UPDATE torebuild/replace?

[Wild Turkey]

UPDATE:  Tore down two of them.  Bearings were good and smooth but the rubber cups that held the back of the armature in place (part of the "double insulated" engineering 
 ) was soft and causing vibration.  Ereplacements has them for $2.60
  Also discovered the grease in the gearbox was badly hardened so I'll add some 90 wt and put them back to work.



I have three Porter-Cable 7336 6" ROS that I picked up cheap years ago.  They've been my "go to" sander for years but have begun to vibrate a bunch so I figure bearings are shot.

ereplacements has sets for about $60/ set.

New sanders are about $140

I'm arguing with my cheap self that between parts cost, labor, frustration, hidden problems and not knowing what will go next it may be time to replace.

At least one of them


Anyone been there, done that?

[wpwoodworker]

I have three Porter-Cable 7336 6" ROS that I picked up cheap years ago.  They've been my "go to" sander for years but have begun to vibrate a bunch so I figure bearings are shot.

ereplacements has sets for about $60/ set.

New sanders are about $140

I'm arguing with my cheap self that between parts cost, labor, frustration, hidden problems and not knowing what will go next it may be time to replace.

At least one of them


Anyone been there, done that?

I faced similar dilemma. I went to local bearing supplier and got replacement bearings for about $12 per machine. The only bearing needing replacement was on the oscillator/eccentric. The motor bearings were fine. Took less than hour to clean out the accumulated gunk and replace the bearings.
The sanders run like new even after several years use.

[KC]

I have three Porter-Cable 7336 6" ROS that I picked up cheap years ago.  They've been my "go to" sander for years but have begun to vibrate a bunch so I figure bearings are shot.

ereplacements has sets for about $60/ set.

New sanders are about $140

I'm arguing with my cheap self that between parts cost, labor, frustration, hidden problems and not knowing what will go next it may be time to replace.

At least one of them


Anyone been there, done that?

I dunno how long 'years ago' is, but I'd be willing to bet the ones you have now are better made than new.

[Bob Vaughan]

The only bearing needing replacement was on the oscillator/eccentric. The motor bearings were fine.

This is typical on most hand held vibrating sanders, random orbit or regular.
That little bearing takes a lot of guff compared to the motor bearings.

A possibility to keep in mind is that when a bearing gets noisy and close to failure, the aluminum bearing socket (housing) can wallow.  A new bearing will just slap around in its housing.  If the bearing pulls out easily, then the socket is likely worn. 
A solution to this is either replace the surrounding parts or use JB Weld.  I've found that JB Weld works great.  Clean the socket.  I like lacquer thinner for that.  Get out some paste wax and put it on the bearing.  That assumes the bearing is already on the shaft.  Buff the wax off slightly so there are no gobs.  Mix up a dab of JB Weld and smear it around inside the bearing socket where the bearing's outer perimeter seats.  Assemble and wait 24 hours for the epoxy to fully cure (even though it sets rather quickly).  Keep the surface where the epoxy was mixed so you can test it for rigidity.

This process also works for router bearings and other portable power tools that have an aluminum bearing housing.

Portable power tools with plastic bearing housings that have a worn bearing socket require the part to be replaced or the tool replaced with a better one.

[museumguy]

I'm a cheap guy myself, I'd repair the sanders. As stated, the older ones are better than anything you get nowadays.

[Wild Turkey]

Okay -- I'll tear down the worst one and head for local bearing supply

[Cabinet Monkey]

Sell em for parts and buy a good sander. 

https://www.amazon.com/Bosch-Power-Tools...B07WK42NC5


What the heck are you doing that you’ve worn out three sanders ?

[Stwood_]

Okay -- I'll tear down the worst one and head for local bearing supply

There ya go.

[Cabinet Monkey]

Glad you “fixed” em.

I’d still suggest giving a “good” sander a tryout to see what you’re missing. Less vibration, faster cutting , and  dust collection.  The Bosch has a 30day no questions return period lie Festool, so there’s not much to lose.

[Wild Turkey]

I'll keep that in mind, but $30 now will take care of my sanding needs for a while. 

If I ever get into a project that needs more sanding than I can do with those I'll look them over.

But I hate sanding