HarleyTechTalk

Gents,

I am in the middle of a cam swap on my 2017 FLHTK.  The factory service manual tells you that when replacing the cam bearing it must be reseated to the same depth in the crankcase (and does NOT bottom out when fully seated as with cam bearings on twin cams).  I own the George's Garage M8 cam bearing install tool, so prior to pulling the original factory bearing I measured the distance from the top of my bearing installer plate to the front face of the old bearing with a set of calipers. 


With that bearing depth information in hand, I unbolted the plate and pulled the OEM bearing with a George's Garage bearing puller tool. 





With the old bearing out, I next reattached the bearing installation plate to the camchest.  After applying a film of motor oil on to my new/replacement bearing, I began to drive the bearing forward in to its place in the camchest.  I encountered no issues and very little resistance as the bearing began to seat in the crank case. 

I found that it was easy to gradually move the bearing forward a little at a time with the tool, then back the tool out and reach inside the camchest to feel if the bearing was still protruding from the face of the case.  I'd then tighten the tool by hand until it was touching the face of the bearing and then seat it a little deeper by tightening the adjusting bolt further with my wrench.  The original bearing had been seated so that it was slightly below flush with the edge of the crank case. Since I didn't want to overshoot and seat it too deep, I stopped with the bearing edge a little above the crankcase and rechecked the math on my how deeper it needed to sink.  The math showed it needed it be .137 inches deeper, which equates to just under 2.5 complete revolutions (since the adjusting screw is 18 TPI each full revolution equates to 0.0556 inches).  I decided to give it 1.5 revolutions and then recheck the seating depth progress.  I encountered significantly more resistance and had to apply a large amount of force to get it to turn the last bit.  I don't think I even got the full portion of 1.5 turns in place when it felt like the bearing had bottomed out and couldn't turn any further. 

According to my original calculations, it still needs to seat an additional 0.072 inches further.  The tolerance range in the service manual is +/- 0.020 inches of the original measurement, so I am definitely outside of that.  Alarmed, I decided to pull the bearing out and see if there was an issue in the engine case that was preventing the bearing from fully seating.  I can see and feel a distinctive lip inside the crankcase hole.  It looks like that's likely the issue that's keeping the bearing from seating deeper in the hole.



Is that ledge normally there?  Did I somehow do damage to the crankcase when removing the factory bearing or installing the replacement bearing?   

Looks like a frost plug in there. Did you push it up against the flywheel while pressing the bearing in?
Ron

Quote from: rbabos on November 11, 2019, 03:51:02 PM
Looks like a frost plug in there. Did you push it up against the flywheel while pressing the bearing in?
Ron

No, it didn't seat against the flywheel.  In any event I wouldn't have been able to get the collet on the bearing puller tool to grab / purchase against the backside of the bearing when I pulled the bearing the second time.  It's definitely stopping against the ledge in the crankcase.  Am I overthinking things?  Is that a machined in shoulder / stop that's supposed to be there?

That back stop edge is normal.  All inner bearing bores have them, and yes they are there to prevent the bearing from going into the casing under any and all situations.  Did you install the bearing with the letters facing you?  In other words, with the flat side of the bearing facing you?

BTW, you didn't do any damage to your casing.  It's still as good as new.

Bearing seating calculations are something I have done for almost 40 years in the jet engine business.

Don`t use the old bearing for reference, it may not be the same width as the new bearing, or it may have been seated improperly-don`t assume an installed part is correct...

Measure the width of the new bearing, and the depth of the bearing seating shoulder in the bore.

Subtract the bearing width from the shoulder depth, that will tell you exactly how deep the (new) installed bearing should be below the surface (if you get a negative number, it means the installed bearing will be above the surface).

You can over think this too. All you need to make sure of is that the cam shaft has end play during assembly. If you drive the bearing in, set the cam and cam plate in place and the cam moves back and forth before you install the cam sprocket  you should be fine.

Quote from: les on November 11, 2019, 04:37:44 PM
That back stop edge is normal.  All inner bearing bores have them, and yes they are there to prevent the bearing from going into the casing under any and all situations.  Did you install the bearing with the letters facing you?  In other words, with the flat side of the bearing facing you?

