testy

Author Topic: Engine Bearing Replacement  (Read 12538 times)

0 Members and 1 Guest are viewing this topic.

Offline Kickstart

  • Expert
  • ****
  • Posts: 790
Re: Engine Bearing Replacement
« Reply #25 on: September 20, 2012, 08:48:56 pm »

One thing I'd like to add: the bearing #22 in this picture is a #6205 Extra Clearance bearing. While standard bearings will work, they will make the shifting of gears 3,4 & 5 stiff when the engine is hot or under power because of the twisting of the crankcases. The Extra Clearance bearings can be had from any bearing house: they are usually associated with very tight press-fitted holes, but here they serve a different purpose. The Extra Clearance is about 0.0004" in the races, to prevent bind and power loss (and extra heating).  :)
[/quote]

I know this is an old thread, but others will probably find this when searching, and I think there's a mistake here.

Mark, I believe it's bearing #23 6304NR that is the HS (extra clearance) one.  You specify this in your book, and I also noticed the part description on bikebandit shows HS for this bearing.

I believe the correct list should be:

2 x HK2520 Needle Rollers
1 x 3206ATN9 Roller Bearing
1 x 6003 Roller Bearing
1 x 6008NR Roller Bearing
1 x 6204 Roller Bearing
1 x 6205 Roller Bearing
1 x 6205NR Roller Bearing
1 x 6304 Roller Bearing
1 x 6304NR/C3 Roller Bearing


I don't mean to point out mistakes, I just want to make sure others who search for this get the correct information.
« Last Edit: April 23, 2018, 04:36:22 am by Glenn Stauffer »
- Chris
75' CB750F Orange flake (rider)
75' CB750F Blue (Project)
75' CB750F Painted black (Project)
No Reserve Racing #171 AHRMA

Offline HondaMan

  • Someone took this pic of me before I became a
  • Moderator
  • Really Old Timer ...
  • *****
  • Posts: 9,051
  • ...not my choice, I was nicknamed...
    • Getting 'em Back on the Road
Re: Engine Bearing Replacement
« Reply #26 on: September 23, 2012, 10:42:00 pm »
You're correct about the "C3" designation for extra-clearance bearings. Today, I am finding that many bearing-house employees don't have a clue about that designation, though.

However...if you ask them for an "electric motor shaft bearing", they will [accidentally] get you the very same C3 part. ;)
The demons are repulsed when a man does good. Use that.
Blood is thicker than water, but motor oil is thicker yet...so, don't mess with my SOHC4, or I might have to hurt you.
Hondaman's creed: "Bikers are family. Treat them accordingly."

Link to Hondaman Ignition: http://forums.sohc4.net/index.php?topic=67543.0

Link to My CB750 Book: http://forums.sohc4.net/index.php?topic=65293.0

Link to website: www.SOHC4shop.com

Offline Kickstart

  • Expert
  • ****
  • Posts: 790
Re: Engine Bearing Replacement
« Reply #27 on: September 24, 2012, 05:52:13 pm »
You're correct about the "C3" designation for extra-clearance bearings. Today, I am finding that many bearing-house employees don't have a clue about that designation, though.

However...if you ask them for an "electric motor shaft bearing", they will [accidentally] get you the very same C3 part. ;)

Funny... I think I ran into this problem just this morning.
I went to my local authorized SKF distributor with bearings in hand. I mentioned I wanted the one bearing as an "extra clearance - C3" and the guy was confused.  He asked me if I was sure about it being a C3, because "C3 is the standard clearance".  We then discussed getting C2 for the others, but they gave me nervous looks and said something about it possibly being too tight.  I didn't end up ordering because now I was confused.

What is the standard clearance for our bearings?... I'm guessing if c3 is extra clearance, maybe c2? [Edit - c2 is less clearance than normal... normal is just "Normal"]
« Last Edit: October 01, 2012, 07:02:30 am by Kickstart »
- Chris
75' CB750F Orange flake (rider)
75' CB750F Blue (Project)
75' CB750F Painted black (Project)
No Reserve Racing #171 AHRMA

Offline Kickstart

  • Expert
  • ****
  • Posts: 790
Re: Engine Bearing Replacement
« Reply #28 on: October 01, 2012, 06:37:13 am »
I was just on the SKF website.  C2 has less clearance than a "normal":
http://www.skf.com/skf/productcatalogue/jsp/viewers/tableViewer.jsp?tableName=1_1_t3&maincatalogue=1&lang=en

So you need to state "Normal" for most of the bearings and "C3" for the 6304NR (and the 6205 if you're following the recommendation in HondaMan's book).

