Needle Bearing Removal Q's

Joe, I used to have a similar problem with brass bushings in pumps, the bushings would be at the bottom of a blind hole. We used to put about

1/2" of oil(or grease) in the hole and use a piece of round stock that fil ID of the bushing. After filling the hole and inserting the round stock we would hit the round stock with a hammer, driving the oil to the bottom of the hole, which would cause the bushing to lift a little. It usually took 4 or 5 attempts and the bushing would lift enought that we could use a modified gear puller to remove the bushing. I don't know if this would work for you, but it might be worth a try.

Greg

That's a great technique I've used many times, but it doesn't work for needle bearings, unless they have an inner race (rare) and are sealed. The grease just comes right out (in your face) between the rollers. One possibilible variation might be to turn a punch to the correct diameter to fit the ID. Then relieve the diameter from the business end to double the thickness of the target bearing. Fit a sleeve of some sort of plastic or silicone that can conform to the needle bearings enough to seal it. For the larger bearings, you might even be able to use a tube with an oversleeve to seal the OD to the needle bearing. Fit a plunger to the ID and use that to pump the grease. Beyond that, the only thing I know of is a slidehammer.

Don't know if it's useful to this discussion, but I have seen equipment with dowels and sealed bearings in blind holes, that have a drilled port to the backside of the recess. That port is threaded for a grease zerk for extraction purposes.

Agreed. Great technique and idea... But ours look sorta like this:

What I had in mind was a reverse puller "thing" that spreads out inside the needle bearing with "hooks" under it somehow... But no such animal exists that I'm aware of.

They exist but you do have to look for them. I've got a larger version of what you need in the shop.

I'll try to explain with text though this where a picture is worth a thousand words.

Start with a piece of round stock the size of the hole you're going into (actually it could be larger and just turned down to that size on the end). Turn a "hook" on the end by going undersized a little before the end. Drill a hole through it lengthwise for a the expander. Slit the hook end in 2 or 4 segments. Make a tapered expander bolt to go in the hole of the first. When tightened the taper will force the hooks out to get a grip.

For the pulling part you've got several options. Either attach it to a slide hammer or thread the outside and using a nut, washer, and piece of pipe to do the pulling. More sophisticated is to use a hollow ram porta power cylinder for the pulling (shouldn't be needed here).

If the above doesn't get the idea across I'll try to get some pics so that you can understand.

Wayne Cook Shamrock, TX

I think snap-on actually sells those bearing extractors like that, for getting in behind blind races or bearings. But for a one-off like this, a home-made on works pretty well, I've done this.

The step should have a square edge if there's a bit of room behind the bearing to hook in - if it's *really* blind then you have to rely on the chamfer on the bearing OD to give some purchase, in which case a pointy, 45 degree per side, edge seems to work best.

Jim

Over in the CNC group, someone posted a part number which led me to this:

If I can find one that goes a bit smaller, I'm all set! ...And so the search continues.

Regards, Joe Agro, Jr. (800) 871-5022 (908) 542-0244 Automatic / Pneumatic Drills:

Spindle Drills: V8013-R

What's this. Are you trying to sully this groups operating principle of "It's better make a tool than buy one even if it cost's 10 times as much."

:-)

Wayne Cook Shamrock, TX

If you have any room behind the bearing you might be able to use a pilot bearing puller with a slide hammmer.

If the aluminum housings are free of the rest of the assembly you can pour boiling water over the housing and the bearings will pretty much fall out. You might have to tap the housing a bit but it works reliably.

Cheers,

Kelley

Sorta. I'm not as strong of a subscriber to the idea of false economy as some are. :):)

Oh, sorry... :-) :-)

That is the trick I use when changing the pilot bearing while doing a clutch job.

It works good!

Try going to Motion industries or some other bearing house and they should be able to sell you a puller.

Joe, You may be able to turn a shaft to "just fit" down inside the bearings, but then turn down that diameter a bit more but leave a ridge on the very end. Split the shaft on the end, bore it out from the backside and make sort of an expanding mandrel with a ridge on the very end which will "hook" onto the case of the bearing. You could even get "fancy" and make the ring sharpened on the outside diameter so it would wedge itself between the bottom of the hole and the "frame" of the bearing. HTH Ken.

Start with a "Dyna Bolt" or similar brand concrete anchor bolt. These are available in a range of sizes that will suit the inside diameters you mentioned, so select one that will just fit inside your bearing. I'm assuming that the bearings are to be removed as they are worn out so you don't need to re-use the original bearings. This can also work on bushes or ball bearings.

Drop the bolt down the hole and tighten just enough to catch the bearing below the edge and pull out the bolt. If you want to get fancy you could turn a groove on the bolt's expanding case so it catches the end of the bearing easier. You may need to use a selection of washers or pipe off-cuts to suit the outside diameter or shape of your housings.

Once the partly expanded bolt has a catch on the bearing, a slide hammer, or a lever can be used to apply the removing force. One lever I have used was a

3 foot length of steel pipe with an oversize hole drilled through it about 6 inches from the end and this was under the nut. You could find a small block of wood to protect the aluminium housing from marking.

The cost of the concrete bolts is far lower than the replacement bearings and can be considered as expendable, but can often be re-used for concrete application later.

Hope this helps, Peter

Rex B wrote in news: snipped-for-privacy@corp.supernews.com:

Packing with grease will work on needle bearings, not in one shot, but it does work.

Find the closest fitting shaft, biggest hammer you can comfortably swing, and thickest grease you have. Use a good cloth shop towel around the hand holding the shaft, as the grease will shoot out at very dangerous velocity, you dont want to get your eyes or anything tender near there. It may take a dozen or more times of repacking the grease just for one hit, but it will come out eventually.

The more of the hole you can seal the better, but as long as you cant bottom out the driver too easily, it will transfer energy into the bearing.

Same principle, but you really need a fresh zerk fitting and coupler on the grease gun or the leakage will kill you. Most of the bearings/bushings I drive out with this method are larger then my grease gun piston.

Jeff