48 jd A Bad Vibration

[Adam T]

i have a 48 A that i recently restored that has a bad vibration. when you rev the tractor all the way its so bad that the steering shaft wobbles side to side. i have almost come to the conclusion that it has somthing to do with either the flywheel or the clutch driver. i was looking at another 48 or 49 A today and noticed that the weights on the flywheel and clutch driver were oppisite of each other if one was up then the other was down and visa versa and the i got to looking on my tractor and the weight on the flywheel was at 12 o'clock and the clutch driver was at about 7 o'clock. another thing that i noticed was that on the tractor i looked at the pin in the crank shaft for steering wheel starting and the bolts on the flywheel were paralel and my tractor was the same i dont know if that has anything to do with it or not. both ends of the crankshaft on my tractor have a bunch of hash marks on them so its kind of hard to tell where its exactly suposed to go if any one has any advise on how to know where exactly they go it would be muchly apreciated

 

[730-LP]

To see if the flywheel is correct remove the flywheel cover,take the left spark plug out and turn the flywheel till the piston is all the way to the front.then look at the intake impulse mark,it should line up withe the mark on the transmission case behind the flywheel.Mark on flywheel will be at 3 o'clock,If thats correct remove the clutch driver and turn till the weight is oppsite the one one the flywheel

 

[Anonymous-0]

do you people know what the " V" mark is for on the crank?

 

[John T]

If EITHER the Flywheel OR Clutch Drive Disk are out of time ITS VIBRATION CITY. Their heavy offset counterweights need to be 180 opposite.

If you can get the left piston up to dead TDC (maybe a wire etc in the plug hole) ifffffffff the flywheel is on the correct crank spline the Left Hand Impulse timing mark on the flywheel will be lined up with the timing mark on side of tractor in the 3 o clock position and thats also when the slot in the flywheel is flat horizontal fore n aft. At that same position the clutch drive disk weight will be just 180 oppoSITE FROM WHERE the one is on flywheel. Also look for V marks on the drive disk that line up with similar on the crankshaft.

Also when the left side crank throw is all the way forward (piston at TDC) thats when the flywheels weight is all the way back I believe

John T
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[Adam T]

if i could see the "v" mark on the crank shaft do you realy think i would be askin for help

 

[primerk5]

(quoted from post at 17:51:46 03/05/10) do you people know what the " V" mark is for on the crank?

My 48 A didn't have a V mark on the crank either. There was a notch cut into the one of the splines on the crank shaft for a rivit that was in the original drive disk to fit. As stated, basically the weight on the Drive disk should be opposite from the flywheel weight.

Good luck..