I guess if the bearing shop you go to confuses you by saying C3 is normal... you should politely leave as I did :)


- Chris
75' CB750F Orange flake (rider)
75' CB750F Blue (Project)
75' CB750F Painted black (Project)
No Reserve Racing #171 AHRMA

Offline Kickstart

  • Expert
  • ****
  • Posts: 790
Re: Engine Bearing Replacement
« Reply #29 on: October 01, 2012, 07:01:15 am »
Has anyone had trouble with the standard snap-ring groove dimensions?
I thought I saw another post where someone said they couldn't get the retainer ring to fit into the groove.

I mic'd the thickness of the retainer ring on my 6008 bearing:  it was 0.0787 inches (1.99898 mm).
Per the SKF specifications, the standard groove is only 1.9mm
http://www.skf.com/skf/productcatalogue/Forwarder?action=PPP&lang=en&imperial=false&windowName=null&perfid=105033&prodid=1050330008

Also, the depth of the groove seems a little too deep.  Spec shows 1.59mm.  I didn't measure the depth on mine, but per the diagram in HM's book it's only 1.25mm deep (although, I assume that measurement isn't as critical).

- Chris
75' CB750F Orange flake (rider)
75' CB750F Blue (Project)
75' CB750F Painted black (Project)
No Reserve Racing #171 AHRMA

Offline Kickstart

  • Expert
  • ****
  • Posts: 790
Re: Engine Bearing Replacement
« Reply #30 on: December 30, 2012, 08:17:41 pm »
OK... I haven't been on the board in a while.

But I did get my new bearings about month ago.  I ordered one of them with the the groove and snap-ring just to see if the groove would work with the existing retaining half ring.

Unfortunately, the retaining half-ring does not fit in the new bearing's groove.  The new bearing's groove is just a little too narrow. 

It's not that big of a deal for me since I still need to have my machinist cut the grooves in the other two bearings anyway... I'll just have him enlarge this one as well.  But for those of you ordering new bearings I would suggest ordering them without the snap-ring and find a machinist to cut the groove to the correct specification for our bikes.

- Chris
75' CB750F Orange flake (rider)
75' CB750F Blue (Project)
75' CB750F Painted black (Project)
No Reserve Racing #171 AHRMA

Offline Terry in Australia

  • Really Old Timer ...
  • *******
  • Posts: 24,018
  • So, what do ya wanna talk about today?
Re: Engine Bearing Replacement
« Reply #31 on: December 31, 2012, 01:34:47 am »
Your machinist is gonna have fun trying to cut a groove in a bearing's outer ring mate, I doubt if his cutting tools will be harder than the material that he's trying to cut.

He Might be able to grind a slot into it if he's got a thin cutting disc and a steady hand, but otherwise, I can't see it happening.

Not wanting to rain on your parade mate, but I've tried cutting hardened steel before, with limited success. Cheers, Terry. ;D
I was feeling sorry for myself because I couldn't afford new bike boots, until I met a man with no legs.

So I said, "Hey mate, you haven't got any bike boots you don't need, do you?"

Offline bert96

  • past ride
  • Expert
  • ****
  • Posts: 1,230
Re: Engine Bearing Replacement
« Reply #32 on: November 02, 2013, 09:52:23 am »


I know it's an old thread BUT i can't find a place where i could buy C2 bearings,they simply don't have these bearings!?

Canadian bearings don't have it either .They only have C3

Where do you guys find these bearings?


Bert
QA50 1969,ST-90 1974,mb5 1982,rz350 1983,shadow 1100 1985,vf1000f 1985,BMW K1 1990,shadow tourer 1100 2001,vfr 750 1994,vtr250 199?

Offline City Boy

  • Hot Shot
  • ***
  • Posts: 682
Re: Engine Bearing Replacement
« Reply #33 on: November 02, 2013, 12:53:31 pm »
Hondaman,could you respond to Kickstarts note that extra clearance bearing is #23 on mainshaft as opposed to #22 which you mentioned in an earlier post.I am a bit confused. Thanks.   Jim
'52 Kiekhaefer Mercury Rocket Hurricane KG4H
'70 750/RC 1000 Original Owner
'83 1100F

Offline Terry in Australia

  • Really Old Timer ...
  • *******
  • Posts: 24,018
  • So, what do ya wanna talk about today?
Re: Engine Bearing Replacement
« Reply #34 on: November 02, 2013, 05:32:12 pm »
Sorry Bert, I've only used OEM bearings in CB750 transmissions, in my experience, they very rarely wear out. Cheers, Terry. ;D
I was feeling sorry for myself because I couldn't afford new bike boots, until I met a man with no legs.

