1066 valve adjustment problem

IH 1066 purchased a couple years ago, probably 7,000 plus hours. Noticed valve noise last year, serviced tractor and adjusted valves following IT manual. All were loose but one in particular. Tractor ran fine, noise gone, but after about 30-40 hours, one lifter is clacking again. Exhaust on #5. Took one and a half or more turns on the adjuster to bring it back to spec. Top of the adjuster is now near level with the top of the locking nut. All others standing up. I'm still looking but so far see no damage to the rocker, top end of the push rod, adjuster or tappet. Would appreciate some thought from International guys about what I may be facing here.

Wiped cam?

(quoted from post at 17:41:00 05/20/20) Wiped cam?

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Bent push rod? Lifter end failed on push rod?

Cam lobe headed south?

If the pushrod and valve tip look good.
Also could be the rocker is wearing into the shaft.

If the cam is wiped, the lift will be very different than the others Intake or exhaust might make a difference, use the kind it is. Pushrods can get shorter if the lube to it fails. Check that as well. is it running well? does the valve stand the same height as the others with a straight edge across them? Good luck, Jim

You have to measure the lift of the camshaft. Those tractors have a reputation of wearing out the camshaft lobes. Many, many changes were made to the lubrication of the cam lobes. The problems really started but not limited to the time when they went to the pressure balanced pistons. This caused more blow by and they put a larger breather on top of the valve cover instead of the smal one out the side of the block.

This changed the lube of the lobes a little as the blow by out the breather on the side of the block also provided a little lube to the camshaft. Realize, that camshaft is enclosed and not exposed to the crankshaft on those engines which normally throw a lot of oil onto a camshaft.

Hello Pete, I found a discussion about the 400 series engine and camshaft issues on Red Power about 10 years ago. One of the voices back then was maybe you, made a lot of the same points. I have not been able to measure the camshaft lift as yet although my engine does not have a breather on the valve cover.
Although there are a few other things to check, consensus here seems to be cam lobe. R & R of the camshaft would be an undertaking in my shop and on a higher hour engine I'm wondering if rebuild or replacement would be better than just addressing the cam. Was there a reference to a later version of the block which might have the cam lobes open to oil splash from the crank? John LaBoyteaux

Checking the lobe lift would be my first thing I would do. If good, then you can search other problems. I think it is no use wasting a lot of time checking all the other possibilities when it sure looks like lobe problems.

Never heard of 400 series engines that opened up to get any lube from crank case. All comes down from the top with different variations of nozzles that feed a stream of oil down the push rod.

Like I said before, cam failures did occur with side breathers but only after a whole lot of hours where as the top breather, before they added better oiling had premature failure rates.

Just to add a little more information. The original version used a small v shaped slot in the rocker arm support bracket to provide oil leakage down to camshaft. Probably never even notice it if you were not looking for it. Then they added nozzles, different sizes to different rocker arm supports. Then put nozzles on all supports.

So, sometimes that went smooth and worked fine. But, sometimes the oil supply was not sufficient to those nozzles. They are fed from a groove in the block under the rear camshaft bushing. That groove and the passage through head can get slugged up or just too small in the first place.

With all the cavitation of sleeves on original versions of those engines, before we got into adding a filter with coolant additive or just adding to the coolant, a lot of engines were tore down. At that time it was easy and normal to pull the lifters to check for wear . A whole lot of lifters were replaced at those times which again extended the life of the camshaft. Severe pitting was what usually showed up and not actual wear patterns.

You just never know what you will run into but some things to think about.