Replacing bearings on a Delta DJ-20 Jointer

No doubt, I have a love/hate relationship with my Delta Jointer. It's a terrific tool, and over the years, people have expressed interest in buying it. But I love everything about this tool, and since newer versions are way more expensive, keeping it in good working order is a must. 

So when the jointer started sounding a little whiney, and the infeed table was sagging a bit, I knew it was time to schedule a tear-down. I don't know about you, but I have to get psyched up for a big repair!

My woodshop/work husband Denny and I decided to do this in two steps - first, to replace those whiney bearings, and then to address the sagging table later. 

Changing the bearings requires lowering both infeed and outfeed tables to their lowest settings, so that the entire cutterhead can be removed.  So the fence has to be rotated up and out of the way (or removed, which ever you feel like doing) 

and the blade guard removed.  

Keep track of all the parts! 

Next - remove the knives. 

When you're doing this, be careful not to leave these little height adjusters in the cutterhead;

 once you rotate the head to get to the next knife, thess parts will drop out, inside of the tool. I say this only because...I did this!  It's a PITA to find all of them.

There's a lot of dust that builds up inside those holes, so blow everything clean, too. Next disconnect your belt. Well, the belt on the machine, not your belt.

 It's probably easier to rotate the bottom pulley to get the belt off, and then push up on the belt a bit to get it off the top pulley.

 Four allen bolts hold the two bearing blocks in place. 

The bolts are different lengths, so make sure you keep track of what comes out of each piece. 

Finally, loosen the table stops (the manual calls them adjustment screws) and lower both the infeed and outfeed tables. 

With the tables both lowered, 

you can pull out the cutterhead. The bearing blocks will lift out with the cutterhead attached, and  taking the whole assembly can be a tight fit... you may have to coax it out with a pry bar. Carefully. 

Don't bend or chip anything! 

There was a ton of buildup/sawdust/crap inside, so keep your compressor and shop vac handy. 

This is what you're going to be working with... 

removing the bearings can be a challenge! It's best to support the pulley on both sides, and gently tap the cutterhead spindle out. Easier said than done, but it's possible. We used a metal punch, and damaged the shaft a bit. Try using a wooden dowel, or - better yet....

 A bearing puller helps immensely.  You can usually borrow one from a auto parts store for free.

 I walked a few doors over to my mechanic's shop and enlisted one of his guys to help me. This bearing pulled off in seconds, 

but the pulley side was stuck. Luckily, he had a few different puller attachments, and finally we found the right one to remove the pulley. 

But it took some muscle and ingenuity. And four hands.

Finally - the cutterhead with all the bearings removed - there are four bearings to replace. 

One on each side of the shaft, and one on each (inside) of the bearing block. Getting them out of the blocks wasn't that hard, but there is a clip (a snap ring) to remove, so you'll need snap ring pliers for that. 

Remove the ring,

 turn the block over and the bearing taps out pretty easily. 

 Bam, that's a lot of work just to get to these puppies!

Our one casualty? We chipped the pulley. 

 We had new bearings in no time, thanks to a bearing shop not too far from the shop. These bearings are two different sizes, so make sure you bring all the old ones with you.

We even had time for a burger run... Five Guys fries are the bomb, BTW. It was pretty easy to replace the bearings, and there are all sorts of tips for doing so. 

My best advice - if it's a tight fit, put the bearing blocks in the freezer, and heat up the bearings for 10-15 minutes on a light bulb that's turned on. Heating one, and freezing the other allows them to slip together easily. 

The shaft had a bit of wear that I was concerned about, but nothing too bad. The bearings slipped into place fairly easily. A light coat of oil to lubricate the shaft helps.  

Replace all the bearings, and here's a tip - when you replace them, always put the lettering facing out, so you can easily see what bearing you need to purchase. 

It doesn't work so well on this repair, because the numbers are all hidden.

 But when repairing something like a bandsaw wheel bearing, it's a handy thing to have access to... trust me. 

OK, so ... new bearings in place? 

Check  √

Time to reinstall everything...drop the cutterhead with the attached bearing blocks into place.

 Once it is bolted down, reattach the belt to the pulleys.

Bring the outfeed table up to where it was - the manual is pretty good about spelling this out... it takes a bit of time, but it's important to do it properly. Set that first, before doing anything with the infeed table.

The outfield table should be .012 below the cutterhead body. Use a straight edge and a feeler gauge. Once you get the outfield table set, re-install a set of sharp blades. I did a post about that here.

Finally, you can adjust your infeed table for a shallow cut, and fire the machine up. If all goes well, you should hear a nice, smooth hum of the motor.  

Nice job!

 We were still having some table problems... which I'll address in the next post - how to adjust your co-planar tables when they won't adjust anymore!

Stay tuned....