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1924 Light Six Valve Rocker Arm Removal?


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I own a 1924 Light Six and need help or advice in removing the valve rocker arm assembly without pulling the head or valves. I have limited mechanical experience but am learning quickly. I purchased a repair manual and it states that the valve rocker arms can be removed and replace quickly, estimating a half hour. It states that I need Studebaker tool SD-62, to remove the nuts holding the assembly in place, which I would guess is extremely difficult to locate. I can’t get a socket on the nut in order to turn it, due the clearance to the valve springs, and turning a wrench on it would be difficult.

Does anyone have experience with this or own the special Studebaker tool?

Here’s a bit of history on the problem: The car developed a miss. I found I have no compression in cylinder No 6 and upon removing the valve cover, I found that one of the valve rocker arm rollers had fallen out. I removed the screen from the bottom of the oil pan and found the roller, still in very good shape, but have not yet located the pin that held the roller in place. If I can remove the rocker arm assembly as described in the repair manual, I should be able to have a good machine shop put the roller back in place or make a new one.

I’ve been told I’ll have to pull the head so I can remove the valves and then the valve rocker roller, but this seems pretty extreme, given the ease of repair described in the manual.

I appreciate any advice on this.

<O:p</O:pThank you,

Dave

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Hi Dave

You need a crowsfoot wrench which should be available at most tool sales places. These are short wrenches which have a 3/8 drive square in them. Get the one with the open end the same as a normal wrench so it can be slid onto the nut from the side. Using a 6 inch 3/8 extension and a ratchet(and a little luck :)), you should be able to break the nuts loose. Position the engine to reduce valve pressure as much as possible. It is slow, but if the stars are properly aligned, you may be able to remove them with your fingers once the tension is released. Good luck(BTDT).

Terry

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Hi Terry,

Thanks for your quick reply. :) I'll stop at a hardware store and purchase one of these and give it a shot. Someone also suggested that I take a socket and cut it down to the minimum depth needed. This might give me the clearance I'll need, but will take quite a bit more work (I'd have to use a hack saw or the like).

I'm not a mechanic, but can guess that held the pin holding the roller in place is a press fit, and perhaps a split pin (?). I would hope that a good machine shop should be able to help with this.

Do you know if this a common problem? It might be interesting to know why the pin fell out, other than the fact that the car is 87 years old. (The engine's got great compression on the other cylinders and ran strong until this happened).

Also, the manual said to remove the cotter pins and nuts. None of the nuts have cotter pins and I would guess that the nuts are torqued down. If that's the case, do you know what the torque specs might be when I put this back together?

Again, thanks for your reply!

Dave

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I took a look at my 27 Dictator engine which is out of the car right now. It appears that the pin is a press fit which is staked in place. Definitely something a machine shop should be able to do. I've been involved with these engines for over forty years and haven't heard of any problems with the pins.

Torque specs for engines of this age don't exist. If you want to go that route, any high school auto mech text book should have a chart listing maximum torque levels for different grades and sizes. The alternative is to run them up until they are tight and give them another half turn :). Kiddin'. ;) The lack of torque specs is one reason for the cotter pins.

Terry

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Hi Terry,

Thank you for the information. I purchased some crowsfoot wrenches and was able to get in there and loosen the nuts, :D but it's a tight fit and I'm going to have to work at this a while (more tomorrow night)! It's tough with the engine in the car, as I'm working around the steering collumn, moving the nut a fraction of a turn at a time, while hoping I don't lose the wrench off my the extension and down in the pan. I really appreciate your interest and advice! Hopefully, I'll have this off the car and to the repair shop this weekend.

Thanks again,

Dave :)

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You mentioned that you found the roller, but not the roller pin. I suggest you take a small magnetic retrieval tool and fish around the oil pan for it. If it found its way to the bottom of the oil pan, it'll probably stay there and cause no problems, but if it ended up in the connecting rod oil drip tray, it may be caught by a connecting rod dipping finger and do some damage.

I bought a small telecoping magnet tool at the auto parts store and was able to work through the valve side cover to drag it through the oil retaining slots in the tray to retreive a valve keeper I dropped. (FYI - the oil tray I mentioned is situated in the oil pan about 3 inches above the bottom and is retained by four nuts to the oil pan itself.)

Good Luck,

Scott

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Hi Scott,

Thanks for your input. When I pulled the screen off the oil pan, I had taken a magnet and run at every angle I could to try to find that pin, but came up empty handed. I was going to pull the pan off, but was told it probably wouldn't hurt anything if it's sitting in there, but your words are food for thought. I'd hate for it to get kicked up and do some real damage down the road. I better see if I can locate it from the top side, or pull the pan so I can be sure what happened to it.

