PC 7424xp

[Kevin845]

Does anyone know if it needs to be greased regularly or any other routine maintenance that needs to be performed?

[VISITOR]

usually the only thing that needs to be replaced are the brushes and that's even after hundreds of hours (if not more) of use...

[MarkD51]

Does anyone know if it needs to be greased regularly or any other routine maintenance that needs to be performed?

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.

[Kevin845]

Your thoughts are exactly inline with my thoughts. So may take it apart now that winter is approaching in MA. Thank you for sharing, much appreciated!

[MarkD51]

I would like to add though, the old verbage, "That if it ain't broke, don't fix it".

That if you are the original owner since new, and that the machine appears to be operating fine, no unusual things to note from past use and memory, then I'd say not to tear the machine apart. Not unless you think such is warranted, and that you possibly have many hundreds of hours of use on it.

If you've only maybe done a 1/2 dozen vehicles with it, it should still be fine I would think.

While the PC certainly isn't a swiss watch that will fly apart in a 100 pieces when opening the machine up, still, a person, possibly due to inexperience with the machine and its assembly could possibly do more harm than good.

I definitely felt there was an issue with my Griots DA, (and I was correct) and while I could've simply sent it back for free replacement, the shipping costs to them would've been on my dime.

[dlc95]

I have two 1st gen 7424 machines that I absolutely love. One is from 2007, and the other 2006. They were both new old stock that I picked up last year. One of them runs smooth, cool, and quiet. The other is a little rough. I plan on repacking the grease on the noisier one. It also gets really hot at the spindle. I bought some 3M 20206 (I think) 5" back plates to help mitigate the heat.

A 7424xp does the bulk of my work, and in six years hasn't had any issues.

[Crispy]

My Porter Cable runs as good as the day I first used it.

If it ain't broke I'm not going to fix it.

My 3" Girots Mini though is another story.

Seems to vibrate a lot and gets super hot very quickly when using speed 6.

I'm hesitant to take it apart because of the "life time wartanty" but if replacing the brushes and lubing the gears would fix it, then maybe worth the risk.

Shipping from Canada is expensive, so my risk is a little higher.

Does anyone have a blow up drawing of the internals of the Girots Mini or the Rupes equivalent?

[VISITOR]

My Porter Cable runs as good as the day I first used it.

If it ain't broke I'm not going to fix it.

i have the G100 which is a pc7424 re-badged with a lifetime warranty. i really don't use it, it's a rattle box and since using the GG6 (also has a lifetime warranty and better in every way), the G100 has been collecting dust...

[dlc95]

i have the G100 which is a pc7424 re-badged with a lifetime warranty. i really don't use it, it's a rattle box and since using the GG6 (also has a lifetime warranty and better in every way), the G100 has been collecting dust...

I still need to try one of those.

[VISITOR]

I still need to try one of those.

use a GG6 once and you won't go back to using the PC/XP...

[PaulMys]

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.

Merit? Hell, now this is one of the best posts I've ever read.

Excellent post, Mark!! I do the same thing with every power tool I buy and think "hey, this thing shouldn't run like this......"

Apart it comes, and I have certainly found similar results as yours on more than one tool.

I like the way you think, bud. :)

[MarkD51]

Merit? Hell, now this is one of the best posts I've ever read.

Excellent post, Mark!! I do the same thing with every power tool I buy and think "hey, this thing shouldn't run like this......"

Apart it comes, and I have certainly found similar results as yours on more than one tool.

I like the way you think, bud. :)

Well, I did take a different path than what most people would've done with a machine that was thought to be bad, and had an issue.

That 3" Baby Griots DA I did not buy from Griots, AG, or any other authorized dealer, but from a seller on Ebay for the small sum of $63. But it was a brand spanking new machine, one could definitely tell it had never been used prior to my acquisition.

I doubt I had more than an hour's use on this machine prior to opening it up to inspect.

But none the less, I did contact Griots Garage after the repair, posed the questions of return and what their policies were, and they told me that it didn't matter where it was purchased, or no bill of sale, that they would accept the return, and replace the machine free of charge.
Now that's what I call a great company!

Also as well, when a unit of whatever brand is within its warrantee period, and perhaps even after that warrantee has expired, and was purchased from AutoGeek-Autopia, the Unit hypothetically failed not due to user error-damage, one might be wisest, and I would advise-suggest first contacting these people first before any further actions are taken, and/or executing a self repair.

I'd suspect there are accounts-stories of Autogeek as well going beyond their commitments, and replacing a machine that failed, and perhaps too even past the manufacturer's warrantee, in that they want their customers happy and satisfied.

Had my machine that failed or thought to work strangely been a Rupes, or a Flex purchased from AG, costing multiple times what the baby Griots DA cost, I'd surely be contacting AG first before trying to initiate repairs myself.

[MarkD51]

The major problem I recall with my 3" Griots DA was a Brush Set that is simply retained by slotted depressions on either case half.

But when installing the new set of Motor Brushes into one half of the Plastic Housing Case, and getting ready to re-assemble the two Case Halves it was easily recognized that due to the spring pressure on the Brushes, they had a quite easy propensity to not stay put in their assigned small depression slots.

With some thought, I then simply used two small strips of Electrical Tape to better secure-retain them in the one housing half, so that they would not lift out as the case halves were re-joined together.

This did the trick!

After complete re-assembly, I then finally manually rotated-turned the motor via the Backing Plate by hand to "run in" and initially seat the Brushes for a few minute's time before electricity was applied to test.

[dlc95]

Mark, have you ever removed the plastic head cover from a 1st gen PC 7424?

[MarkD51]

Mark, have you ever removed the plastic head cover from a 1st gen PC 7424?

Gee, no I haven't. But I have remembered some threads about the PC, perhaps it was the newer PC7424XP DA, in that without using a Stick Handle, or if choosing not to use a handle at all as some do, that some, (perhaps it was Mike Phillips himself) stated that one should secure the Plastic Head Cover with Bolts-Washers, that this front Plastic Cover can pop off. Thus is appears it then clips on.

Never having owned an earlier 7424 machine, I am not sure they are identical in design? I would maybe guess yes, but again not sure. On either machine, they may just simply clip on?

With that said, it is likely that one would maybe need something like a small Jeweler's Screwdriver to gently and carefully pry the Front Case from the Machine, and guessing this part probably has to come off first before further disassembly can commence.

With a little diligent online searching, you may be able to find an exploded view of the PC7424, or possibly even a youtube vid, and this may aid you.

Hope this helps.