Author Topic: Front Wheel bearing stuck  (Read 2817 times)

0 Members and 2 Guests are viewing this topic.

Offline Nayl

  • Full Member
  • *
  • Posts: 77
Front Wheel bearing stuck
« on: May 07, 2016, 05:21:51 PM »
Working on removing the front wheel bearings on my '76 F1, I generally tend to bugger up anything that involves improvised driving/hammering, so I went and got the Harbor Freight blind puller for  the job.  And it fits just fine.  Thing is, after about a solid half hour of whacking away with that three pound slide hammer, I'm getting zero movement.  Tried the other side, same deal.  I very much doubt anyone ever had this wheel apart before (I had to drill out the marks in  the retainer)  so what's stopping me? 

Offline evanphi

  • Apparently I'm an
  • Old Timer
  • ******
  • Posts: 3,107
  • Rhonda the Basket Case
Re: Front Wheel bearing stuck
« Reply #1 on: May 08, 2016, 04:53:44 AM »
Apply heat with a propane torch.

Try again.
--Evan

1975 CB750K "Rhonda"
Delkevic Stainless 4-1 Header, Cone Engineering 18" Quiet Core Reverse Cone, K&N Filter in Drilled Airbox
K5 Crankcase/Frame, K4 Head and Cylinders, K1 Carbs (42;120;1 Turn)

She's a mix-matched (former) basket case, but she's mine.

CB750 Shop Manual (all years), searchable text PDF
Calculating the correct input circumference for digital speedometers connected to the original speedometer drive

Offline jamesw

  • Hot Shot
  • ***
  • Posts: 323
Re: Front Wheel bearing stuck
« Reply #2 on: May 08, 2016, 12:00:50 PM »
If the 76F is the same as my 75K, what I did that worked was put the wheel on a saw horse, hammer the center of the bearing (I used an old axle as a punch).....after a few whacks, you should see the opposite bearing on the flip side move out a bit. Then you should be able to slide the inner collar to one side. After doing this, get a screwdriver and hit the end of the screwdriver and drive the bearing out using the collar.
72K-F 750 Cafe
75K 750 Cafe
75F 750 Restoration

Offline Nayl

  • Full Member
  • *
  • Posts: 77
Re: Front Wheel bearing stuck
« Reply #3 on: May 08, 2016, 01:18:27 PM »
Quote
If the 76F is the same as my 75K
I doubt there's any difference, do you recall if you did this from the speedo drive side or the other?

Quote
Apply heat with a propane torch.

Tried that just now, assuming that I should be heating the hub to get it to expand away from the bearing.  Hit the hub flange that surrounds the bearing for a solid three minutes or so, don't know how hot it really got, but made zero difference to pulling the bearing.  I hesitate to get more aggressive than propane with heating an aluminum hub, maybe get some dry ice next and try it on the bearing.

Offline PeWe

  • Really Old Timer ...
  • *******
  • Posts: 15,563
  • Bike almost back to the 70's 2015
Re: Front Wheel bearing stuck
« Reply #4 on: May 08, 2016, 02:08:53 PM »
Electric heat gun work really well for bearings (before mounting or removing), making carb boots soft, fork seals before removal and before mounting new seals. 17 USD version here has worked for a copule of years with my CB750 restore
http://www.biltema.se/sv/Verktyg/Elverktyg/Ovrigt/Varmluftspistol-20-kW-2000021758/
« Last Edit: May 08, 2016, 02:11:02 PM by PeWe »
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967

Offline jamesw

  • Hot Shot
  • ***
  • Posts: 323
Re: Front Wheel bearing stuck
« Reply #5 on: May 08, 2016, 02:44:33 PM »
I don't recall off hand. I can check in the morning as Im at work right now. I followed the steps in Hondaman's book for replacing bearings, and it worked like a charm.

Once you can move the collar and hit with the screwdriver driving it out, it comes right out. I had the original bearings in there too.
« Last Edit: May 08, 2016, 02:46:05 PM by jamesw »
72K-F 750 Cafe
75K 750 Cafe
75F 750 Restoration

Offline przjohn

  • Expert
  • ****
  • Posts: 948
Re: Front Wheel bearing stuck
« Reply #6 on: May 08, 2016, 03:10:38 PM »
Heat it with a torch until the grease in the bearing catches fire. With all due respect to previous posts, don't waste your time with a heat gun, more heat the faster, the better. You want that hub to get hot real fast and not the bearing.
I like poetry, long walks on the beach, and poking at dead things with a stick.

