Replies

1. 
   JohnWW | Jul 10, 2007 09:08pm | #1

   Most circular saws had sealed ball bearings and they can't be lubricated.  The lightest weight circular saws might have sleeve bronze bearings, they can be lubed with a light oil like 3 in 1. 

   Worm drive saws had a gear box that uses a heavy oil, automotive differential or transmission oil is often used, or you can buy the oil from the saw's maker.

   John White, Shop Manager, Fine Woodworking Magazine 

1. 
   gdc951 | Jul 11, 2007 04:24am | #2

   The circular saw, a Porter Cable 315-1, has a fitting for lubrication.  The manual calls out a proceedure- clean the grease cup (I believe they mean the outside), remove the cap an fill it with gear lubricant, then replace the cap and tighten, which forces the lubricant into the gear chamber.  It calls for this replenishment every 50 hours.  I am a bit overdue.

   I have no idea what gear lubricant is.  P-C has a part number in the manual, but I have no idea where to get this.  My instinct tells me that this is a commodity product that P-C slaps a label on, so I would rather buy the simple verison.

   I wonder if this is the same material that I would use in the gear head on my string trimmer (which also is in need of lube).

   Any illumination on this subject is appreciated.

1. 
   EdHarrow | Jul 12, 2007 02:16am | #6

   Good grief!  That saw must be older than Dumpster Sally (7.25" wormdrive that I rescued from a dumpster).

   I don't claim any expert status, but it has been a long, long time since I've seen anything lubricated by filling a turning screw cups.

1. 
   joinerswork | Jul 12, 2007 04:24pm | #9

   Ed,

   Watch your language! Old?!!  My motorcycle has a grease cup on the distributor.  It's a totally modern bike, with cutting edge technology, like leaf spring front suspension, adjustable valve tappets, and things like a three speed hand shifted transmission, with foot clutch!  Everyone else in 1938 should be so blessed.

   Ray 

2. 
   gdc951 | Jul 11, 2007 04:31am | #3

   John,

   On re-reading your note, I would conclude that I should be using automotive differential oil in the gear lube on my saw. 

   I will give it a go.  Thanks.

    

1. 
   JohnWW | Jul 11, 2007 04:46pm | #5

   From your description of the fitting you need bearing grease.  The oil is for gear boxes that have a larger filler plug that you could pour the oil into. 

   Go to an auto supply store and get a small tub of bearing grease, it might be called wheel bearing grease, it is about the same consistency as Vaseline and is usually red in color.  The tub will have enough grease for several lifetimes.

   John W.

   Edited 7/11/2007 9:50 am ET by JohnWW

2. 
   allenb | Jul 11, 2007 05:36am | #4

   It is normally an 85/90 weight oil.  It is commonly used in differentials on automotive and heavy machinery.  Stop by the local equipment dealer he would most likely give you the amount you need if you have a small container.  Other wise you are going to end up with a quart.  Your local auto parts store should have it in stock.

    

    

   
   

   ---

   Edited 7/10/2007 10:37 pm ET by AllenB

3. 
   Cincinnati | Jul 12, 2007 05:11am | #7

   I'd recommend you phone the nearest PC service center. Gear lube is typically 75 to 150 wt oil. I would not put any kind of grease into the saw without knowing for sure that is what is required.

   Greg

   •••••••

   Exo 35:30-35

1. 
   JohnWW | Jul 12, 2007 04:06pm | #8

   What he is describing are definitely grease cups, it would be very difficult to fill them with oil and then screw them into place, the oil would run out before they were tightened down.

   John W.

1. 
   Cincinnati | Jul 12, 2007 05:16pm | #10

   John,On re-reading this thread, he does say the manual calls it a grease cup. At this point I am unsure what type of saw he has. I began using Circular saws in the 70's. I have never seen one that you lubricated except one with a worm drive. It took heavy weight oil. Gear Lubricant is a general term for oils ranging from about SAE80 to SAE150. My advice was to contact the PC service center because without knowing exactly, I could be causing damage to the saw. If screwing down the cap forces the lube into the saw, you are correct in that is consistent with a grease lubrication system. It's the "gear Lubricant" that causes a little doubt.Greg

   <!---->•••••••

   Exo 35:30-35<!---->

1. 
   RickL | Jul 12, 2007 05:40pm | #11

   I'm familiar with the saw from my days of a commercial service tech for woodworking machinery and power tools.  It is a stnadard  "grease cup" and takes standard bearing grease, not oil.

1. 
   Cincinnati | Jul 12, 2007 05:58pm | #12

   Thanks for clearing that up. Out of shear curiosity, I went to the Dewalt Service page and looked at an exploded view. They didn't show a grease cup, but they list PC p/n 801945 TUBE GREASE and p/n 801946 Lube both as item 800 in the parts list.I was unaware that PC had not used sealed bearings on a contractor's saw. Although every saw I use had sealed bearings. I'm assuming there were probably others who had similar designs.Greg••••••• Exo 35:30-35

   Edited 7/12/2007 11:00 am by Cincinnati

4. 
   gdc951 | Jul 12, 2007 06:20pm | #13

   I talked to the P-C service center.  I asked what I needed and they said that the saw needs lithium grease, comes in small tubes, get it at the hardware store.  I am all set, thanks for taking the time on this question.