Terry, Scott, Anyone with experience -

Back to removing the rocker arms - it took some work, but I finally got the nuts and lock washers off. According to the manual, I should have been able to just remove the rockers at that point, but surprise, surprise! It won't budge. Try as I may, it won't even wiggle. I thought there should be some movement, even a little, but none. Now remember, I have no experience at this - but upon closer look, it appears that the threaded (studs/bolts?) that I removed the nuts and washers from have a sleave over them, between them and the rocker arm (brackets?), holding it to the block. Could it be it came that way from the factory? It's such a tight fit that I'd swear they really look like they're helicoils and those (studs, bolts) are threaded into them. But that makes no sense. The only way they could have been screwed into the block would be if they were double nutted and tightend down - Ok, now I'm rambling. But, as I stated earlier, there were no cotter pins, and no holes to put them in. Are they original? They look the same down the side of the engine for all of the rockers, so I'd guess this is Ok. The only reason I bring it up is in case someone's changed them over the years.

I can't figure out how to get the rockers off the car at this point. Does any of this make sense? There's no tension on any of the valves, as I've backed the adjusting screws off. The manual gives 1/2 hour to remove and replace the rockers. It can't be that hard.

Thanks again for your advice.

Dave

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Apparently the studs have been replaced at some time. Mine were replaced with bolts. Was there a gap between the nut and the rocker arm supports? Does that sleeve look crushed? Could be a problem. :(

Terry

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Let me start by saying I sold my 1924 Light Six a number of years ago, so my memory is getting weak.

One thought; if you have no compression in a cylinder that means there is a valve that is open, likely stuck open. That may be what's caused the roller to end up in the pan, due to the lifter not being able to open the valve and something had to give and that was the roller pin. You may want to check the cam lobe for possible damage.

See if you can move the valve that has the broken lifter roller. You should be able to get a large screwdrive to use leverage to get past the valve spring compression. Try a couple nearby valves first to see if how much pressure it takes to move the valves.

I had a 1923 Light Six parts car that had been sitting for a long time and it had two stuck valves, the very last ones in the block (#1 & #6 cylinders). I freed the valves by tapping and working them up and down with WD-40 being liberally applied. I am afraid however you will need to remove the head to access the top of the valve to tap it down.

One last thing, if you end up removing a valve I recall that the valve keepers are PIA to free up until you get the hang of it. You have to compress the spring and then kind of jiggle and push up the bottom retainer in order for the keepers to release. It's hard to describe, perhaps someone else can provide a better explanation

Anyway good luck, don't lose faith.

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Dave,

My 1923 Light Six has bolts instead of studs. Apparently they were changed over at some point as all the fasteners on the car have bolts machined on a lathe with no markings on the heads except for my rocker arm bolts which indicated a grade 8 (6 star marking). I must say that the bolts are an extremely tight fit in the rocker arm supports and have to be unscrewed or tapped out with a hammer. You may be experiencing the same issue on your studs. You may have to remove the valves to get at them to pry out.

My engine has the aluminum head which is a lot harder to get off vs your cast iron head. It really isn't terribly difficult to get the head off and it will give you the opportunity to clean up any carbon, check the overall condition of your cylinders and you could clean up your valves or even do a valve job. This may be more than you originally bargained for but again it really isn't that difficult.

To pull the head you'll have to drain the coolant, removed the upper radiator hose, remove all the head bolts and pry the head up with a few screwdrivers. New head gaskets are available on eBay or from Olsons's Gaskets (http://www.olsonsgaskets.com/).

If you do go this route, I found that tapping each spring retainer with a hammer a couple of times, before removing the springs, breaks them loose from the keepers. The next step would be to get a valve spring compressor. After compressing each valve spring the parts will be easily removed. Just make sure you label everything so it goes back in the same location from which it came.

FYI - pulling the oil pan would give you the opportunity to clean any crud out of it - mine had a lot. Olson's has new pan gaskets too (it takes 4).

Scott

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Hi Terry,

No, there was no gap at all between the nuts and the rocker arm supports, and the sleaves don't appear to be damaged. Also, the studs (or bolts) are such a tight fit, which is why it looks like they're actually threaded into the sleaves, (or helicoils). I'm also starting to question whether or not the rockers can really be removed without removing the valves, as the supports don't appear to have enough room to clear the springs, much the same as what I was facing to get a tool in there to remove the nuts. I need to slow down and not rush this. At this point, I'm going to have a friend from the Horseless Carriage Club come by and have a look. I need to slow down and be patient. In the mean time, I think I should order a head gasket and get ready.

