TO30 rocker arms breaking

[tuffy smith]

I have a TO 30 Massey Ferguson and it keeps breaking rocker arms. I have replaced them twice and checked to make sure they were getting oil which they were. The oil prssure is 38-40 psi. Any ideas?

 

[Jerry/MT]

That"s pretty high pressure for a TO-30. The oil pressure should be 25-30 psi and should stay that way through out the rpm range. Since you say you have oil at the top end, I suspect that there are two different problems and thy may not be related. I suspect you have a stuck oil pressure relief valve that"s causing the high oil pressure. it could be reducing the oil flow to the top end but you say you have oiling there. It doesn" take much.

breaking your rocker arms may be caused your valve clearances are set too tight. I would think the push rods were the "weak link" in the valve train but maybe the rockers are. I would think that the push rods would bend before the rockers break. How are the rockers failing? can you describe where the break is at? Or show a picture ? Is there evidence of an oil related failure( "scratches" siezing, on the rocker bushings, etc.)?

 

[tuffy]

The rocker arms are breaking at the end that pushes the valve there were a couple of push rods that were slightly bent

 

[Jerry/MT]

It sounds like your valves may be or have been stuck. Witht he valve cover off, crank the engine and see if the valves are stuck. Is the engine hard to start, or if it starts, does it run like a three legged dog? Could be sticky valves.
Brake cleaner sprayed down thevalve stem will help clean them up but may eat up the intake stem seals. My old neighbor used a pint of ATF in a full tank of gas to keep his 9N valves from sticking. Marvel Mystery oil can slo be used.

You"ll also need to replace your bent push rods and that"s a tougher thing to do. You might have to try and straighten the old ones because replacements are hard to find. www.montesequipment.com may be able to help you there.