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Slash 5 Flywheel removal

kwb210

New member
The bike: 1972 R75/5 about 55,000 miles, parked for many many years, getting a once over before moving to the category of "rider". I'm pulling the flywheel to inspect and replace the rear main seal as well as the oil pump O ring. Removed the 5 bolts in flywheel and she is stuck! I don't want to use a puller as that might push the crank forward, it is blocked but does not seem worth the risk. I thought of using a dead blow hammer attached to a bolt screwed into the wheel. So, I am looking for suggestions on the safe removal of the flywheel.
Thanks!
Kurt
 

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heat with a torch is a pretty standard method and then it pretty much pulls right off......The same thing for re-install........God bless......Dennis
 
Flywheel removal

I use a piece of 1/4 in. bar stock that's long enough to cross the bell housing. Drill a couple holes opposite holes that hold on the clutch assembly, and use two of the clutch removal bolts to pull it off. Don't need heat, just patience.
 
Sucess!

Used the combo of your statements to release the flywheel (with no damage to any surrounding parts or humans). Finally was able to use my 18mm Craftsman combination wrench, it has hung up for years and never got any action, living between the highly used 17mm and sometimes used 19mm, it was a forgotten wrench. Used the clutch removal bolts to hold the 18mm across the flywheel, then a bit of heat, not too much, and a dead blow hammer attached to the 18mm wrench, a couple of hard hits on the dead blow shaft and the flywheel pulled loose. Not much oil leakage. After 40 years I would expect the seal to be nearing the end of it's job of keeping oil on the inside! Any bike that has low miles typically has sat for extended periods and that allows the seal to dry out, that spells leak. The seal is not cheap, about $26 bucks, but why risk a mess on your clutch plate? I see these really nice looking bikes with low miles go for fairly high sums and note in the descriptions all the seller did was freshen up the fluids and gosh, it runs great! Just wait. While the job is a bit labor intensive, it is rewarding. Plus you have the chance to clean stuff up like the swingarm bearings.
Next step is a lightened flywheel!
Kurt
 

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Lightened Flywheel

I have a slash flywheel already machined and ready to install, I am also doing a 1974 R90/6 so I had the machine shop do the same on that wheel. They look pretty cool.
Kurt
 

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Cleaned her up a bit

I was lucky that the grease was fairly light, a scotch brite pad and cleaning solution made fairly quite work of it. Seal came out and now I will sit and look for the Postman to come down the street with my new rear main seal, oil pump O ring, flywheel bolts and clutch cover allens. I order stuff from Hucky's and he is really quick about getting stuff out. So while I am waiting I will pull the seals from the swingarm and clean and re-grease the swingarm bearings then install new grease seals. Fun stuff!:brad
 

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So while I am waiting I will pull the seals from the swingarm and clean and re-grease the swingarm bearings then install new grease seals.

What seals are you referring to? On my /7, there's a plastic cover that pops off. Possibly on the earlier models there as a hex cap nut that just screws off. Using one of a variety of rubber coned devices (like for lubing chainsaws) you can put that in the center of the bearing and push grease through to the other side. Basically, the bad stuff gets in from the back side...by pushing that way, you just push the old grease out to the gap in the swingarm where it can be cleaned up. For a thorough cleaning, you must by the right tool to actually pull the bearings and races.
 
Seal: outer seal to keep junk out

Okay, not a very good description...I believe slash 5 from 1970 and bikes clear up to about 1985 used the same format. In a perfect world where the swingarm was greased/serviced on a regular basis you could just continue the regular service like you described. On bikes that sat around or were not greased on a regualr basis the grease gets hard. When you attempt to insert the grease tool to send in that shot of fresh grease the old stuff does not want to move. So I pul the swingarm seal, 31 41 2 000 331, which destroys it, and then pull the bearing out. The bearing is usually not worn much, clean it and fill it with wheel bearing grease, clean out the housing and re-insert the bearing into it's race. New swingarm seal and you are back in business! Here is a pic of what most of us would see when we started. I have removed the spacer at this point.
 

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Cycleworks tool: swingarm bearing puller 1955-1984

What a range of years the tool works in, wow. Sweet tool that does not damage the swingarm. The brass colored nut in the middle is pushed down and the Allen screws expand to grab hold of either the seal or the bearing race.
 

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seal is out, ruined but that's the way of life

The seal is now out, destroyed but no damage to the swingarm or the bearing.
 

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Bearing unharmed

The bearing is out and can be cleaned. Roll it around in the race and make sure there is no resistance.
 

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Clean out the housing

Clean out the old grease from the housing. Add new slightly less smelly grease to the housing and add the newly greased used bearing to it's race, try and keep the right side on the right side and the left side, well, you get it. Now the swingarm is set for another life as long as you service it. New grease and the bearing is set to do it's job no matter what the load...
 

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Now here is a load I had not thought of

probably not over-loaded considering the German engineers and what they had in mind, or did not have in mind. :scratch
 

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Finish the job w a few more posts

I started with just a question but suddenly here i am finishing my project on the forum.
I have a rear main seal installer that works beyond perfect! Once you have cleaned the surface where the seal will go apply some gasket stuff, I usually use Yamabond, let the seal sit for a minute after the Yamabond is applied, press it up against the engine just enough to hold itself in place, then place the seal installer against it and thread in the flywheel bolts. THen it is just a matter of going around in circles ( I am especially good at this) and throwing a turn or two on each bolt. Soon the seal installer bottoms out and the seal is in place with no damage!
 

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new rear main seal in place

there she is, living happily there after doing her job if applied properly, lots of leaning towards the word properly, otherwise a big mess on your clutch disk.
 

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Next; a fancy new flywheel

Oh boy, now I get to install the lightened flywheel. a little engine oil on the part that rests on the seal and push it in til you hit bottom, yup, I mean that. Then do the torque settings etc using something like I did to hold the wheel from turning.
 

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Clutch cleanup

Clean up the clutch assembly with some brake cleaner so as not to leave any stuff on the surface.
 

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