I copy alot of stuff from here to dorkiphus, now here's one from dorkiphus to here
Here's a quick and dirty how-to for building a replica of the Porsche factory tool for removing the bearing dust caps on the front of a 911.
The inspiration for this came from helping Matt DeMaria of Stuttgart Performance Engineering tech my car for a DE one weekend. Matt said my front bearings were loose, and told me to remove the dust cover and tighten them up. So I asked him "You got a big ol' chisel I can use ta take the dust cap off?". Matt looked at me like I was insane, and then proceeded to explain to me that pounding the dust cap off with a chisel like a ham fisted gorilla eggs out the hub, which is made of aluminum. Do it too much, the dust cap won't seat anymore and you have to buy new hubs. "Fair enough. So how do you remove them?" I asked. "With this - the factory tool made specifically for this job" he said. (BTW, this is how Matt does everything - the right way, with the right tool. Its pretty impressive to watch him work on stuff, IMO).
Turns out, the the factory tool is a pretty simple contraption - a metal cap with 3 set screws attached to a slide hammer. The cap goes over the dust cap, and the set screws are tighened into the groove around the cap. One good whack with the hammer and you're done - cap off with no side load to egg out the hub. Here's a picture:
Click to view attachmentAnyone who knows me knows I'm a tool junkie, so I wanted one of these (since I do a lot of bearing adjusting). Matt told me that he remembers the puller running about $100 20 years ago .
Looking at it, I figured I could build a replica for less. One trip to Home Depot later, I had about $5 worth of parts and was ready to go.
Step 1. Get your materials. Here's what you need:
(1) 2" cast iron pipe cap.
(3) #10-24 x 1" Thumbscrews
(1) #10-24 tap and drill bit set
(1) Bolt (M6 x 25mm in my case) to attach the tool to your slide hammer
(1) Slide hammer. Mine is a $10, 10lb POS from Harbor Freight. One of the best $10 I've ever spent on a tool.
Click to view attachmentThis is the key to the whole tool - the 2" cast iron pipe cap. $3 at Home Depot, IIRC.
Click to view attachmentStep 2. Drill a hole in the center of the top of the pipe cap for the slide hammer mounting bolt.
Click to view attachmentStep 3. Mark around the edges of the cap at 120 degree angles. You can see the template I used in the picture above. This doesn't need to be super precise, obviously.
Step 4. Center punch at the 120 degree marks 8.5mm (0.330") from the edge of the cap. Drill with a #25 drill bit.
Click to view attachmentStep 5. Tap the holes with the #10-24 tap. I bought a cheap drill and tap set from Home Depot for #10-24, came with the right drill bit for the tap. Remember to use a lubricant when tapping the hole (always a good idea ). This cap is cast iron, which is soft and taps very easily.
Click to view attachmentMmmm... threads...
Click to view attachmentStep 6. With all three holes along the edge drilled and tapped, install the thumbscrews and the slide hammer attachment screw.
Click to view attachmentHere's a shot from the bottom, showing how the thumbscrews will grab into the dust cap groove:
Click to view attachmentStep 7. Attach to the slide hammer...
Click to view attachmentAnd you're done! Total time to build, about 30mins.
Now to use, put the tool over the dust cap and tighten the thumbscrews into the groove:
One good whack and presto: