Plasticman

Crankshaft Pilot Bushing removal has been bantered about many times here, so I thought I would pass along the latest hot tip (as published in the June 2008 edition of Engine Builder magazine):

When removing a crankshaft pilot bushing, the easiest way is to use modeling clay or Plah-Doh. Pack the clay into the hole first by hand, and then hammer it in with a tight fitting bolt or blunt chisel. It doesn't take much force to make the bearing pop out. There is no mess, and the clay can be used over and over again.

We all got a laugh where other readers have suggested wet toilet paper rather than grease.

Note that I have not used this method, but have tried the grease method (did not work, when used with a tight fitting spare Muncie input shaft). I have the best results by using a large tap, and just tapping the bushing and then using a bolt and force it out (bottom of bolt bears on the bottom of the bushing hole, and backs the bushing out). I will have to try the clay method next time. And if you have the needle bearing pilot version, it might truly be the best way (since my tap method would not work!).


Plasticman

Olustee bus

Yeah, that grease method can be nasty. You need to wear a rainsuit and a full face helmet.

67L36Driver

5/8"-18 tpi on the last one I removed (Chebby).

Tyler Townsley

Do not use this method on every engine. 90-95 Corvette LT-5 motors have a hollow crank and a plug in the end of the crank. You will damage the plug with this method.

ref772

The 5/8" bolt trick works good on the older 2 pc. seal cranks (with the oilite bushing). The so-called 'upgrade' to the needle bearing is another story. If the needles are gone, you can sometimes get a long bolt to catch the edge of the outer race and use a heavy piece of metal as a slide hammer to pull out the bearing. A a last resort, carefully grind a small groove in the outer race with a Dremel, which will allow the race to release it's pressure on the crank hole and can then be pulled out. The best solution is NOT to use the needle bearing in the first place. The oilite bushing will last much longer than the needle bearing and will not chew up your input shaft when it does (and will) fail. I owned a clutch rebuilding business for 30 years and have seen this many times. We never recommended using the needle bearing.

AZDoug

Yes, needle bearings require use of brute force to destroy the needle bearing, then dremel and a couple grinding bits to cut thru the outer race. PITA.

Doug

buns

of pilot bushings. First the bad news. GM no longer sells their solid bronze pilot bushing that we have all loved for countless years. They only sell the needle bearing version. Now for the good news. Federal-Mogul still sells a solid bronze oilite bushing, part # PB-656 HD.

There are other pilot bushings available. Pioneer # PB-656 and SKF # B-656. The Pioneer and SKF are oilite, but not solid bronze. I spun them up on my lathe and took some hard cuts on them to generate heat, and they both oozed oil.


A simple magnet test of the 3 bushings:




P.S. None of these bushings came wrapped in oil proof paper. Apparently they did at one time, but they only release oil when heated so they probably found that it wasn't necessary.



P.S.P.S. I made a video of cutting down the bushings on the lathe. Quite interesting to see the oil being released when the bushing is heated, then immediately returns when the bushing cools. I will try and get it up on You Tube (if anyone is interested).

AZDoug

Dude....

I see from that photo that you need to get a quick change tool holder. Aloris makes one that seems to be pretty common. The BXA series is probably the right size for your lathe.

Makes changing a tool bit a 2 second swap. No more height gauge-setup-the-tool--and-adjust-the cutting-angle everytime.

Yeah, you will spend a grand for the tool post and several holders, but it makes things so much less of a hassle. I can turn, face, trepan, part, bore, groove and back bore with a simple flick of the wrist to change tools/tool holders. It is like the difference between having to get up out of your chair, walk over to the TV, turn the **** and go sit back down vs. pushing a button on the remote to change a channel.

Doug

Daffy2

I had one bush that was impossible to get out with the nasty grease method. Called my local AutoZone and borrowed a removal puller kit. Worked perfect, I think a lot of chains that have loaner tools have these kits available. All it cost me was gas back and forth.

Daffy

65ZR1

I dont even bother with the tap. A 5/8 bolt with a bit of a taper on the end will thread its way in. As for the LT5, a friend dislodged the cap in the end by driving a new bushing in too far. Didnt notice and put it all back together again. What an oil leak!!

