Pilot Bushing Installation

Nervous about using a hammer on my new crate engine. What's the best way to install a pilot bushing in the end of the crankshaft? The 1961 shop manual actually says "drive" into the crankshaft and the special tool is nothing more than a driver that gets whacked by a hammer. Don't want to overdo it though. I did put the bushing in the freezer; still couldn't get it without whacking it harder than I'm comfortable with. Also, is there anything wrong with putting a slight chamfer on on the outside edge going into the crank to keep it from getting hung up starting?

Thanks!
Brad
 
great questions!

yes you generally check dimensions on the crank recess and outer bearing carefully first then use a drive tool and oil the bearing , and seat it with a couple good whacks on the tool,there should be a .001-.003 interference fit, pack the bearing in DRY ICE for 30 minutes, before installing it and use some graphite lube powder on its outer surface before driving it into place and it usually goes in easily.

Pilot bushing clearance to trans input shaft should be .001 to .004
...with .002-.003 being considered about ideal,and the common brass pilot bearing
brasspilot.jpg

should be greased on install, but manufacturers parts vary and .005-.006 clearance to account for a bit of bell housing miss alignment and heat expansion is common.

to remove a pilot bearing you pack grease thru the center hole until the grease is flush with the bearings upper surface and insert a dowel into the center hole thats a loose sliding fit but will slide into the bearings inner diam. a good hard whack, on the dowel will hydraulically force the bearing out as the grease expands under the bearing, as the dowel compresses the grease as the grease can,t be compressed, and the hydraulic pressure forces the bearing up and out of the crank.
crank pilot bushings are usually removed with grease, being packed into the recess inside and behind the bearing, and having the bearing hydraulically forced out by driving in a wood or aluminum dowel to compress the grease, the grease forced to move away from the dowel, forcing the bearing out
2124.jpg

http://www.autobarn.net/lis55500.html
THE PILOT TOOL CAN BE USED WITH GREASE AND A MALLET TO REMOVE THE OLD WORN BEARING, AS IT FITS EXACTLY



pilotbearingtool.jpg

THERE ARE TOOLS TO REMOVE PILOT BEARINGS BUT THE HYDRAULIC GREASE METHOD WORKS IF YOU DON,T HAVE ONE

a bearing or seal driver , with interchangeable spacer rings ,that matches the outside diam. of the pilot bearing is usually used, to drive the new bearing into placebut IVE seen guys use a SOCKET and a hammer successfully
http://www.harborfreight.com/cpi/ctaf/d ... mber=35555
35555.gif

http://www.harborfreight.com/cpi/ctaf/d ... mber=95853
95853.gif


http://www.dormanproducts.com/p-11019-690-014.aspx
bronzepilota.JPG

bronzepilot.JPG

BTW its been my experience that a properly installed and lubed sintered bronze pilot bearing works better and lasts longer than the roller bearing designs, and once the recess in the cranks clean, simply packing the bronze bearing in dry ice for 30 minutes then quickly moving it with pliers and placing it in the recess and a good smack with a plastic hammer seats it easily
http://www.lislecorp.com/divisions/prod ... roduct=351
55600
Clutch Pilot Bushing Remover
Uses Hydraulic Pressure to Remove Brass and Bronze Bushings.

Screw the self-tapping tip 2-3 threads into the brass or bronze bushing. Then pump out the bushing with a grease gun. Fits brass or bronze bushings from 1/2" to 3/4" I.D. Not for use on steel bearings. Made of case hardened steel.

ok first ID point out that not all cranks are finish machined to accept a pilot bushing for a manual transmission, so its time to get out your digital calipers and check both the inside crank mounting hole diam. and the outside of the pilot bushing diam.
there are ROLLER PILOT BEARINGS, but they have a mixed reputation for durability
http://www.summitracing.com/parts/SUM-G1700/
sum-g1700_m.jpg

and
SINTERED BRONZE PILOT BEARINGS
http://www.summitracing.com/parts/RAM-BU656/
ram-bu656_w_m.jpg

pbear1.jpg

lak-15977_w.jpg

now Id also point out that theres different inner pilot bearing diameters available because not all transmission spline are configured the same..bronze bushings were the standard for decades,rather than needle bearings for the transmission input shaft. Tolerances were pretty loose on this older stuff and no one disputes that the bronze bushing , if correctly installed and greased,worked fine.
you can bevel the bronze style bearings to ease installation,BUT NOT the ROLLER STYLE for what should be rather obvious reasons

the three reasons for needle bearing failure (the "new" information) seem to be 1) damaged during bearing installation, 2) damaged during transmission installation, probably due to a failure to meet contemporary bell housing run-out specs, and 3) materials incompatibility with older transmissions. Apparently modern needle bearings are bad ju-ju with 1960's transmissions regardless of tolerances. So, knowing the failure modes and avoiding them, it's probably not very risky to use a needle bearing.
image_14671a.jpg

http://www.harborfreight.com/blind-hole ... 95987.html

some related info here

http://forum.grumpysperformance.com/viewtopic.php?f=71&t=447&hilit=+pilot

http://chevellestuff.net/qd/crank/crank.htm

http://www.chevyhiperformance.com/t...rain/0707ch_main_bearing_clearance/index.html

viewtopic.php?f=71&t=584&p=757&hilit=+bellhousing#p757
 
Last edited by a moderator:
Great, thanks.