Quote from: les on November 11, 2019, 04:39:50 PM
BTW, you didn't do any damage to your casing.  It's still as good as new.

Great to hear that the back stop edge is supposed to be there / engine case is fine.  And yes, the bearing was installed with the letter facing me.

Quote from: Dan89flstc on November 11, 2019, 04:42:47 PM
Bearing seating calculations are something I have done for almost 40 years in the jet engine business.

Don`t use the old bearing for reference, it may not be the same width as the new bearing, or it may have been seated improperly-don`t assume an installed part is correct...

Measure the width of the new bearing, and the depth of the bearing seating shoulder in the bore.

Subtract the bearing width from the shoulder depth, that will tell you exactly how deep the (new) installed bearing should be below the surface (if you get a negative number, it means the installed bearing will be above the surface).

Outstanding post.  I always like knowing the why of a procedure.

Quote from: PoorUB on November 11, 2019, 05:10:46 PM
You can over think this too. All you need to make sure of is that the cam shaft has end play during assembly. If you drive the bearing in, set the cam and cam plate in place and the cam moves back and forth before you install the cam sprocket  you should be fine.

Sounds like I was definitely overthinking it.



A fella on another forum was kind enough to mention that he used the same tool that I used (from George's Garage) on his bearing swap and wasn't able to seat the bearing quite as deep as the MoCo did. I just went out to the garage and verified that the shoulder on the bearing install tool is a fair amount wider than the face of the bearing. In fact, it's so wide that the shoulder on the bearing install tool will not physically allow the tool to pass inside the hole in the crankcase where the bearing rests. As a result, once the face of the tool hits the crankcase wall it's impossible to seat the bearing any further.


I should have caught it earlier, but I was so stressed out at the idea of damaging my engine cases that I wasn't thinking clearly.

I would not use that new bearing you pulled out. The inner rolled bearing flange is likely deformed after being pulled on.

Quote from: hulkss on November 11, 2019, 06:58:15 PM
I would not use that new bearing you pulled out. The inner rolled bearing flange is likely deformed after being pulled on.

I have another one on order. 

QuoteAs a result, once the face of the tool hits the crankcase wall it's impossible to seat the bearing any further.

and that's the way it should be and is a sign of a good well made tool

Did you measure the two bearings width,making sure they are the same ?

Quote from: barny7655 on November 11, 2019, 11:37:33 PM
Did you measure the two bearings width,making sure they are the same ?

They are identical.

Ok, just so I got this straight, the M8 cam bore is a blind hole and not a through hole like the TC? That would explain what I'm seeing in the pics then.
Ron

Overthinking is not always a bad thing. Sometimes you have to sit back and review what you did, sleep on it and check it out later to make sure you did not miss something. I did the same thing when I did my M8. I even used my twin cam plate and puller to pull the stock bearing and to start the new bearing. I finished driving in the new bearing by hand with a small body hammer, to just below the machined edge on the outside of the case. Had the in tolerance cam end play and finished up the install. No issues, bike runs great. I may end up taking it back apart this Winter though to inspect the piston oilers, not something I am looking forward to.

Lesson learned for us who have never done this job is that the tool presses the bearing in until flush, when torque on tool increases stop...bearing is fully installed (outer edge of bearing flush to case), correct?

Quote from: rbabos on November 12, 2019, 05:16:48 AM
Ok, just so I got this straight, the M8 cam bore is a blind hole and not a through hole like the TC? That would explain what I'm seeing in the pics then.
Ron

it's not blind

Quote from: FSG on November 12, 2019, 08:58:14 AM

Quote from: rbabos on November 12, 2019, 05:16:48 AM
Ok, just so I got this straight, the M8 cam bore is a blind hole and not a through hole like the TC? That would explain what I'm seeing in the pics then.
Ron

it's not blind

That makes sense. The flywheel was looking like the bottom of the hole in the pic. My mistake.
Ron

looks are deceiving, if you blow the pic up you can see the machining marks on the right wheel 

Quote from: Dan89flstc on November 12, 2019, 06:58:30 AM
Lesson learned for us who have never done this job is that the tool presses the bearing in until flush, when torque on tool increases stop...bearing is fully installed (outer edge of bearing flush to case), correct?