Thanks again,

Dave

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Hi Dave

Nothing like having a curve ball tossed at you, is there? :( Having said that, patience is a virtue so I'm told. :) Time to slow down, take a deep breath, have a beer(or two or three), and throw a stick of dynamite at the #&%@# thing! Seriously, it sounds like someone went to a lot of trouble replacing the studs. I'm having trouble trying to visualize what you've got.

Give the shaft mounts a rap at the bottom with a brass or aluminum drift. If they were double nutted to put them in I can't see them being too tight, maybe they might come out the same way. Don't know what else to suggest, otherwise. Maybe the line of least resistance is removing the cylinder head. It's easy to do.

Terry

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Hi Terry,

Well, it comes to this - I was finally able to break the rocker arm supports free from the block. The lock washers were put on so tight that they left an impression in the metal, giving the impression (from a distance) that there was a helicoil. Not so. Again, I was able to break them free, but I'm back to the fact that the studs are just a bit too long. There's just no room between the rockers and the valve springs. The head's coming off...

I'm ording a head gasket, getting a valve compressor, and will finally get on with this! I'm sure I'll have more questions, but for now, I'm set.

I appreciate all the advice and will update this post when the job's done in a few weeks.

Any chance you know what the torque settings are for the head bolts on the Light Six?

Thanks!

Dave

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Dave,

After you remove the head from your engine, I would remove each valve/spring/retainer assembly and keep them in order. I took a piece of wood, drilled holes in it and marked it with the cylinder number and either In (intake) or Ex (exhaust). I placed each valve (with spring & retainer) in the holes to keep them in order. Besides replacing your roller, you'll want to scrape any carbon off the pistons, valves and combustion chamber. I placed my Shop Vac pickup right in the cylinder to suck up all particles to avoid getting the stuff between the piston and cylinder walls. Inspect your valves and seats to look for any excessive wear or burning or leakage. They should look fairly uniform all the way around. If you find a problem you may want to get them lightly ground (valves and seats).

To ensure a leak free seal on your cylinder head, you will want to clean the surfaces of the block and head - scrape, brush, solvent....get it really clean. Hopefully you’ll get a new gasket which will be copper-asbestos-copper. Make sure you get the right gasket, as there are a few different versions for the Studebaker sixes – compare it to the old one. I would install the gasket dry (no sealants). The copper will form into the irregularities on the castings and the asbestos will compress.

Unfortunately, there are no published torque specs for the early vintage cars. That said, I would use no more than 70 ft lbs, which is the low end of the spec for a grade 5 bolt. If you have some studs that look a bit rotted, you may want to go a bit less on those. You will want to use a drop or two of oil on each thread and torque in a sequence starting in the center of the head, working your way to the ends, back and forth from the center. Gradually ramp up the torque following this sequence. This means you will torque each nut down at least 5 times starting with a light snug, then 15 ft lbs. After each nut is at 15ft lbs, move to 30ft lbs and follow your sequence, then 45ft lbs and so on. After you run the engine and warm it up, you will want to re-torque it one more time.

Good luck,

Scott

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Hi Dave

Darn! :( After some thought I might have another course of action. The illustration in my service manual indicates that the rocker arm support stud nuts are flush with the end of the studs when they're tight. It is just an illustrator's rendering, but hopefully it's accurate. It doesn't sound like that is the case on your engine Would this work? Put the nuts back on and just snug them up. Take a die grinder or Dremel tool with a small cut off disc in it and cut the projecting part of the stud off flush with the nuts. Remove the nuts and hopefully the rocker shaft.

Failing that, taking the cylinder head off is about as easy as it gets. Is yours held on with bolts, or studs and nuts? Beyond that, there are some complications. Finding a valve spring compressor for a side valve engine might be a challenge. Presumably the illustrations in your manual are the same as mine. Note that the compressor has an arm that fits into the spring above the retainer plate so that the spring is compressed against itself when the compressor is closed. The ones available now likely won't have that feature. I have had the valves out of my car twice, but both times the engine was out of it. (I've owned it for 45 years.) I used an overhead valve spring compressor. To do that, the manifold had to come off and you have the added complication of the steering column. :mad: Even with the right compressor, you'll be standing on your head to get it in. The spring keepers are designed to stay in the retainer plate when they are removed from the slot in the valve, but it goes without saying that something should be put under the valves to prevent anything falling into the engine.

