Another Super video from Mike, Shttps://www.youtube.com/watch?v=YnR-9m-RMI0uper repair on Gearbox top, Wish I had done that instead of welding. Cheers Bill.
ET: Engine (Twin) Shadow Engine strip
- Thread starter Bill Thomas
- Start date
Interesting watching how some strip engines. Pretty rare to have cases that hard to separate, unless the drive side shaft is a bit snug in the outer ball bearing. Those cases look like the sealant used on the parting face was Loctite 518 .........I would not recommend the use of that product for a job like that, as by the time you get all the correct though studs in all their holes and nipped up, the sealant has gone off and will actually hold the cases apart slightly...........
I thought it was a good all round look inside , For anybody who wanted to have a go.
Not sure I like pressing on the driveshaft like that but anybody doing a big job will have to make up there own mind which way to do things.
I had a funny one sometime ago, The gears had been taken out and they put a new shim between round alloy left hand plate and main gear shaft, We could see somebody had been in there And I said to Ron , I was not happy that there was no endfloat, So I took all the gears out and found they had not found the left overs of the old shim !, All that was left was a thin round ring, Not easy to see, I would think the clutch nut had not been tight enough in the past, But with the old bit of washer and the new washer, It left no endfloat.
Cheers Bill.
Not sure I like pressing on the driveshaft like that but anybody doing a big job will have to make up there own mind which way to do things.
I had a funny one sometime ago, The gears had been taken out and they put a new shim between round alloy left hand plate and main gear shaft, We could see somebody had been in there And I said to Ron , I was not happy that there was no endfloat, So I took all the gears out and found they had not found the left overs of the old shim !, All that was left was a thin round ring, Not easy to see, I would think the clutch nut had not been tight enough in the past, But with the old bit of washer and the new washer, It left no endfloat.
Cheers Bill.
He's right about the distortion in the cases if you weld up a new gearbox spindle mounting. I've had boxes that showed little or no end float in the mainshaft, it also stops lubricating oil getting into the bushes, and destroys them too. Remember a while back we talked about how tight the clutch nut should be done up, well if it is not tight then there is how that shim becomes too thin. I always like to be able to feel some end float with the cover screws nipped up, it is all too easy to make things with too little a tolerance, but things need to move unrestricted and to cope with expansion as well.
Ron didn't want to get too involved, Should have seen his face when I pulled all the gears out !, But pulling and pushing on that shaft is something I have always done, Bit like looking in the oil tank to see oil returning, Did that on the startline at a hill climb in Devon, = Bike back on trailer for Home !!. Cheers Bill.
Like that sinking feeling you get when you offer to help some poor bugger fix their bike, only the "Can of Worms" you have exposed ends up more like eating a "Giant bowl of spaghetti".................
the knowledge of proper Enlish fails me here.....
Improper English works better sometimes
..John
I am NOT a sealant expert but I can read data sheets that Loctite have available.
Greg is correct, on Aluminium 518 starts to cure at around 8 minutes while 510 starts to cure at around 15 minutes, so 510 give longer working time. Once cured the tensile shear strength of 518 at 7.5 N/mm2 is higher than 510 at 5 N/mm2 , which means 518 is harder to disassemble than 510 once cured. I have attached a comparison chart on the cure speeds of 518 vis. 510 for those interested.
There is another grade that I have NOT used but it looks like it may be even better for our use than 510 - and that is Loctite 573. It is much slower curing than 510, with cure starting at around 3 HOURS, so we would have a lot more 'wriggle' time plus once cured it has a low tensile shear strength , just 1.3 N/mm2, so disassembly should be very easy. Only downside seems to be a long time to reach final cure, something like 72 hours on aluminium.
Martyn
Alloy engines I use threebond 1215 in grey and on shadows threebond 1207 B in black, best sealant I've used for years, leaks almost non existent. Cylinder base gaskets I use Loctite aviation 3 non hardening in a bottle with the brush on the red cap, looks like liquid tar good for use on joints that don't need to go hard, I also use this stuff in the bore and smeared around the oil pump brass sleeve on assembly, helps to seal and aids in the installation of this tricky part. I use to use Loctite 518 years ago in the automotive game, but I have found it very limiting for use on motorcycle engines, as I had a couple of instances where it started to harden too quickly before something was fully tightened up. On a twin there are a lot more through studs than on the singles, and their lengths are important and some of them will leak oil past if you don't seal them as you assemble the two case halves. On a hot summer day you need to work quickly and have everything organised before you start applying a bead of sealant to the cases, or you can run into trouble.