So I said, "Hey mate, you haven't got any bike boots you don't need, do you?"

Offline bert96

  • past ride
  • Expert
  • ****
  • Posts: 1,230
Re: Engine Bearing Replacement
« Reply #35 on: November 02, 2013, 05:34:54 pm »
Thanks Mick, I've used SKF bearings before with no issues, they were great.  ;)

You use only OEM bearings????! are you sure ;)
QA50 1969,ST-90 1974,mb5 1982,rz350 1983,shadow 1100 1985,vf1000f 1985,BMW K1 1990,shadow tourer 1100 2001,vfr 750 1994,vtr250 199?

Offline Terry in Australia

  • Really Old Timer ...
  • *******
  • Posts: 24,018
  • So, what do ya wanna talk about today?
Re: Engine Bearing Replacement
« Reply #36 on: November 02, 2013, 05:46:47 pm »
Yes Bert, I've used SKF bearings for wheels, but not in engines. I'm sure they're fine, I just haven't used them in an engine. Cheers, Terry. ;D
I was feeling sorry for myself because I couldn't afford new bike boots, until I met a man with no legs.

So I said, "Hey mate, you haven't got any bike boots you don't need, do you?"

Offline Kickstart

  • Expert
  • ****
  • Posts: 790
Re: Engine Bearing Replacement
« Reply #37 on: November 02, 2013, 09:33:07 pm »


I know it's an old thread BUT i can't find a place where i could buy C2 bearings,they simply don't have these bearings!?

Canadian bearings don't have it either .They only have C3

Where do you guys find these bearings?


Bert


nobody?

I need a little bit of help!


Bert

You don't want C2, that was a bad assumption I made - I believe I corrected/edited my statement below.

You just want "normal".  BUT... normal is NOT C3 (also known as JEM).  Your bearing place should be able to order it.  I was able to find a bearing place that knew the difference and ordered mine for me.


- Chris
75' CB750F Orange flake (rider)
75' CB750F Blue (Project)
75' CB750F Painted black (Project)
No Reserve Racing #171 AHRMA

Offline Kickstart

  • Expert
  • ****
  • Posts: 790
Re: Engine Bearing Replacement
« Reply #38 on: November 02, 2013, 09:43:56 pm »
Hondaman,could you respond to Kickstarts note that extra clearance bearing is #23 on mainshaft as opposed to #22 which you mentioned in an earlier post.I am a bit confused. Thanks.   Jim

I'm pretty sure Hondaman just got those mixed up in his post, as his book mentions the 6304NR one needing to be the HS (or extra clearance one).... you can also double check by looking at the bearings in your engine... I think that original bearing might have "HS" stamped on it as well.

At least, I hope so, because that's what I bought to put back in my bike. :)
- Chris
75' CB750F Orange flake (rider)
75' CB750F Blue (Project)
75' CB750F Painted black (Project)
No Reserve Racing #171 AHRMA

Offline Kickstart

  • Expert
  • ****
  • Posts: 790
Re: Engine Bearing Replacement
« Reply #39 on: November 02, 2013, 09:48:30 pm »
Your machinist is gonna have fun trying to cut a groove in a bearing's outer ring mate, I doubt if his cutting tools will be harder than the material that he's trying to cut.

He Might be able to grind a slot into it if he's got a thin cutting disc and a steady hand, but otherwise, I can't see it happening.

Not wanting to rain on your parade mate, but I've tried cutting hardened steel before, with limited success. Cheers, Terry. ;D

My machinist was able to do it... sure enough it was harder than he though it would be... he had to purchase some special bit (he showed it to me, but I don't remember what type it was or anything).

Wasn't cheap - charged me $40 per bearing as I recall.... but yes, I've got the grooves all perfectly cut.

Someday I'll actually put the engine back together.  :)
- Chris
75' CB750F Orange flake (rider)
75' CB750F Blue (Project)
75' CB750F Painted black (Project)
No Reserve Racing #171 AHRMA

Offline Terry in Australia

  • Really Old Timer ...
  • *******
  • Posts: 24,018
  • So, what do ya wanna talk about today?
Re: Engine Bearing Replacement
« Reply #40 on: November 03, 2013, 12:07:20 am »
40 bucks per bearing just to get the grooves cut? Ouch! I'd be interested to see the tool that he used, all I could think of was a fine cutting disc, I couldn't imagine a lathe or milling machine tool that could cut a hardened steel bearing case, the case is probably as hard as the bearings? Cheers, Terry. ;D 
I was feeling sorry for myself because I couldn't afford new bike boots, until I met a man with no legs.

