Cleaned and greased four angle grinders today

[ndnchf]

After reading about the need to grease these, I decided to go through mine. It was a pretty easy job, and now I feel better about using them. They were an old craftsman, an old Dewalt 402 and two harbor freight grinders. All had grease in them, but in all cases, the gears were bone dry. The grease had been slung off into the housing. Grease in the old Craftsman was like dried peanut butter. It was still OK in the others. But all were cleaned out and new red grease was slathered over the gears and into the case, then reassembled. I also blew the dust and dirt out of the motors. They all run nice and smooth now.

Lesson learned - do this once a year. It's easy and will help them last.

 

[SuperCat]

Do new angle grinders need to be greased? I have read some posts on GJ that some ratchets are dry out of the box, maybe this happens to angle grinders too?

 

[ndnchf]

One of mine I just bought. There was grease inside, but almost none on the gears themselves. I would grease new ones too.

 

[PoorOwner]

The first time you push the trigger it will just fling out of the gears again...
I'm all for equipment maintenance. I am not sure you can tell any difference or "smoother" than before on an angle grinder.

 

[SuperCat]

Thanks for the quick reply. It would not have occurred to me to grease a new angle grinder, but I just (finally) bought a decent one (Makita 9557PBX1 kit, $80 from Amazon) and read your post today. I hate to take it apart, because it is brand new, but now I gotta see for myself if it has grease in it. Thanks again.

 

[JohnDeere1]

I have the Makita with paddle switch it never occured to me to grease it or if it had grease it runs nice and smooth but I got it used in a snap on tool bag full of usa sk,snap on and matco tools for $50 guy said he was quitting the buissnes, I'll open mine up tomorrow I doubt the guy took care of it.

 

[jumbojak]

The first time you push the trigger it will just fling out of the gears again...
I'm all for equipment maintenance. I am not sure you can tell any difference or "smoother" than before on an angle grinder.

Exactly. Aside from a thin film you aren't going to have much grease on the gears of an angle grinder if you use it. Maybe if you run one really, really hard the grease might heat up enough to find its way beck but as soon as you cut it on, zip! It'll be back off again.

 

[sberry]

Check the brushes on the 402. It will ruin them if they go too long.

 

[pepi]

The grease won't stay on the gears for a year, probably not even a day.

YUP !! after the first use....

 

[cjarvis]

Here's a product that's made for the job: http://https://www.lubriplate.com/Lubriplate/files/90/903854e7-2cf1-4ba2-ad41-9a93fe76947f.pdf however I'd rather see it in a NLGI 0 or 00.

 

[Wamsutta]

The grease always gets flung off and deposited on the interior of the gear case housing - leaving the gears dry. I'm tempted to try worm drive lube next time.

 

[ndnchf]

I agree that the grease gets slung right off as soon as you turn it on. So it must be the thin film that remains that protects the gears. Of the four I took apart, one was about. 6 or 7 years old, another was probably 20+. None had any noticable wear on the gears. One had a little wear in the bronze bushing on the back of the gear that it's shaft runs in. I put a drop of oil on these bushings before reassembly.

 

[Fretters]

Oil tends to separate from grease when it's warm, and the grease softens and creeps. There'll always be thin film of lube whilst ever the grease is good.

 

[mbshop]

I take everything with grease apart. Most times there is very little grease to speak of. I just glob it in and go from there. It's amazing how they are trying to save on grease. Everytime I do this the unit runs quieter. You may get a little leakage if run hot but thats what a rag is for if you do not use high temp grease. Older units will have hard useless grease every time. On other stuff I take it apart and oil things up. Once took a look
at a roller bearing and there was nothing in it so check those also. I use a syringe to lube those.
if you use your grinder or tool a lot then service it more often. As to flinging, if you have enough grease in there it will find its way to the gears. I checked on mine.

 

[Ign]

So before we go reinventing the angle grinder, who here has actually worn out the ring and pinion on an angle grinder?

This. "Smoother" is from quality bearings and components properly balanced- which isn't necessarily actual balancing but just greater QC, tighter tolerances on the rotating assy, etc

 

[Shootinok]

I think it's a good idea!
I took two apart today and greased em up. One dewalt had old hard ugly stuff in it.
Thanks for the idea.
I can't see any reason NOT to maintain them as easy as it is to do.
The one thing I was left thinking when I was done is .... why do I only have two grinders?

Thanks a lot NDN ! (Mr. 4 grinders)

 

[Provincial]

I use #00 grease in some gearboxes. It will leak if the unit is not well-sealed, so it is slightly fluid at room temperature. It should have less drag on the moving parts than #2 grease if the gears don't get very warm. #0 grease would be even more fluid.

Changing grease regularly in a tool used daily is good maintainance. Lubrication and checking brushes are the two most important actions to address wear parts on a grinder. The bearings are almost always sealed, so all you can do is check them for damage/wear when you change the grease.

 

[metaldad]

i have added grease to all my grinders.
mobil nlgi2