John Deere 2 Cylinder Cam Bearing Question

forty40

Member
On a JD A, does the camshaft bearing on the flywheel side absolutely need to be a press fit on the camshaft?

The race is pressed into the cap which would be the same application as with any wheel bearing where the bearing itself slides easily on the axle pin and the race presses into the hub. In stock cars, axle rpm is quite a bit higher than JD 2 cylinder rpm and we often slide into the turn at over a 100 mph and never have wheel bearing failure.

The clutch side can be understood why it is pressed on the cam because the race just slides into the case.

What kind of disaster awaits if the flywheel side of the cam is polished for a .0005 sliding fit? Inexperience makes me fearful of polishing the shaft down because camshaft replacement is a whole lot of work.

It would sure make assembly and disassembly easier if the bearing were a thumb press on the cam.
 
(quoted from post at 07:59:49 01/20/13) On a JD A, does the camshaft bearing on the flywheel side absolutely need to be a press fit on the camshaft?

The race is pressed into the cap which would be the same application as with any wheel bearing where the bearing itself slides easily on the axle pin and the race presses into the hub. In stock cars, axle rpm is quite a bit higher than JD 2 cylinder rpm and we often slide into the turn at over a 100 mph and never have wheel bearing failure.

The clutch side can be understood why it is pressed on the cam because the race just slides into the case.

What kind of disaster awaits if the flywheel side of the cam is polished for a .0005 sliding fit? Inexperience makes me fearful of polishing the shaft down because camshaft replacement is a whole lot of work.

It would sure make assembly and disassembly easier if the bearing were a thumb press on the cam.


The hub on a stock car is also held in place where as the cam only has spring pressure on it.

I'm sure it will be fine as long as your not running over stock rpms. And if it breaks it breaks, it's not that hard to get the cam out.
 
(quoted from post at 09:35:03 01/20/13) You've obviously never removed one before? Its a ton of
work. And gaskets.

You obviously don't work on many 2 bangers, I can do it blindfolded. I guess what I consider not that bad may be hard work for some people....
 
I dont think it would hurt any. But from experience and
countless overhauls, parting outs, and so on. . .the cam is
quite possibly the biggest PIA part to deal with on a 2 cyl. Its
not easy to get at, I dont care who you are.
 
I'm not saying its like changing a tire but I just don't think its all that bad, although because of what it does take to change it is on of the reasons I'm going to an OHC on my G.

Again, not saying its hardjst time consuming.
 
I would say yes, you want it tight. You dont want the shaft to spin in the bearing.
If it gets loose and spins you will be replacing the cam.
Thats why there is a bearing. On the B's there is no bearing, but has a oil line going to each one.
 
its got to b tight...if cam slides over at all to clutch slide bearing will walk right off it...only thing putting pressure on it is spring on clutch side..cam isnt back to change...if blocks out that is..there isnt a whole of room to work with block in
 
(quoted from post at 14:01:05 01/20/13) I am interested now. An OHC on a G?
Whats that entail?

A lot, kinda....

Build a drive system without a shaft or anything that does not block the swing of the crank, cam is chain driven from a sproket behind the flywheel, cam is above the valves with bcket tappets.

Eliminates cam and pushrod flex and rocker arm breakage. I was running 2000 before and plan to run a lot faster with this setup.
 
That is awesome id love to look at it :) someone needs to
make billet cranks & a 4-valve head so you can run 3-4000
rpm & stomp the red crowd in open classes!
 
They make billet cranks but I'm waiting for someone to actually run one at high rpms to see how it holds. I don't want to spend over 6k and be the first one to break one :lol:


At 578 cubes spinning 1800-2250 and running 128 octane fuel there was pretty much no red tractor that I could not beat, I even outpulled a Super M with a turbo!

The trouble came from the Minnie Mo's, I could beat most of them and get within a few feet of the rest. I did outpull a couple of them that I always thought were pretty hot.

The 4 valve head has been on my mind for a while and it will be a someday deal. You don't wanna change too much stuff at once or you will never get it to run right :D I really think I have a goo shot at running 35-4000 with a 2 valve head thats flowed correctly.
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top