No.  It's just under the surface.  A good tool has a slight step that installs the bearing just below.  Actually there is a taper on the bearing bore, and a proper tool (or proper install) puts the surface of the bearing right at the bottom of that tapered counterbore.

The installer used by Both Jim's and George's is the one for the TC. Both Part Numbers are identical. So, you need not spend the money for the remover or installer if you have one for the TC. The reason being is virtually all have different depth from the factory. Very few are identical. When I spoke with George, the very first thing i asked was when he was making an installer to set the depth. He confirmed what H-D stated. Jimm's did as well when I spoke with them.

Why did I ask? Yes you can push the Bearing into the Flywheel. The very first one I did it bottomed out on the flywheel - We all learned a lesson at my expense.

Get as close to 0.020 as possible. Often it's not even close. Use a Smooth - True - Washer the size of the Race to move it inbound to meet the +/- 0.020. Engineering suggested when I was livid with them concerning my screw-up. Which was 100% my fault!

Just as important, perhaps more so on the M8 is: the Sprocket Alignment - MUST be within 0.009

You marked the crank with the bearing puller taking it out. You are over thinking this push the bearing in until it bottoms out and put it back together you'll be fine. I've done over 20 m8 cams never had an Problem.

QuoteYes you can push the Bearing into the Flywheel.

from my experience working on the TC's the only way to push the bearing up against the flywheel is to firstly break the Lip away at the back of the bearing recess, do that and touching the flywheel is the least of your problems

that lip is there for a purpose and in the early days of TC's it was broken away by a few, some even reported it here on HTT

Now go and look at the business end of any descent tool, here is the TC Tool from Georges Garage




the business end, you should be able to see the step that pushes against the bearing
and the stop stection the touches and stops against the crankcase






here's a plastic one that I made for that just in case time

Quote from: FSG on November 14, 2019, 02:28:33 PM

QuoteYes you can push the Bearing into the Flywheel.

from my experience working on the TC's the only way to push the bearing up against the flywheel is to firstly break the Lip away at the back of the bearing recess, do that and touching the flywheel is the least of your problems

that lip is there for a purpose and in the early days of TC's it was broken away by a few, some even reported it here on HTT

Now go and look at the business end of any descent tool, here is the TC Tool from Georges Garage




the business end, you should be able to see the step that pushes against the bearing
and the stop stection the touches and stops against the crankcase






here's a plastic one that I made for that just in case time

i was referring to the M-8. I "assumed" it was the same as the TC - I used the incorrect end (early TC as I had just done one - Dumb Ass).Trying to set the depth i did it in a hurry. All the way through into the Flywheel. Oops! Instead of allowing the tool to align it i aligned it with my fingers (as it was loose obviously).

On another note, for whatever reason, the right side case's are different on the M-8. I have used spacers more since the M-8 than all the TC and EVO combined!

You wouldn't think so as i would think they're all forged by the same contractor. Maybe they have several different molds with differing tooling. I have seen overall differences of +- .012 when measuring the original set-point on the Factory Installed Bearing.

So, regarding that lip on a decent tool like JIMS or GG.  If you look at a properly installed bearing before you remove it, you will see that its face is just about right at the bottom of the counterbore.  Then if you install the new bearing with a decent lipped tool, you'll see [again] that's its face is right about at the bottom of the counterbore.

I bought a late model twin cam SE installer tool, when the 2007's first came out.  The stupid H-D tool did not have a lip.  The tool was the same size as the bearing...no against the case stopper.  H-D says to put in, take a look, push in, take a look, push in, take a look...crazy...stupid.

What I ended up doing, even before I installed my first late model twin cam bearings is the to a bunch of measurements on the H-D tool.  Then I had a friend machine me up a exact measured collar that goes between the pusher bolt head and when that collar grounds against the mounting plate, the bearing is installed at the exact correct depth, which off the top of my head I think is 3.1"...whatever it says in the H-D service manual.  Now I just ram the bearing right in with the tool, and the cool little collar stops me dead when I'm there.