]

Haven't seen to many oiler problems. Sometimes a chain can have too many drive links thus the oil hole in the bar no longer mates with the oil outlet in the casing.

 

[SteveSr]

Haven't seen to many oiler problems. Sometimes a chain can have too many drive links thus the oil hole in the bar no longer mates with the oil outlet in the casing.

Good point. The spur sprocket was thoroughly trashed which may have allowed the bar too far forward. Unfortunately this doesn't explain my other findings above.

 

[Big_Wood]

the pump gear does come off clockwise. just spin the clutch drum counterclockwise while lightly pulling up on the gear attached to the pump worm gear. it'll pop right out. the leak is probably coming from around the worm gear. i hate those saws oilers. most times they just need to be taken apart and cleaned up but the worm gear may be so worn or stripped that it can't grab the pump worm anymore. last one i worked on had a worm that looked good but it was worn enough to not grab. parts are NLA so you gotta go the the swap meet or ebay. switch it over to a rim sprocket if it hasn't been already.

 

[rednecksawman]

I seen this before on some 028 oilers the gasket behind the oiler leaking snd oil comes out from behind the pump especialy if its been pulled off and is torn if you replace the gaskit be sure to clean up the old gaskit real good and use some gaskit sealer on the crankcase side when you mount the oiler back just enough to cover the gaskit and not plug the holes

 

[SteveSr]

the pump gear does come off clockwise. just spin the clutch drum counterclockwise while lightly pulling up on the gear attached to the pump worm gear. it'll pop right out. the leak is probably coming from around the worm gear. i hate those saws oilers. most times they just need to be taken apart and cleaned up but the worm gear may be so worn or stripped that it can't grab the pump worm anymore. last one i worked on had a worm that looked good but it was worn enough to not grab. parts are NLA so you gotta go the the swap meet or ebay. switch it over to a rim sprocket if it hasn't been already.

Thanks, Got the worm/drive gear off. That weird unidirectional seal was preventing the gear from just pulling up. Got the pump off and no obvious leak from behind the pump at the gasket. Didn't really see any oil coming out the plastic cover end of the pump either. My only thought is that it is coming from around the seal on the drive gear as you mentioned. I cleaned the pump body with carb cleaner which I think swelled the seal a bit. Don't know how long it will last.

I also noticed that the plastic end cap was fall-off loose. Also the eccentric drive pin was also fall-off loose are they supposed to be that way?

I am planning on converting it to a rim sprocket. Does this effect the oil pump at all? or the plastic clutch dust cover?

 

[texastele]

The rim sprocket does not affect the oil pump. The cover doesn't affect it either. You might pull the clutch drum off and look at it. There is a finger from the worm gear that is supposed to fit in a cut in it. The drum shouldn't fit right if everything is not together right, but it can. The finger can also wear and no longer interface with the drum. If you are not getting the interface the oil pump doesnt get driven. Also, you might replace the oilpickup body. It can get clogged with sawdust or if the oil sits for so long it can get clumpy and plug up the body.

 

[SteveSr]

The rim sprocket does not affect the oil pump. The cover doesn't affect it either. You might pull the clutch drum off and look at it. There is a finger from the worm gear that is supposed to fit in a cut in it. The drum shouldn't fit right if everything is not together right, but it can. The finger can also wear and no longer interface with the drum. If you are not getting the interface the oil pump doesnt get driven. Also, you might replace the oilpickup body. It can get clogged with sawdust or if the oil sits for so long it can get clumpy and plug up the body.

Are we talking about the same saw? The 028 that I have has the Stihl Rube Goldberg external gear drive oiler and not the much improved clutch rim drive as in the 026/260.

Yes, I am planning on flushing the pickup line before it all goes back together. I would really hate to have to replace that pickup and hose. It would make putting the pulse line back on look like child's play!

 

[texastele]

My apologies.

 

[Wood Doctor]

Haven't seen to many oiler problems. Sometimes a chain can have too many drive links thus the oil hole in the bar no longer mates with the oil outlet in the casing.

The oil outlet in the casing is usually more than long enough to reach the bar's oil hole, regardless of chain length. That's why the outlet is a long slot. The vertical alignment of the slot with the bar's oil hole is a far more common problem, but I have yet to see this problem with an o28--only with a 290 after the owner outfitted it with a 3/8" pitch bar.

Strangely enough, the same bar lined up perfectly with the oiler slot on a 310 that was made about two years later.

 

[SteveSr]

I have recently seen pictures of the strainer that goes in the oil pickup tube. It looks like the holes in the strainer are much larger than the transfer holes in the oil pump itself. Does crud ever back up at the oil pump inlet?

What should I do about the loose nylon pump end cover? Attempt to glue it in place? with what?

 

[coldfrigman]

Stupid question, but oil should NOT be coming out of the center of the plastic tooth worm gear oiler sprocket, right??? I noticed a small pin size hole in it on the outside???

 

[peak-industry]

learning...