Valve removal?

[Paulinkansas]

I recently bought a used tractor and it smokes excessively. Droplets of oil actually come out of the exhaust and it runs down the pipe and burns on the muffles. It's a gas AC D17 III made in 1963. It starts smoking about 2 or 3 seconds after the engine starts running. I strongly suspect the valve seals are worn and letting oil into the cylinders.

So I removed the head. There was about 1/8 to 1/16 of an inch of oil in the cup of each piston.

I borrowed a valve removal tool, the kind that has two clamps that hold onto the bottom part of the spring and then you screw the top down to compress it.

The problem I'm encountering is the flat portion on top of the spring isn't moving down when when I compress it. The bottom of the spring just moves up. What am I doing wrong?

 

[Mark W.]

You need to have the top part of the tool on the top of the valve and the lower portion under the spring. Once you compress the spring there should be a couple collars, or keepers, around the base of the valve. Remove these and then slowly release the pressure on the tool. Remove the tool completely and the valve should pull straight up.

 

[Howard H.]

Mark answered your actual question, but I'd be very surprised if valve stem seals are your whole problem...

If it's spitting that much oil, I'd guess your cylinder bores/rings are worn out, too...

Howard

 

[Anonymous-0]

Try the other type of valve compressor that is a big c shaped one that will hold the head of the valve, then it will compress the spring so you can get the keepers out.You may have to smack the retainer with a socket and hammer the socket the size of the retainer to jar the the keepers loose.

 

[Walt Davies]

Sounds like you bought a valve spring remover for a flat head engine you need to get the one for over head engines there are two types a C clamp type and one that has a bolt that screws into a bolt hole in the head and you press down to remove keepers. Also you can take a large socket and a brass or soft hammer and tap down on the spring and the keepers will just fall out don't loose any this way. But you will need the tool to re-install them.
Walt

This is what you want.

<a href="http://s77.photobucket.com/albums/j50/WaltDavies/?action=view&current=compressor8valve.jpg" target="_blank">

</a>

 

[Paulinkansas]

You and Walt hit the nail on the head. It's an OHV engine. I'll return my current spring compressor and get one like you describe. Many thanks.

 

[Anonymous-0]

You can use the compressor tool your describing,but first you have to hit the top of the retainer with a deep socket to break the retainer loose.Its just easier with the compressor shown.

 

[JMS MN]

I&T has a manual for the D series- it"s not AC11- that is for the older tractors. Maybe AC17? Anyway- it has spoecs in that manual for wear on the valve guides. I think too that if the problem is immediate upon startup, it is more than valves- too much blowby with the rings. Takes time for the oil to get up to the rockers and valves. I"ve notice upwards of a minute when adjusting valves with the rocker cover off.

 

[NEsota]

My experience with bad valve seals in auto engines leads me to believe that the oil smoke is most prevalent on start-up, after the engine has set and allowed the oil to drain down from the head. Little oil smoke is evident after start-up because then it burns only at the rate the oil seeps in. The head does not need to be removed to put in new valve seals. You position the engine rotation so that the piston is up and the valves closed. Then apply compressed air through the spark plug hole to hold the valves up while changing the seals.

 

[El Toro]

The engine probably needs to be rebuilt. Hal

 

[trucker40]

Its stuck on the keepers Tap it with a rubber hammer and it should come off of the keepers.From what you describe you might need valve guides and some valves.

 

[JT]

Well, I am gonna jump in here with my two cents worth. Normally when you you have bad valve guides on an OHV engine, it will smoke bad at start up, and then after a couple minutes it will clear up. At least in my experience, that is what I have found.
Jim

 

[JDemaris]

Kind of too late now, but it's pretty easy to put in new valve seals without taking the head off. Just hook and air-line to a spark-plug hole to keep the valves from falling in, and take the retainers off - one cylinder at at time.

In regard to valves making smoke at start up - yes but that is just one of the typical issues. Valve seals leaking will also cause smoke anytime the engine is running faster than the carb-shutter is open for - like when you hold yourself back coming down a steep hill with the trans in a low gear. Engine revs but carb-shutter is almost closed and the engine sucks oil through the valve-guides.
Also, if an engine is heavily sludged up under the valve-cover, the oil-drain-holes can get plugged, it fills up too high with oil, it leaks through the valve guides, and it smokes all the time. This was very common back when non-detergent oil was common - and just about never seen with modern oils.
Old diesels that used air-chokes for engine shut-offs were known for having bad valve-seal leak problems. Some older Mercedes cars would suck oil from the valve-guides and keep on chugging away when the air-choke was pulled.

Back to your tractor - since you DID pull the head - seems now you can look at the cylinderwalls and piston tops pretty close and see if they are scored, rings are loose, etc.

 

[Tom43]

Paul,
Since you have the head off, be sure and do a valve job,rings,and bearings at a minimum. You have already done half the work and you won't regret it.

 

[jose bagge]

The new seals will help, but you've got an oil return issue somewhere as well...there just flat out shouldn't be that much oil in the top end. I had a similar problem with the 4.3 GM in my daughter's el camino- smoked like a freight train, so I figured guide seals. Well, it sure was- the old seals cracked to peices and clogged the drain holes in the head, and there was about a quart of oil in each valve cover! new seals, clean drains, good to go!

 

[Anonymous-0]

Junk it, ok not worth crap. Old iron price. ok

 

[Paulinkansas]

Thanks alot. It's the best advice I've heard so far. Good luck to you too.

Paulinkansas

 

[onefarmer]

The keepers are stuck in the retainer.

First thing I do when getting ready to remove the springs is take a light hammer, and tap the retainer toward the edge just enought to break them loose. DON'T hit the end of the valve, just the retainer. Then use your spring compressor and they should come loose with little effort.