As for the GM bearing. I just picked one up last week. Its the one we use in the LT5 but is the right one for any small block. Its bronze with the oil in it and its non magnetic. It doesnt have a smooth bore but has 3 small grooves in it. If anyone wants the part number let me know and I will find it.

buns

I will have to give that some thought, since I have way more time than money. But thanks for the input!

buns

Yes please for the part number. When I tried to buy the bronze bushing from the local GM dealer the part number came up as obsolete. He even phoned the main GM parts distribution center and they told him there are none available anywhere.

ref772

GM has obosleted the good old bronze oilite bushing, but every clutch shop in the country has them. Call Brake & CLutch Supply 254-752-4307 and ask for a PB656 pilot. I used to own the company & know they stock them.

w1ctc

Mine was really stuck. The slide hammer failed as did the grease. I finally just sliced it with a cut down hack saw blade. Took about 10 min.

65ZR1

The part number I ordered was 10125896. It has 6 groves in the bore not three like I thought. Ordered it about 2 weeks ago and it was in the next day.

chris ritchie

I've got 4 1955 to 1981 small block Chevy pilot bushings in front of me. Looks like they're all the same size. But I wasn't able to accurately measure them. Characteristics:

1. RAM Clutch # BU656: Moderately magnetic, beige in color (dark brass), sealed in plastic, doesn't appear greasy.

2. NAPA (Balkamp) #615-1161: Moderately magnetic, slightly beige, looks more like steel, packed loose in a box, not at all greasy.

3. Paragon #385: Moderately magnetic, beige in color (dark brass), packed loose in a plastic bag, not at all greasy.

4. Chevrolet (AC Delco) #10125896: Not magnetic, dark brass, packed loose in a plastic bag, doesn't appear greasy. Inside diameter is serrated.

The only one of the above that is not magnetic is the Chevy one.

The only one of the above with a serrated inside diameter is the Chevy one.

I've handled Oilite bushings. They're greasy. None of these bushings are greasy.

redred65cpe

I tried a slide hammer puller and a "screw" type puller. The slide wasn't "beefy" enough to get enough force and the jaws on the screw type puller couldn't keep a grip. So frustrated as hell, and nothing to lose, I went out and bought some Play Doh and Silly Putty as a backup. I bought a 5/8 hardwood dowl and a 5/8x5 bolt. After sanding the dowl a bit and using Play Doh, the Play Doh would still squirt past the dowl when whacking with a hammer. So, I ground down the threads somewhat so the bolt would just fit in the bushing. I put in some more Play Doh and gave it a couple whacks with my 5lb sledge. Bingo! The bushing popped out 1/4 inch. More Play Doh and another 1/4 inch or so with the next whack or two. More Play Doh, a couple more whacks and the bushing was free! No only that, when I pulled the bolt out, all the Play Doh stuck to the threads of the bolt and the crankshaft hole was pristine. I'm a believer.

larry

Plasticman

Congrats! Our first winner!

Thanks for the confirmation.

Plasticman

Plasticman

Chris,

Actually, Oilite bushings should be only packaged in a non absorbent wrap or plastic, and should feel oily (not greasy).

Grease should never be used on a true Oilite type bushing. The grease "soap" would clog the pores in the Oilite bushing, which would prevent the oil from wicking out to provide the lubricant).

If the bushing was packaged bare in a cardboard box, then the oil would be absorbed by the packaging, reducing the oil supply of the porous Oilite bushing.

Having slight magnetic properties to the bushing means that it has been pressed with iron as well as bronze. This results in a harder surface which will last longer, but will not be as forgiving to damaging the trans input shaft (if run dry after the oil as been used up). I would not have an issue with using a slightly magnetic bushing, if that is all I could find (but the pure porous bronze bushing is still the best in my view). We used the iron/bronze bushings in small appliances (as a lower cost replacement for true Oilite brand bushings), and rarely saw failures, but when failure did occur, the shaft was trash as well (which did not occur with the Oilite brand bushings - bushing would fail due to loss of oil/overheating, but once the bushing was removed, the shaft could be cleaned up and reused).

If the bushing has a strong magnetic pull, then it is mostly iron and should not be used IMHO.

The really important issue is to use a porous bushing impregnated with oil. If it is just a chunk of bearing bronze or brass, it will never last as long. If the packaging shows no signs of oil (but is a non absorbent type of packaging), some low heat from a propane torch should show oil migrating out of the pores. If it does not, then it is not what you want to use. Pilot bushings are just too hard to replace to put in a cheap piece of junk.

And don't grease an Oilite type bushing or the end of the input shaft!

Plasticman

Richard454

Autozone FREE tool loan program-a great deal-for the tool I might use a couple times a year.

Richard