Offline Nayl

  • Full Member
  • *
  • Posts: 77
Re: Front Wheel bearing stuck
« Reply #7 on: May 10, 2016, 01:26:32 PM »
Well, that was educational.  Something to be said for the "use a bigger hammer" approach, or, in this case, if one propane torch isn't doing the job, use two.  After two failed attempts where I was getting the distinct feeling I wasn't getting enough heat fast enough, I broke out the second torch and after a solid five or six minutes of hitting both sides of the hub at once (by which point the slide weight was actually getting warm) it finally popped out.

Offline flybox1

  • My wife thinks I'm a
  • Really Old Timer ...
  • *******
  • Posts: 14,301
Re: Front Wheel bearing stuck
« Reply #8 on: May 10, 2016, 01:37:49 PM »
Yeah...that job always calls for a BFH.
'78 750K (F3 engine) PD42b's, Modified airbox w/K&N  filter, 40/110 jets, 1 needle shim, IMS@ 1 turn out. Kerker + Cone 18" QuietCore

Past Bikes
1974 550K0 (stock), 1973 CB350F (stock), 1983 Yamaha XS400K (POS)
77/78 cool 2 member #3
"Knowledge without mileage equals bullsh!t" - Henry Rollins

"This is my CB. There are many like it, but this one is mine…"

Offline 70CB750

  • Labor omnia vincit improbus.
  • Really Old Timer ...
  • *******
  • Posts: 14,800
  • Northern Virginia
Re: Front Wheel bearing stuck
« Reply #9 on: May 11, 2016, 04:17:45 AM »
I had good experience with Mapp gas, price but heats well.
Prokop
_______________
Pure Gas - find ethanol free gas station near you

I love it when parts come together.

Dorothy - my CB750
CB750K3F - The Red
Sidecar


CB900C

2006 KLR650

Offline nobody

  • Hot Shot
  • ***
  • Posts: 527
Re: Front Wheel bearing stuck
« Reply #10 on: May 11, 2016, 09:38:46 AM »
I've been glaring at my wheel bearings for a couple weeks now, they're glaring back at me too.

I don't have the spanner tool for the retainers, and can't get the front speedo assembly to release after disconnecting everything.
A local shop says they'll change the four bearings and balance my wheels for $100-120, seems steep but the labor also seems intensive.
74 cb750k

If life hands you lemons, make lemonade. If life hands you tomatoes, make tomato soup. If life hands you a box of hand grenades... well, now... THAT'S a message!!

Offline flybox1

  • My wife thinks I'm a
  • Really Old Timer ...
  • *******
  • Posts: 14,301
Re: Front Wheel bearing stuck
« Reply #11 on: May 11, 2016, 09:42:33 AM »
I've been glaring at my wheel bearings for a couple weeks now, they're glaring back at me too.

I don't have the spanner tool for the retainers, and can't get the front speedo assembly to release after disconnecting everything.
A local shop says they'll change the four bearings and balance my wheels for $100-120, seems steep but the labor also seems intensive.
You dont need no spanner tool for the retainers.  ;D  Drill out the stakes, and use a punch and a BFH to spin it out.
Clean the threads of the hub and the retainer.  Install it on top of your new bearings. Use the punch to spin it tight. 
Add a few new stakes.  Done ;)
« Last Edit: May 11, 2016, 09:45:34 AM by flybox1 »
'78 750K (F3 engine) PD42b's, Modified airbox w/K&N  filter, 40/110 jets, 1 needle shim, IMS@ 1 turn out. Kerker + Cone 18" QuietCore

Past Bikes
1974 550K0 (stock), 1973 CB350F (stock), 1983 Yamaha XS400K (POS)
77/78 cool 2 member #3
"Knowledge without mileage equals bullsh!t" - Henry Rollins

"This is my CB. There are many like it, but this one is mine…"