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I have a 67 T120R. The clutch pushrod bushing is worn and needs replaced. Any ideas on how to get it out of the main shaft? I have a feeling I need to open the primary and remove the clutch in order to take the transmission apart. Haven't quite gotten to that point yet. The part I'm referring to is number 2 here:
http://www.mapcycle.com/parts-fiche...x-shafts-gears-gearbox-shafts-gears.html

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Out of curiosity how have you determined thE bushing is wore out? That would normally be something some one would discover because they disassembled the transmission for other reasons. To answer your question the primary case and outside transmission case need to be removed. The clutch pressure plate needs to be removed and a drift/rod inserted in the hole in the main shaft and drive the bushing out towards the right side of the bike.

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Found metal in the oil. Decided to go hunting. Found the busing to be loose and out of round. Think tapping it and trying to pull out with a bolt and heat would work? Trying to avoid going into the clutch.

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Are you planning on replacing the bush on the right also? I do not see why you would push the bushing all the way through the mainshaft when you need just as long a drift to push it out the left and shorter distance.
You will have to remove the pressure plate to get to the mainshaft and the outer gearbox cover to get to the mainshaft on that side.

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Hi ArmyMutt, Yes, you are on track. Tapping to a suitable size bolt is what I'd recommend.

Leave primary side alone. Remove rod adjuster cover on primary & remove rod adjuster screw with nut.

Remove right trans outer cover. Remove clutch rod.

Tap bushing. Size will depend on wear. 7mm can work if not too worn, 5/16- 18 tap is probably what you'll need. Threaded rod is easy to get in that size as well as is longer all-thread bolts. Ace Hardware.

OD of bushing is aprox. .400" bore in bushing is aprox. 7/32" .219". The used bushing in main shaft on my lap bore is .220".

Place tube or socket on end of main shaft resting it on side of nut. Place suitable flat washers over end of tube. Screw it bolt with lots of threads or threaded rod & nut. rod. This will be extractor. Tighten bolt or nut & it will pull bushing. Tube or socket has to be large & deep enough for bushing to freely fit into.


Main shaft is hollowed out for bushing aprox. 6-7" deep. Clean the hollow area of metal chips.

For installing you can simply drive in or I like #12 bolt with no threads near head (hard to find), or 5mm (Ace hardware has) with no threads near head. Use flat washer on bolt. Grease hole in shaft & outside of bushing. Drive bushing in flush. Use 7/32 drill bit by hand on end of bushing if bore is reduced from driving. Take new bushing to hardware store & fit the driving in bolt to bushing. A free sliding fit.

I've wanted to try pulling in new bushing with #12 threaded rod, but haven't done it so far. threaded rod all the way through with nuts on both ends. Just a thought.

Sometimes rod will wear at the shoulder of hollow part in main shaft. About 4-7/16" from left end of rod. Best to replace rod if worn there.

Rod is often slightly smaller than 7/32. The rod on my lap is actually .216" diameter on the unworn part.

Verify main shaft nut is indeed tight. Always bend both tabs around nut. Factory often did only one.

Look at bushing & how much metal is missing. Are you sure the chips are from clutch rod bushing?

Don


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HI, You can't push bushing out from left end of main shaft. The bore in main shaft is OD of bushing about 6-7" from right, & is a little larger than 7/32 on left for about 4-7/16". This makes drifting bushing out from left difficult. So there is a large hollow area inside main shaft behind bushing, but back side of bushing is hard to access in practical terms the way I see it.

If you tapped bushing & put bolt in it, you could drift it out from left, but drawing out with puller bolt is easy.
Don


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You could, at a push, drive the worn bush further in and fit a new bush in the vacant space. If the original is worn its doing nothing anyway.


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I ended up tapping it for 5/16" rod. Put on a nut and a single washer to get things started. Heated it up for good measure and started tightening the nut. Added a few washers at a time, and it's out. I flushed the hole with carb cleaner. Looks clean with a flashlight. New one is on order. I think I might put it in a freezer overnight and heat the shaft up when it's time to install it. I'll look for a suitable bolt in the meantime.