So I said, "Hey mate, you haven't got any bike boots you don't need, do you?"

Offline Medyo Bastos

  • Expert
  • ****
  • Posts: 946
  • Gusto mo titi ko?
    • project
Re: Engine Bearing Replacement
« Reply #41 on: November 03, 2013, 06:09:53 am »
...the case is probably as hard as the bearings? Cheers, Terry. ;D

or supermans knee caps!

Offline bert96

  • past ride
  • Expert
  • ****
  • Posts: 1,230
Re: Engine Bearing Replacement
« Reply #42 on: November 03, 2013, 09:21:46 am »


It's more clearer,thanks guys for your help!


Bert
QA50 1969,ST-90 1974,mb5 1982,rz350 1983,shadow 1100 1985,vf1000f 1985,BMW K1 1990,shadow tourer 1100 2001,vfr 750 1994,vtr250 199?

Offline Justin

  • Enthusiast
  • **
  • Posts: 160
    • Cj's Garage
Re: Engine Bearing Replacement
« Reply #43 on: May 28, 2015, 02:32:35 pm »
Bringing this topic back from the dead for one important question: Are these bearings for ALL CB750 SOHCs, or just for early ones, just for later ones? Hopefully there is some insight into this. I'm about to order new bearings for my 71 cb750 k1

Offline wohali

  • What, me worry?
  • Hot Shot
  • ***
  • Posts: 274
  • Don Pardo, tell 'em what they've won!
Re: Engine Bearing Replacement
« Reply #44 on: May 28, 2015, 08:45:46 pm »
My understanding is that none of the bearings are different unless you have a CB750A (Hondamatic automatic transmission) which I think has an extra bearing. Don't quote me on that last bit though.

Offline Justin

  • Enthusiast
  • **
  • Posts: 160
    • Cj's Garage
Re: Engine Bearing Replacement
« Reply #45 on: May 28, 2015, 09:43:13 pm »
My understanding is that none of the bearings are different unless you have a CB750A (Hondamatic automatic transmission) which I think has an extra bearing. Don't quote me on that last bit though.

I know from Hondaman's book that at least the final drive bearing was different between models, although I think his book also states that they're interchangeable..

Offline PeWe

  • Really Old Timer ...
  • *******
  • Posts: 6,877
  • Bike almost back to the 70's 2015
Re: Engine Bearing Replacement
« Reply #46 on: May 29, 2015, 03:35:39 am »
My understanding is that none of the bearings are different unless you have a CB750A (Hondamatic automatic transmission) which I think has an extra bearing. Don't quote me on that last bit though.

I know from Hondaman's book that at least the final drive bearing was different between models, although I think his book also states that they're interchangeable..

See service Bulletine from Honda
Russ Collins used a double row bearing in their Cobra build.
CB750 K6-76 1005cc JMR Billet block.
CB750 K2-75 stock looking project started 2017

Offline PeWe

  • Really Old Timer ...
  • *******
  • Posts: 6,877
  • Bike almost back to the 70's 2015
Re: Engine Bearing Replacement
« Reply #47 on: May 29, 2015, 11:59:06 am »
A very informative site that have a good list of the bearings to a CB750F. I think they all are the same as for the K.
https://wrenchandspanner.wordpress.com/2014/12/16/cb750f-transmission-bearings/
CB750 K6-76 1005cc JMR Billet block.
CB750 K2-75 stock looking project started 2017

Offline Justin

  • Enthusiast
  • **
  • Posts: 160
    • Cj's Garage
Re: Engine Bearing Replacement
« Reply #48 on: June 02, 2015, 10:08:32 pm »
My understanding is that none of the bearings are different unless you have a CB750A (Hondamatic automatic transmission) which I think has an extra bearing. Don't quote me on that last bit though.

I know from Hondaman's book that at least the final drive bearing was different between models, although I think his book also states that they're interchangeable..

See service Bulletine from Honda
Russ Collins used a double row bearing in their Cobra build.

PeWe, where are you getting the copies of the service bulletins? I thought that they were available on sohc4.net but I think the links were bad last time I checked...?

Offline Badluckhonda

  • Full Member
  • *
  • Posts: 87
Re: Engine Bearing Replacement
« Reply #49 on: June 03, 2015, 03:00:08 am »
So if you get these bearing from a bearing dealer you have to have grooves cut into them for the half moon clips ?

 

;