Tue Nov 27, 2012 9:15 am
I pulled the front off my cub and engine after my hyd pump broke and found lots of metal in the oil pan. I also found that my cam gear is missing teeth on the back side. lucky for me I have a spare cam and gear. I pulled the gear from the old cam with no problems. Now to pull the gear from the one on my motor. Has any one done this with out pulling the motor I tried a 3 jaw puller but can't get a bit on inside lip. If anyone has any suggestion please let me know.
Tue Nov 27, 2012 10:50 am
the only way to change the cam gear is to remove the cam from the engine. It is a pressed fit and will need pressed on. pressing it on the cam while in the engine will result in oil pump damage
Tue Nov 27, 2012 1:01 pm
I have always installed interference fits by heating to 400*-450* F then it should slip right on by hand. Heat it evenly around the outside while pulling to remover the old one. heat applied to the outside will make the gear "grow outward". if the whole gear gets too hot and starts to soak into the cam let it cool off then try again. to install put new gear in the kitchen oven for 20-30 minutes. Never done a cub cam gear before but lots of other interference fits in gearboxes this way. By the way 450* is hotter than you think when you see it in real life.
Tue Nov 27, 2012 10:13 pm
Gives me some ideas. I thought about using a dremel and cutting the gear off. I'll try the heat first and if get it off then I'll try the same to get it back on. Does the cam have a threaded hole? If so I could press the cam back on with the impact and plate of steel. and if all fails I'll pull the motor and cam.
Tue Nov 27, 2012 10:20 pm
I think I would take Clark's advice
Tue Nov 27, 2012 10:45 pm
jim turner wrote:
I think I would take Clark's advice
Ditto. Take the time to pull the engine and remove the cam shaft. Just time, not as expensive as messing up something like the oil pump.
Tue Nov 27, 2012 11:01 pm
I changed a cam a while back, not that big a deal. of course you have to pull engine and remove flywheel to get the Woodruff key out of back end of cam shaft. Took some wedges like used for shimming doors and windows, and cut a slot in the center. Turned crankshaft and as each valve came up I drove wedge under it to hold valve up, then rolled block over so the followers were clear of camshaft and removed it. Put new cam in, removed wedges and adjusted valves.
Tue Nov 27, 2012 11:07 pm
No threaded hole on that shaft..... Just setting here thinking about ways to do this and I can't see it being done with out removing the engine.
Can't drive that gear on without possibly damaging the back where the oil pump sits. Could even crack the cast block on the back side pump area.
The valves will need lifted to slide the cam out and clear the lifters, this will require removing the head to place wood wedges under the valves or some way to lift and hold the valves from the valve spring area.
Also need the engine up side down or on it's side to keep the lifters from falling out.....
We're just full of good news tonight.
Wed Nov 28, 2012 6:47 am
does the gear looks like http://www.tm-tractor.com/gen/camgear_001.htm
you said you can't get a bite on it with a 3 jaw puller, try useing a steering wheel puller and bolts throught the spokes of the gear with big washers on the backs. or you could drill and tap holes in the junk gear to thread bolts into to get a hold of it. or yes a "blue line" cut with a cut off wheel. that is hard to do without touching the shaft. but a lot of times if you just get close with a cut off wheel you can finish splitting it with a hammer and chisel driven into the wedge. be carefull cam bearings are usually super soft and impact could damage them.
Wed Nov 28, 2012 6:56 am
No cam bearings in a C60 engine.....
Getting it off will be easy, the going on part is where braking something can happen.
Wed Nov 28, 2012 10:30 am
You HAVE TO pull the camshaft out to put the new gear on. There is no point going to extremes trying to remove the old gear from the shaft while it is in place. Just take it out do it right.
I'm not sure if you have to remove the oil pump to remove the camshaft. If the rear end of the shaft is small enough where it fits into the oil pump gear, the shaft with the drive key may pull out through the rear bearing. If the oil pump gear is tight on the camshaft, you are back to the same problem, needing to remove the oil pump to put the oil pump gear back on. The tappets shouldn't be a problem with the engine still in place. Block the valves open as already described, hold each tappet up with a wooden clothes pin in from the side.
Wed Nov 28, 2012 11:15 am
Remave the engine or you will make a mess , the cam may slide out of the oil pump gear, but you will have trouble getting it back in.
Wed Nov 28, 2012 1:55 pm
Jim Becker wrote:.....
I'm not sure if you have to remove the oil pump to remove the camshaft. If the rear end of the shaft is small enough where it fits into the oil pump gear, the shaft with the drive key may pull out through the rear bearing......
There is a Woodruff (half moon ) key in the camshaft that turns the oil pump gear. That key will NOT pass through the rear hole in the block.
Wed Nov 28, 2012 7:58 pm
So bottom line is to pull the motor and pull the cam. I can't believe how much damage a little nut can cause!
Wed Nov 28, 2012 8:06 pm
gpcub wrote:So bottom line is to pull the motor and pull the cam.
Unfortunately, that is the only line. Any other way will do nothing more than cause more damage and grief.
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