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Hi ArmyMutt, Good!
How tight did bushing seem to be in shaft?
How was clutch rod?
Sounds like you have a plan.
Might want to put torque wrench on main shaft nut. These really like to work loose. Good plan to have spare lock tab on hand should you need one.
This nut red Loctite is not bad idea. Use heat gun to remove later. Usually unscrews cold even with red.
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I always slip something slightly bigger than the hole in the bush into the shaft (ball, screw, anything) so it rests against the bush, and use the pushrod to tap it out. Unless it's worn real bad one may have to tap for a screw I guess, but these bushes usually come out easy.
I simply tap the new bush in with a hammer, never thought about it much, just did it. I stick a bolt into the bush and tap against the head, so I do take some care...

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It was in there tight enough to require some muscle on the wrench. Once I got it out about 1/4 of the way, finger pressure was enough. My mainshaft nut was lose, but I assume that's what the lock tab washer is for. The Low Brow Customs video showed Todd just unscrewing it with his fingers after bend back the tab, so I assumed this was normal. If I'm off Friday, I'll try to find an Ace hardware.

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Hi ArmyMutt, Trust me, the loose nut is common, but certainly not "normal". They are not suppose to come loose, but do, thus the need for Loctite & tab.

Any local hardware store should have what you need. I like Loctite red 271. Hardware store almost always stocks the little tube.

Be sure to use torque wrench on this nut. No guessing!!

Put in 4th gear. Hold brake tight & torque. May need assistant for brake, but usually you can set on seat, hold brake & torque.

In the mean time, remove nut, gear, spring, sleeve, washer. Gears usually don't wear much. Sleeve can wear on end & groove washer. Washer is behind sleeve against ball bearing. If sleeve spins from loose nut it wears washer & sleeve end. If installed worn the mating surface is compromised & I feel it doesn't support as well possibly promoting loosening of nut easier.

Spring can wear at ends & fracture any place. A flat coil spring.

torque for kick start pinion (main shaft) nut is 45 ft #.

If brake won't hold tight enough, but it should.

If not, I feel easier to thread chain whip tool in with bike's chain & hold from the trans sprocket. I've done that & works really well. Fiddly to do but easier than taking primary & clutch plates out to hold with clutch holding tool. Easy to make with 1/2" steel pipe & old chain.
Don


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I find loose mainshaft nuts all too frequently, but as Don says it's not "normal" in the sense that it's the way it should be.
Personally I don't use tab washers, they're soft and I feel they may contribute to loosening the nuts as the soft steel is deformed over time. Remember there's a lot of forces being fed through this shaft, twisting, bending and shock loads. I use some kind of reputable thread locking compound on the nut and do it up very tight, 60 lbft or up to 70 even. I use less torque on the other end of the shaft, 50 lbft or so as I don't want to break anything.
I have never had any of these nuts loosening on me, but often find that it takes less effort to undo them than what I applied when I did them up.
Lastly, I don't keep a stock of different locking fluids, so I use what I have. If that's Loctite 638 (green stuff, seriously strong) I may use a propane torch before I undo a nut. Open flames and motorcycles don't really belong together, so I'm extremely careful and have an extinguisher at hand at all times.

To hold back I have the age old tool which consists of a driven and a driving plate loosely bolted together (easier to insert if a bit loose) with a solid handle on it. I let the handle rest against a foot rest, or a screwdriver stuck into a hole somewhere, you'll figure out what suits your application.
If doing the RH side nut only, Don has it covered, and Loctite 271 is very strong.

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There is an important exception to using 45 foot pounds on the 5 speed 57-7077 kick starter side main shaft nut. This is with the after market replacement mainshaft with the larger 5/8" threads. For some unknown reason the root of the threads extend very close to the counter bore that holds the clutch rod bushing on the kick starter end. At 45 pounds the shaft can break at the threads. This only refers to the after market 57-7077 mainshaft with the 5/8"-18 threads. I have found 30 pounds, lock tab and Blue Loctite work just fine on this part.

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Hi John, Thank you very much for pointing that out! Important thing to know!
Don


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