1) I think I'll try heating the crank a bit with a paint stripper heat gun, but not too hot.

2) still anxious about whacking the crankshaft even with the driver tool. Wouldn't that risk damaging the bearings?

3) got another idea, turns out that a harmonic balancer removal tool with 7/16-20 bolts will also fit the flywheel end of the crankshaft. I could use that to press the bushing in rather than hammer it in. Sounds low risk enough or am I missing something?

4) Another dumb question: The face of my bell housing is out of alignment (not the hole) by .004, the spec is .002. What do I use for good shims. I could take apart my feeler gauge but I hate to do that.

5) Your opinion on reusing ARP flywheel bolts? I've heard some people say that by design, when you torque them, they undergo plastic deformation and if you reuse them and retorque them again that additional plastic deformation significantly reduces the yield strength. Could just be BS though. Maybe they don't plastically deform.

Brad
 
brad.arcova said:
Great, thanks.

1) I think I'll try heating the crank a bit with a paint stripper heat gun, but not too hot.

probably won,t hurt,as long as you use a heat check like an IR temp gun to keep temps under about 250F, but I use DRY ICE on the pilot bearings to get the same effects
viewtopic.php?f=4&t=1337&p=2921&hilit=+infrared#p2921

2) still anxious about whacking the crankshaft even with the driver tool. Wouldn't that risk damaging the bearings?

in theory you might but if you use the dry ice it usually seats in two or three whacks

3) got another idea, turns out that a harmonic balancer removal tool with 7/16-20 bolts will also fit the flywheel end of the crankshaft. I could use that to press the bushing in rather than hammer it in. Sounds low risk enough or am I missing something?
never tried,that route . if it works so much the better, let me know if it works

4) Another dumb question: The face of my bell housing is out of alignment (not the hole) by .004, the spec is .002. What do I use for good shims. I could take apart my feeler gauge but I hate to do that.

summits sells , off set bell housing alignment pins that work,
read this two thread links, I posted


http://www.summitracing.com/parts/LAK-15907/


viewtopic.php?f=71&t=584&p=757&hilit=+bellhousing#p757

http://www.circletrack.com/drivetrainte ... index.html

http://www.camaros.org/bellhousings.shtml


5) Your opinion on reusing ARP flywheel bolts? I've heard some people say that by design, when you torque them, they undergo plastic deformation and if you reuse them and retorque them again that additional plastic deformation significantly reduces the yield strength. Could just be BS though. Maybe they don't plastically deform.

Brad

Id re-use them with lock-tite, on the threads and use a torque wrench, I have for many years and NEVER a problem, or even heard of a problem
 
REALLY appreciate the advice.

1) Already using offset alignment dowels. That takes care of 2-axises (x-y) the parallelism specification that's off is the third axis (z). I could probably sacrifice my feeler gauge for $5.

2) I'll try the balancer puller idea on the bushing maybe Monday and post how it works.

3) I'll reuse the flywheel bolts with lock-tight w/o fear.

Thanks!
Brad
 
Used the harmonic balancer puller and a socket to press in the pilot bushing. Seemed to work well but the bushing is just shy of 1/16" above the surface of the crank bore. Put in the transmission without the clutch though and there didn't seem to be any interference.

Still stewing about the runout of the face of the bellhousing. The bottom is about 0.005 higher than the top. Hard to find a good spec. Some say 0.002, some say 0.005 and some say 0.010. I'm on the fence about taking it out to have it milled.

Sent an email to ARP and they responded that their flywheel bolts can be reused.

Brad

P1010194.jpg
 
thanks for posting that clear picture!
its a real pleasure to find someone with photographic skills
 
"HEY grumpy? I have a bad crank pilot bearing, I Was using a slide hammer on it, but its so far gone, that All the needles and the cage are gone and I have the inner edge all bent over so the slide hammer isn't working very well. Was hitting it pretty good with the slide hammer but no luck.
Any tips on an easy way to get the remnants of this bearing out? Was thinking about trying to split it with a chisel but don't want to score the bore of the crankshaft".
IF you need to remove the old pilot bearing, a ounce of thick bearing grease
molygr.png

http://www.machinerylubrication.com/Read/28632/use-right-grease
and an aluminum or wood dowel and a couple hard whacks with a ball peen hammer hydraulically removes the bearing, just wrap electrical tape on the dowel to reduce clearance, if its required to get a decent seal.
pilot_bushing_removal.jpg



wornbearq.jpg


when they get really deformed you can thread in a bottom tap of the correct size that effectively acts like a thread jack and pulls the deformed bearing in many cases, use of FREEZE SPRAY directly on the bearing while slightly heating the crank flange with a propane torch also tends to make removal easier
dcp2.jpg

