Author Topic: Gap between Gearshift Drum rollers and the End Plate - about 0.8mm ?  (Read 516 times)

Offline 400 Cafe Racer

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Just in the process of inspection prior to rebuilding the engine.

The gears were a little baulky finding neutral on a couple of occasions, all gears and selectors are good, so I have had a close look at the shift mechanism. I have managed to replicate this while the casing is open and found that there was a slight "twist" misalignment of the left leg on the positive stopper, causing it to foul (evidence of rubbing) before engaging with the roller.

I think this showed up more  because of the  extra load of lifting the neutral roller on its cam as well as the drum roller on its cam.

After realigning the left leg it operates smoothly.

However - it seems a little odd that the ends of the rollers have a gap of 0.8mm before the dished end plate - ( see photo )

It would surely be better for the rollers to almost touch the end plate - this would allow more secure area for the Rositive stopper (item 8 on diagram) legs to push against - which at the moment could be partly where the gap is.

There does not appear to be any bending of the dished washer causing the gap. Maybe this is just normal tollerances as the positve stopper legs are only steel pressings. We can get paranoid about things that will operate normally, but  are not to Rolls Royce standards.

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Is this gap normal. ?

Thanks

Dennis
« Last Edit: July 21, 2021, 08:30:59 PM by 400 Cafe Racer »
Retired Automotive Engineer   MIMI, MITRE, DMS, MCMI.

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Offline Nurse Julie

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Re: Gap between Gearshift Drum rollers and the End Plate - about 0.8mm ?
« Reply #1 on: July 20, 2021, 10:00:30 PM »
That is correct, here was my engine at that stage and the gap is similar to yours.

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Offline 400 Cafe Racer

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Re: Gap between Gearshift Drum rollers and the End Plate - about 0.8mm ?
« Reply #2 on: July 20, 2021, 10:11:52 PM »
Hi Julie,

Thanks very much for your confirmation on that point. 

After the realigning of the positive stopper I mentioned it functions smoothly, so no further action.

I will look at that bearing overhang you mentioned on Teds post, when I split the casings to fit the main bearing shells.

I would like to PM you over the next couple of days for some parts please if thats OK.

Regards

Dennis

Retired Automotive Engineer   MIMI, MITRE, DMS, MCMI.

Latest    - 1979 CB400/4  Cafe Racer - Parakeet Yellow
              - 1939 Velocette GTP 250 twin port Two stroke

1988-91 - Lamborghini Countach QV replica design and
                 build - 3000hr spare time project

In 1956 at 12yrs old and dirt tracking
              - 1937 Rudge 500 4 valve
              - 1940s Royal Enfield 225sv
              -  Ex WD Norton 500sv

Offline Nurse Julie

  • 1977 CB550/4 Mongrel Brat. 1974 UK 500/4 K1. Honda CD250u.
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Re: Gap between Gearshift Drum rollers and the End Plate - about 0.8mm ?
« Reply #3 on: July 20, 2021, 10:15:30 PM »
Yes Dennis, of course, just PM me.
LINK TO MY EBAY PAGE. As many of you know already, I give 10% discount and do post at cost to forum members if you PM me direct.
https://www.ebay.co.uk/sch/julies9731/m.html?item=165142672569&rt=nc&_trksid=p2047675.m3561.l2562

LINK TO MY CB400/4 ENGINE STRIP / ASSESSMENT AND REBUILD...NOW COMPLETE
http://www.sohc.co.uk/index.php/topic,14049.msg112691/topicseen.html#new

 

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