SF1 gearbox inner cover fitting issues

C

coventrykid

Junior member
Hi all
Got to fitting my new old stock gearbox inner cover and have the following problems.
First when offered up it rocks slightly as though it is catching on the crankcase face, this looked like a rough spot on the crankcase face above the oil tight area. Cleaned the area on the cover not the case and it seemed to offer up a lot better. 
Second when I tried to locate the shaft that engages with the gear selector cog all seemed well loose but got tight when I pulled the case in carefully.
Is there a trick to this as the gears select well when rotating the selector gear but several attempts have not found the spot, it is as though the cover is moving out of a good line up as pulled in.
Thanks a frustrated Coventrykid 
 
There is no trick to it. Are you sure that the clutch pushrod is locating properly into the release mechanism in your cover, no bent clutch pushrod or anything? There should be play in the clutch release arm when the case is fully home, best done without the cable attached in case it has insufficient freeplay. You must be able to check with a straight edge if there is a problem with the mating surfaces. The only problems I am familiar with there is ensuring that you maintain backlash in the two meshed gears for the selectors (in the cover) to the shift plate (in the gearbox) as if tight it can make gear selection difficult. Also adjusting your eccentric adjuster can be fiddly.
 
Thanks for the help I have taken out the pushrod and rolled it its good, the cover I checked already but have not checked the crankcase face although it looks good with no injuries.
Would it help to take out the push rod and see if they mate up clean?
Thanks again
 
Think it could be worth getting as much as you can out of the way, inside the cover, for a test fit. At least that way you have removed as many variables as you can.  Then, if it mates ok, you can introduce items until you find the guilty one....
 
Kid, as Tippie says, did you try a straight edge on each of the mating surfaces to see which one isn't flat? The outer covers are pretty substantial but I suppose yours could have got a bit bent somehow in over 30 years. The inner gearbox cover on a lot of triples (that's what you have, right?) can sometimes get a horrendous whack if the original 630 chain lets go at speed, has happened on many bikes  :-X. There's usually all sorts of damage visible inside the inner cover and the crankcases themselves when this happens (currently waiting on the machine shop to get around to welding mine ::)), but I've never heard of a damaged and repaired to oil tight inner cover still having a warped outer cover mating surface.
Inspection and straight edge should eliminate this possibility. Are you sure you have the gearshift return spring mounted properly, with the arms parallel? There should be a shim washer between the outside of the spring and the inside of the case, mine at least is quite thin, only 1 mm. Is the rivet holding the shifter arm (with the 2 little fingers) to the gear change spindle selector fork still tight? And are you using the right gasket between the outer and inner covers, it should be a thick fibre gasket about 3 mm thick.

Ken
 
Thanks I have a standard gasket about 1mm thick also the shim I did not have fitted.
I will try again and get back.
Many thanks Covkid
 
Hi all
Tried the mating surfaces all good to me with a straight edge but did the strip out of parts first and it looks like a slight rock on the upper front joint (not oil tight area but above). A friend who is a retired engineer said we will try marking blue to show first touch then proceed, he thinks the same as poffer it will show as you go but he needs a magnifying glass due to the eyes these days!
So far the push rod and other components look good so could be that where the non oil tight surfaces get close it could be a rough edge there are a few but not even a bit of damage in the sprocket area? This seems strange cleaning mating surfaces (non oil tight) to get a good fit, my previous steeds have been mostly Morini with no issues of this type forgoing the bloody crap exhaust collars so the old adage if you take it off you cannot put it back on looms large.
My thoughts on the non oil tight surfaces say that they must be correct and the rougher non oil tight areas just need to pull in clean to resolve this I am just reluctant to go that far.
Have another look in the morning, the build is very near and I should get some pictures up as its looking really good to me anyway.
Thanks for the help so far Covkid
ps Gavin Spencer did a great job on the clocks...
 
Kid,

I've come across several warped gearbox covers, not much you can do about it bar replacing.  Just nip it up with the lower screws first and all should be OK, it is quite pliable in the upper portion.  Does put a bit of strain in the cover casting, but so far I haven't witnessed any cracking up resulting of this.

piet
 
hi , you have mentioned you have a standard gasket , i had a similar problem but it was leaking oil on off on off did my head in ??? then i rang Richard salter who straight away said i had purchased a cheap gasket from the internet well his exact words were you've brough them bloody cheap Indian gaskets. next day new gasket from Richard problem solved  :D :D
good luck and safe riding Andy
 
your quite right dick, nasty little typo i have gone to the back of the class for 30 mins and have promised never to do it again. :o :o :o.
humbly yours andy
 
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