OBVIOUSLY THE THREADS ON THE TAP MUST BE LARGER IN DIAMETER THAN THE HOLE IN THE BUSTED BEARING TO GET A FIRM GRIP FOR REMOVAL
bottomtap1.jpg

T-wrench.jpg

IF ITS REALLY TORN UP NATIONAL PIPE THREAD TAPS HAVE A GREAT DEAL PF TAPER AND COURSE THREADS THAT MIGHT HELP
npt_threads.png

find the correct thread size tap to fit snugly inside the well worn pilot bearing, and thread the tap into the bearing until its tip bears on the recessed crank hub
heat the crank flange briefly with propane torch
propanetorch.gif

spray the pilot bearing for a minimum of 5-6 seconds with
http://www.loctitefreezeandrelease.com/
freeze.jpg

LoctiteFreeze&Release.JPG

http://www.amazon.com/Loctite-Freeze-Re ... B001VXU474
then thread the pilot bearing out, using the bottoming tap as a thread jack that has a firm grip on the worn bearings interior surface as it bears against the bottom of the crank recess as the temp change between the two components, the pilot bearing diameters been reduced in diameter slightly by the temp change, and heating the crank flange has been slightly expanded by the propane torch.

Pilot bushing clearance to trans input shaft should be .001 to .004
...with .002-.003 being considered about ideal,and the common brass pilot bearing
brasspilot.jpg

should be greased on install, but manufacturers parts vary and .005-.006 clearance to account for a bit of bell housing miss alignment and heat expansion is common.


http://www.machinerylubrication.com/Read/28632/use-right-grease

read this thread also
http://garage.grumpysperformance.co...ole-bearing-replacement-tools-required.16296/
 
Last edited by a moderator:
love the tap trick if the cage break.
I did not think about it but when rebuilding my supercharger i will be dealing with very similar bearings, so that will make life alot easier if/when a bearing's cage break on me :D.
 
"HEY grumpy? I have a bad crank pilot bearing, I Was using a slide hammer on it, but its so far gone, that All the needles and the cage are gone and I have the inner edge all bent over so the slide hammer isn't working very well. Was hitting it pretty good with the slide hammer but no luck.
Any tips on an easy way to get the remnants of this bearing out? Was thinking about trying to split it with a chisel but don't want to score the bore of the crankshaft".
IF you need to remove the old pilot bearing, a ounce of thick bearing grease
molygr.png

http://www.machinerylubrication.com/Read/28632/use-right-grease
and an aluminum or wood dowel and a couple hard whacks with a ball peen hammer hydraulically removes the bearing, just wrap electrical tape on the dowel to reduce clearance, if its required to get a decent seal.
pilot_bushing_removal.jpg



wornbearq.jpg



when they get really deformed you can thread in a bottom tap of the correct size that effectively acts like a thread jack and pulls the deformed bearing in many cases, use of FREEZE SPRAY directly on the bearing while slightly heating the crank flange with a propane torch also tends to make removal easier
dcp2.jpg

OBVIOUSLY THE THREADS ON THE TAP MUST BE LARGER IN DIAMETER THAN THE HOLE IN THE BUSTED BEARING TO GET A FIRM GRIP FOR REMOVAL
bottomtap1.jpg

T-wrench.jpg

IF ITS REALLY TORN UP NATIONAL PIPE THREAD TAPS HAVE A GREAT DEAL PF TAPER AND COURSE THREADS THAT MIGHT HELP
npt_threads.png

find the correct thread size tap to fit snugly inside the well worn pilot bearing, and thread the tap into the bearing until its tip bears on the recessed crank hub
heat the crank flange briefly with propane torch
propanetorch.gif

spray the pilot bearing for a minimum of 5-6 seconds with
http://www.loctitefreezeandrelease.com/
freeze.jpg

LoctiteFreeze&Release.JPG

http://www.amazon.com/Loctite-Freeze-Re ... B001VXU474
then thread the pilot bearing out, using the bottoming tap as a thread jack that has a firm grip on the worn bearings interior surface as it bears against the bottom of the crank recess as the temp change between the two components, the pilot bearing diameters been reduced in diameter slightly by the temp change, and heating the crank flange has been slightly expanded by the propane torch.

Pilot bushing clearance to trans input shaft should be .001 to .004
...with .002-.003 being considered about ideal,and the common brass pilot bearing
brasspilot.jpg

should be greased on install, but manufacturers parts vary and .005-.006 clearance to account for a bit of bell housing miss alignment and heat expansion is common.


http://www.machinerylubrication.com/Read/28632/use-right-grease
 
I have a way to get my pilot bushing out that you'll probably laugh at. I use bread, yes I said bread. I pack the bore with bread & use a dowel to force the bushing out. No greasy mess. The dowel has to be close to the bore size to work properly.
 
Yes, I did get a chuckle out of that suggestion ..... bread !

Do you have it for a snack after the bushing is out ? :D
 
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