Stihl 028WB Oiler Rebuild

[Wehr]

I have a late model Stihl 028 WB. It was not oiling the bar due to a worn worm gear. I have procured all the parts needed but discovered a washer that shows in the parts diagram on DIYspareparts.com. It is either part 44 (0000 958 0504 Stihl Washer) or 10 (0000 958 0406 - Stihl Washer). When I pull up a search on these parts I get a metal washer or a gasket material looking washer. I assume the gasket material is correct. Do I need this washer? Is the gasket material washer correct? If I reassemble and run without the washer, am I risking damage?

The original worm gear did not require the oiler oil seal as it was all plastic (part 12 in the diagram). The new worm gear has the metal threaded auger that drives the pump, so I purchased the oil seal gasket.

Thanks for your input.
Wehr

 

[64poncho]

Do I need this washer?

Yes, you do need the washer. It is a thrust washer for the pump drive gear. I put a new oil pump on my 028 WB awhile ago and it had the fiber washer. The metal washer was used on the plastic gear, fiber on the metal gear.

 

[Wehr]

Yes, you do need the washer. It is a thrust washer for the pump drive gear. I put a new oil pump on my 028 WB awhile ago and it had the fiber washer. The metal washer was used on the plastic gear, fiber on the metal gear.

Appreciate the input. I have the plastic pump drive gear. Assume a metal washer is appropriate.
I assume the washer goes on the oil pump housing post. Is it small enough to fit in there without removing the pump drive? Does it sit behind the pump drive?

Thanks again. I have a copy of the manual for this unit, cannot decipher which order the parts go in without having taken them out.

 

[stihltech]

The most likely issue with a non adjustable 028 oil pump is wear at the pin that goes through the metal body and into the eccentric groove on the pump gear. And play will limit the output.

 

[64poncho]

I assume the washer goes on the oil pump housing post.

Yes, washer goes on pin the gear rides on. Put it on pin before installing the drive gear.

 

[Wehr]

Appreciate the input. I have the plastic pump drive gear. Assume a metal washer is appropriate.
I assume the washer goes on the oil pump housing post. Is it small enough to fit in there without removing the pump drive? Does it sit behind the pump drive?

Thanks again. I have a copy of the manual for this unit, cannot decipher which order the parts go in without having taken them out.what are the dimensions of this order thrust washer? Doesn’t look like anything special but a plain flat washer? ID,OD? Thanks

 

[Wehr]

what are the dimensions of the thrust washer? Doesn’t look like anything special but a plain flat washer? ID,OD? I picked up a washer that is slightly loose on the pin and possibly 1mm or 2 too big. It slips under the oiler pump gear slightly but does not touch the gear.

Will the oil seal be needed? I bought one but it looks like it prevents the worm gear from seating fully and lining up with the Spur gear, the worm gear teeth sit slightly higher when the oil seal is installed.

Thanks again. So close to putting this chainsaw back into action.

 

[64poncho]

Couldn’t find the metal washer to measure but the fiber washer in my saw is a close fit to the pin and couldn’t get it out to measure. Seal is for the metal worm gear, plastic worm gear does not use a seal.

 

[Wehr]

Couldn’t find the metal washer to measure but the fiber washer in my saw is a close fit to the pin and couldn’t get it out to measure. Seal is for the metal worm gear, plastic worm gear does not use a seal.

Thank you for the response.

By metal worm gear, does that indicate the plastic worm gear with the metal auger? Versus the all plastic worm gear?

 

[64poncho]

By metal worm gear, does that indicate the plastic worm gear with the metal auger? Versus the all plastic worm gear?

Yes. The metal worm gear with the plastic drive gear.

 

[Wehr]

Yes. The metal worm gear with the plastic drive gear.

Appreciate the input.

 

[Wehr]

Couldn’t find the metal washer to measure but the fiber washer in my saw is a close fit to the pin and couldn’t get it out to measure. Seal is for the metal worm gear, plastic worm gear does not use a seal.

An M5 washer appears to be e perfect fit.

 

[Wehr]

What is the orientation of the oil seal on the oiler? Metal ring up with the flanged rubber lip down? It doesn’t fit in easily. Will it require a bump or two with an appropriately sized socket and dead blow hammer?

 

[64poncho]

Yes, metal up / out, lip down / in.You will have to tap it into the housing.

 

[Wehr]

Yes, metal up / out, lip down / in.You will have to tap it into the housing.

Thank you. I didn't want to force it without knowing.