Pilot Bushing Installation

Discussion in 'transmission and Drive train' started by brad.arcova, Dec 5, 2009.

  1. brad.arcova

    brad.arcova Member

    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
     
  2. grumpyvette

    grumpyvette Administrator Staff Member

    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 [​IMG]
    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
    [​IMG]
    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



    [​IMG]
    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
    [​IMG]
    http://www.harborfreight.com/cpi/ctaf/d ... mber=95853
    [​IMG]

    http://www.dormanproducts.com/p-11019-690-014.aspx
    [​IMG]
    [​IMG]
    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/
    [​IMG]
    and
    SINTERED BRONZE PILOT BEARINGS
    http://www.summitracing.com/parts/RAM-BU656/
    [​IMG]
    [​IMG]
    [​IMG]
    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.
    [​IMG]
    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: Feb 18, 2017
  3. brad.arcova

    brad.arcova Member

    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
     
  4. grumpyvette

    grumpyvette Administrator Staff Member

    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
     
  5. brad.arcova

    brad.arcova Member

    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
     
  6. brad.arcova

    brad.arcova Member

    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

    [​IMG]
     
  7. grumpyvette

    grumpyvette Administrator Staff Member

    thanks for posting that clear picture!
    its a real pleasure to find someone with photographic skills
     
  8. grumpyvette

    grumpyvette Administrator Staff Member

    "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
    [​IMG]
    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.
    [​IMG]

    [​IMG]


    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
    [​IMG]
    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
    [​IMG]
    [​IMG]
    IF ITS REALLY TORN UP NATIONAL PIPE THREAD TAPS HAVE A GREAT DEAL PF TAPER AND COURSE THREADS THAT MIGHT HELP
    [​IMG]
    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
    [​IMG]
    spray the pilot bearing for a minimum of 5-6 seconds with
    http://www.loctitefreezeandrelease.com/
    [​IMG]
    [​IMG]
    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 [​IMG]
    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
     
    Last edited by a moderator: Oct 8, 2016
  9. mathd

    mathd solid fixture here in the forum

    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.
     

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