Honda-SOHC

Other Stuff => Tricks & Tips => Topic started by: MrBoo on February 08, 2021, 10:17:32 AM

Title: changing bearings in aluminium housings
Post by: MrBoo on February 08, 2021, 10:17:32 AM
I own a 1964 CB72.  The Honda workshop manual shows a method for removing the camshaft from the cylinder head: take a plastic hammer and a drift and hit the outer race of the camshaft bearings.  I did this as a teenager and the method is likely to damage the bearings.  Much better to warm the cylinder head with a hair dryer for 10 to 15 minutes.  Differential thermal expansion allows the steel bearing races to slide easily in the aluminium housings.  That is, the aluminium housing expands more than the steel bearing when heated.  50 to 60 degrees centigrade is usually enough to allow the bearings to slide while not being too hot to hold.
Title: Re: changing bearings in aluminium housings
Post by: AshimotoK0 on February 08, 2021, 10:33:47 AM
Please introduce yourself Mr. Boo .. as I have a UK '64 CB72 I am restoring and always good to compare notes.

Some literature here which I scanned and are also in  my Dropbox links on here (along with other bike literature)

CB77 Service Manual:
https://www.dropbox.com/s/vs8c1fke3tcohpv/honda-shop-manual-CB77-superhawk.pdf?dl=0

1962 CB72 MCM review
https://www.dropbox.com/sh/1ly92qmzivx1ina/AAD4TwKvGkiEs14baZ_2krIGa?dl=0

CB72/77 Green v 2 Parts Book
https://www.dropbox.com/s/92db91hr189sazi/CB72_77%20Parts%20Book_2.pdf?dl=0

CB77 Parts Manual

https://www.dropbox.com/s/bwa12mrrriberq6/partslist_cb77_170513_0708.pdf?dl=0
Title: Re: changing bearings in aluminium housings
Post by: Laverda Dave on February 08, 2021, 08:49:18 PM
I agree Mr Boo. I've just had to remove the countershaft bearing from the Z400J engine. I wasn't going to chance tapping it out especially as I need to reuse it. I used the electric paint gun around the area and it just fell out!
Title: Re: changing bearings in aluminium housings
Post by: K2-K6 on February 09, 2021, 12:28:56 AM
For bearing removal

[attachimg=1]

Quite a neat concept and not too hard to make, possibly.

Title: Re: changing bearings in aluminium housings
Post by: K2-K6 on February 09, 2021, 07:57:24 AM
Good idea that. Would be even better with a screw one slide hammer for blind bearings.

EBay? K2

Yes, they use a small slide hammer on them. This source is specifically from Commencal MTB company for pulling bearings on rear suspension links etc like this picture of a rising rate shock linkage.  Similar in restrictions to some of the SOHC situations, these are paired and so difficult to get to the back of them.

 [attachimg=1]

Neat bit of thinking though.

Title: Re: changing bearings in aluminium housings
Post by: K2-K6 on February 09, 2021, 08:25:09 AM
I hadn't thought about it before,  but these are like a collet chuck in a lathe or mill tool chuck, but in reverse.

https://www.endurobearings.com/products/tools/bbt-200/ some bicycle tools are hellish expensive though  :o

[attachimg=1]

From above link, nicely made kit.


Title: Re: changing bearings in aluminium housings
Post by: AshimotoK0 on February 09, 2021, 10:06:23 AM
If you watch Allen Millyards's videos on You-Tube  he uses a lovely old Sykes-Pickavant bearing puller which grips the outer race. Also videos on Youtube using mashed up white bread stuffed in the bearing to extract bearings that are in blind holes (hydraulic action)
Title: Re: changing bearings in aluminium housings
Post by: Trigger on February 09, 2021, 12:12:30 PM
Never used one in all my time. Easy to put the part in the oven and once hot, tap the case down on a oak block  ;)
Title: Re: changing bearings in aluminium housings
Post by: paul G on February 09, 2021, 12:20:08 PM
Never used one in all my time. Easy to put the part in the oven and once hot, tap the case down on a oak block  ;)
Would Pine do  ;D ;)
Title: Re: changing bearings in aluminium housings
Post by: MrDavo on February 09, 2021, 12:29:02 PM
Quote
mashed up white bread stuffed in the bearing to extract bearings that are in blind holes (hydraulic action)

I wonder who first thought of stuffing his sandwich into a blind bearing?
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