Re: rocker shaft 706..263

well hears the story...and I am not much of a mechanic, anyway I did a rebuild on my 706-263 and did not do cam bearing. every thing was good until I got about 50 hrs. on it then no oil to tappets. Rocker arm pretty much wore out now. So here is the question.. if I put in front cam bearing and replace rocker shat will that get me oil back to the tappets

If the #one cam bearing is the one that supplys oil to the rockers, it might help, but you need to find out just how the rockers get oiled.

i'd look for other cause, would have to be really, really worn to not pass enough oil to at least keep it going

there is an old gentleman in my area there used to work on old series like 300 & 400's and he thinks the that is the front cam bear has turned that the tappets wont get oil but he is not sure about the 706 with 263 and if that wouldn't be it I don't know where else to look . and if that would happen to be it..do I have to take the cam out to replace the bearing??

I just don't know where else to look if it is not the cam bearing. Could you sig me on to some
other place to look for the trouble

Yes. Probably not a job you should try. 1st need a tool to push them in just right size. 2nd what about cuttings. 3rd I would want engine out. And take to machine shop.

You need to find out how oil reaches the top. I bought a weak running Super M with a noisy top end a few years ago, figured it was just worn out, found no oil to rockers, supposed to go up center cam brg, block was cracked and brg. turned. Wasn't expecting that, didn't have water in oil or oil in the radiator. No idea the route the oil takes to the top of a 706.

Oil is fed through third cam bearing (might be second but think third). But, you may have mixed up the rocker arm supports and blocked the passage coming up through the head. Also, I once overhauled a C 291 and had no oil to rockers. Found out the rocker support , although in correct position was covering the feed hole. Just a very small movement to the side and it would uncover it. I wanted the rockers centered over the valve stems so I think I made a little groove in that port in the head or in the rocker support. With 50 hours and a worn out shaft you may have to pull the head because when you take all those rocker side head bolts off that head gasket is not going to like that at all, even if you drain the coolant. Usually the supports are difficult to mix up on the gas engines as some have a guide sleeve but on the diesels, you can mix them all over the place. Have seen it done and rockers really take a beating.

well now.. I have looked around the internet some for a diagram of the oil gallery on a the 263 gas engine but seem to find much. Was wondering if anyone out there ha a diagram or could explain how the oil gets to the rocker arms and tappets

One of the cam bushings in the block has two holes. (Can't remember if 2nd or 3rd) These holes need to be lined up with the two holes in the block to allow oil up to the rocker arms. (one is pressure from the oil gallery in the block, the other is up to the rockers) I had a machine shop install the cam bushings in my 560 and told them about the two holes. They only lined up one hole and when I fired it up, no oil to the rockers. Pulled the head, pulled the cam, took an extra long drill bit and drilled the bushing while still in place.

The oil from the cam bushing travels up a drilling in the block, then thru the head gasket hole, then thru a drilling in the head, then along side a rocker shaft bolt, and then thru the hollow rocker shaft to the rockers.

Always check for rocker arm oiling on the first fire up.

Another thing it could be is the plug in the outer most rocker shaft end brackets. If one is missing, the oil will simply run out the end of the rocker shaft.

Did you have the rocker shaft completely apart with the rockers and brackets off? If so, examine the middle brackets for one that is different. You may have it in the wrong place and oil cannot get up past the hole in the head mentioned above as it will be blocked by the bracket without the "oil" provision.

Head gasket not installed correctly and blocking the oil hole could also be the issue.

If this is a tractor that you have had for quite some time, it is doubtful that the cam bushing is indexed incorrectly.
If you don't know the history, then it could be the problem.

Thanks pete23.. I guess it is worth a try to pull the rocker stands and see if they could be mix up as it did come in half when I took it out earlier, but I would think I would have not lasted more than 4o hrs. or more with out lubed much or at all. But then on the other hand ,I had the rocker shaft off yesterday and put some solvent in any hole I could and put air pressure in any hole I could an had oil coming up one of the center support bolt holes about 34ths the way up the hole with about 12 min of cranking with plugs out.. so I put rocker and tappets back on and ,but still no oil to tappets..oiled then by hand of course when I had it running. it appears like oil would have to come up around some of the head bolts.. or maybe not.. that is just the way it looks to me!

thanks vics for you reply it is appreciated.

thanks a bunch Heat Houser for your input. at leas now I have a few ideaes and can continue to investigate more into the problem!!

I just looked at service manual. It is pretty sketchy but it is the second cam bushing from front that delivers oil to rockers. There is a hole in block right next to the third rocker arm shaft support from front. I don't remember if there is a corresponding hole in the head or if the oil goes up along side of the head bolt but the head gasket has a ring in it that surrounds that hole. Like I said before, I do remember that one engine that the rocker support interfered with oil supply. I had started it and ran to warm up for retorque and readjust valves and had no oil to rockers. On another note, perfect circle used to tell us you could run a car a 100 miles with no oil to rockers. They used a test procedure which varied with different models of engines to check for oil consumption through the valve guides by blocking the oil supply to rockers. I do know they run quite a while with just assembly oil but then start raising heck.

thanks Pete for the location oh the oil passage. I think it may come up around the head bolt. I'm am going out to the farm to day and take off the rocker shaft.. I will let you know what see.

To Pete 23,Vic,Heat house and everybody that jumped in and gave me some great help with the 706--263 engine not oiling the rocker arm and tappets.. What I found was one of the rocker supports was in the wrong place. The oil reaches the rocker shaft from the 3rd rocker support from the front of the engine. Thanks to all you guys for the great advice. Now I will go hunting for a used rocker assembly.