With that out of the way, the whole big end assembly was easily pulled out. The book states to clean it with a petrol / paraffin mix but as I didn't have any paraffin, I cleaned out an old oil container and used that as a basin, before swishing some petrol over it. Other than a few little bits of rust and stuff, it all seems ok. Dosed it up with a liberal amount of nice clean fresh oil and wrapped the big end do-dah up in a clean plakky bag and put it on the shelf for safe keeping. After that I used a rag soaked in petrol to scrub away at the old gasket goo on the edge of the case. Ok, I might have used a penknife too, but I was very careful.
The oil return pipe seems to have snapped the small clip that holds it in place, and tell me something, why does the pipe have a split pin through the end of it? To regulate the amount of oil, maybe? What should the next job? I intended to leave the gearbox alone as to my novice eye it all looks ok in there, although that seal at the back might need to be replaced. What about the left main bearing that isn't a bearing, it's a bush, should I replace that as a matter of course? The colouring looks a bit 'odd', kind of worn in patches. Is it easy to get it out? Actually, how does one remove said bush?UPDATE - just checked the bush again, one of the edges is chipped and broken so I guess it's gotta be tackled.
14 comments:
Great work GBC! You've got on with stripping Terry much quicker than I thought you would.
To scape old gasket material, make a scraper from Perspex or an old plastic ruler. File the edge to 45 degrees and it'll slice old gasket off easily. If it wears, just refile it.
Does Terry's crank have 'sludge traps'? If so, now's the time to clean them out.
Next job is to clean everything with your soda blaster (don't tell us you haven't made one yet!)
U N
At this rate we should see terry on the road soon, making it's way to ingilston next month.
Go GBC. That bushing might just need a light cleaning, if it's still round and clearances are ok. Removal and replacement can be a bit of a bother sometimes. And then the new one might need to be reamed to the proper size and all. Seems that Rick P. fella that works at that other mag was talking about bushes a few whiles back. Sometimes a large pipe tap can be threaded in and used to remove a bush, usually some gentle heating involved. My experiences have been with bikes other than "Terriors". Your Cub brothers can probably give you the best advice here. Yeah, what is that cotter pin in there for? Hairy Larry P.S. Acetone can work wonders on gaskets, let them soak a while. (using all saftey precautions as usual...)
oh yeah, Acetone might melt your plastic solvent containor and that plastic scraper you just made...might need a metal pan. HL
I love it when you produce these engine internals pictures!
What's that "Hmmm?" photo all about? A map of the Shetland Isles? Your fortune in tea leaves? (Yes I know it's debris lol)
I don't know about Terriers but could the split pin in the oil scavenge pipe be to restrain one end of a spring - the other end pushes a circular filter down against the sump cap?
Graham B
Seeing how you've got it apart, you might as well replace the seal at the back of the tranny, along with any others you see to be on the safe side.
Use a plastic putty knife or similar to scrape the gaskets off so you don't score the mating faces. Acetone like HL says should be good, it takes off mail polish it can soften up old gaskets, etc.
As UN says, if it has a sludge trap, clean it out now while you've got it apart. better to be safe than sorry later.
Personally, I'd have the gearbox apart. I doubt it is much more complex than a bantam, and you'll be amazed how much crap comes out. Bearings will doubtless be shot too, if there is any rust on them then definately. Might be extra ballache and expense, but it'll be worse to have to strip it all again! On a similar note, might be worth having the crank rebuilt too, going by the rusty sludge that was in there.
Good progress GBC. I agree with Phill.
I always used to make scrapers from cassette cases, then it was CD cases, now it's DVD's - ah, progress!
ng :)
Let's see NG, giving your age away a little there. At least you didn't say you made them out of 8-track cartridge plastic.... HL
My guess would be that the split pin is there to stop the washer and filter gauze to ride up the tube.
A sloppy small ends makes a heck of a racket but it's not really a DIY job unless you have access to a press, a lathe (to make tooling) and the correct reamers. I'd first let it soak a bit in 35% acetic acid to remove the oxides and then check the fit of the gudgeon pin.
I'm not sure if the cub has a sludgetrap but if it lives under a blanking plug in one of the flywheels, sometimes hard to remove but it should be done.
Very interesting project you've got there, it looks kinda unmollested, like it has just been dismantled and put away for a long time.
HL - my older brother got all the 8 tracks ...... Dad still swears he used to cut down a tree and make his own .......
ng :)
I have one or two old 78rpm records if you want to keep Terry's rebuild authentic! ;-)
Testing my memory somewhat, but about 30 years ago I had an AJS 250 that needed its main bearing changing. A friend turned up a T shaped bar that fitted snugly into to bearing with the flat of the T resting on the bearing - if you get my - ho, ho, ho, drift - ho, ho, ho ...... sorry!
I applied heat - sounds like I knew what I was doing - NOT! - and whacked the drift and slowly and surely out came the bearing.
The new one had been living in the fridge and with lots of oil and a copper washer the new bearing fair slid in.
The rest of the bike rapidly fell to pieces - teach me to fit a hi-comp piston!
The joys of youth - bring on those 78 rpmers!
ng:)
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