Originally Posted by
MarkD51
In the few years I've been here, and reading pretty much all that has been written about the PC7424XP, I cannot recall reading anything about such.
But that doesn't mean your questions and thoughts aren't valid ones that do not hold some serious consideration.
I've never popped open my own PC D/A, but one day may. But I have once popped open my Baby Griots 3" D/A the second time out, of what I felt was some more additional noise, and rough running from the first time I used it.
And yep, what I found, was two Motor Brushes cracked in half, and was lucky that it came with an additional spare pair of brushes. It looked like they may have been damaged upon installation at the factory, that they came partially out when closing and buttoning up the two main housing halves.
But to get onto what else I noticed upon opening the unit, was a Pinion Gear Drive Set that was as dry as a bone, with a lot of grease just slung out of the way of the Gears. No doubt caused by centrifugal force and heat, and while there was plenty of grease inside the case, it appeared none of it was doing the gears any good as far as protection, and perhaps as well the noise levels of operation when running.
I entirely removed all of the factory grease, questioning its quality, as this was an unknown, and replaced this lubricating grease with a like amount of full synthetic Permatex Super Lube Grease fortified with PTFE.
(in truth, the factory grease may have possibly had similar qualities to Super Lube, but like I said, this was an uncertainty)
The machine worked much better, seen the somewhat design flaw of how the brushes could pop out while re-assembling, and addressed that issue. The machine then ran smooth, and suspect the major issue was the cracked brushes. The re-lube certainly didn't hurt.
I would suspect the Porter Cable D/A has a similar basic construction inside like the Griots in regards to the Gear Set Design and mechanics of operation.
Thus with all this being said, and if a person feels they have both the mechanical, and electrical expertise to open up the Porter Cable machine to inspect, and to possibly check things like lubricants, and possibly re-lube, I myself see no harm, and in fact may help the machine operate more smoothly, run cooler due to greases being where they should be, and by inspection, possibly finding other assembly snafus which could head off premature failure.
I would think too, that like the Griots 3" DA, the PC DA may also eventually "fling" it's protecting lubricants around inside the case, and again the gears would be getting little to none of the lubricant's protection benefits.
I also think that with such machines, it is also not wise to leave such machines to bake away in really hot garages, or sheds during summer months, that heat may cause lubricants to soften, and then move away from the gears possibly.
Hope my ideas have some merit.