As I mentioned earlier on this post, torque specs for engines of this age don't exist. For a 1/2 inch bolt with 13 or 20 threads/inch on a low compression engine using a composition type gasket - what virtually all old cars used - probably 40 pounds would do. The last time I had the head off mine I did it by feel. :)

I hope my idea works. Keep me posted.

Terry

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Dave,

The Light Six has angled valves so today's overhead valve spring compressor works fine. The one I used had a deep enough throat to clear the manifold. You might want to stick with Terry's recommendation on torque. If you do get any leakage, just increase the torque level.

Scott

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Hi Guys,

Thanks again for the advice. I fear if I try to put the rockers back on the car, snug down the nuts and cut the studs off, I'll just create another mess. Yes, the studs do protrude out further than the nuts did, so, these do differ from the illustration, but getting a dremel tool back in there next to the valve springs would worry me to death.

I'll try to locate an overhead valve spring compressor and dig in after I get the head gasket. Although this is supposedly a somewhat easy job, I'll be taking my time. To take the manifold off I need to first remove the vacuum for the fuel system, etc. This is all bigger than I was hoping for, which is why I wanted to avoid pulling the head, but I think this is the right thing to do.

I'll update this in a few weeks or so to let you know how it turned out, but will continue to monitor this thread to see if other advice is given.

Again, thanks,

Dave

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  • 2 weeks later...

Hi All,

I struggled with the decision to removed the head so that I could remove the the entire rocker assembly. Realizing the enormous task (well, for me), I decided to do this in another manner. I was able to get one of the two rocker brackets off the stud. Getting the assembly at an angle, I was then was able to remove the cotter pin holding it together, then slid the rocker arms off the shaft one at a time until I got the bad one. Yeah! :D Putting the whole thing back on the stud could prove a problem later on, but for now, I’m happy. I also found the pin in the oil pan, and it looks fine. The roller, upon closer examination has a slight flat spot, nothing bad, but I’d prefer to replace it if possible. The rocker arm, however, had a big chunk taken out of it when the cam came around, creating a notch in the metal below where the roller sits. This wouldn't affect the movement of a new roller, and the rocker is still very usable, but all in all, I’d like to find a complete rocker, roller, and pin from another Light Six if possible. The cam looks good, but has a very slight nick on the edge of the lobe on one side and there’s a bur at that location that I’ll file down, very carefully.

It was immediately apparent upon examination of the rocker arm that this was a factory defect that took 86 years to present itself. Each rocker has 4 spots on each side where it’s peened to hold the pin in place. The bad one only had 2, as it was off center, and the other 2 would have been where the pin is located. I took everything to a good machinist but he suggested that I look for a used rocker with a roller still in good condition, at least until I need to replace all of the rollers.

Over time, the pin had worn the hole in the rocker and it’s not a tight fit anymore. I know we can use a larger pin, but I’d just as soon get another rocker if I can find one. Folks who have helped me in the past don’t have one, so I’m making calls and hoping for the best. I’ll open another thread in this forum if I don’t get a response to this request.

If anyone knows where I can buy a rocker assembly for a 1924 Light Six, I’d be grateful.

Thanks!<O:p</O:p

Dave<O:p</O:p

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  • 4 weeks later...

Great News! She's running again! :D Thanks to everyone who provided guidance as I worked through this problem. As said, I don't have a lot of mechanical experience, but learned a lot from working through this - much more than if I had taken it to a garage and paid someone else to do the work. It cost a lot of time, but am proud to say that it was very easy on the wallet. ;) I also came away with some knowledge of the internal workings of the engine.

Per my prior posting, I didn't have to pull the head, but just disassembled the rocker arm assembly and slid the parts off until I got to the culprit. A good machinist filed the burs on the rocker arm, put the roller and the pin back in place, peened the pin and blessed it, with the promise it'll last as long as the rest of the engine has life. He was very pleased with the condition of the parts (maybe I overstated their condition) and when he was done, I couldn't tell the bad one from good one (except for the peening). Putting the rocker arm assembly back on the engine was a bit of a challenge, but taking a few thousandths off the edges of the rocker arm bracket allowed enough clearance to the valve springs and it slipped right into place.

I put everything back together with the help of some friends, and she started on the first try. Smooth as silk... We had also readjusted all the lifters, so she's much quieter. Runs and sounds wonderful...

Thanks Everyone!

Dave

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