The Stovebolt Site Forums The Shop Area Engine Shop '56 235 has an issue, need some help (again!)

I almost hate to post this, since I've had one issue after another in the last year, but here goes- the '56 235 in my '51 has a total of around 30-35k on it since it was rebuilt by a professional rebuild shop before I bought it from the previous owner. The PO had the truck for decades, and was himself the owner of a shop before he retired and continued(s) his first love, which is restoring model A's &T's. Anyway, I've had this truck for about 8 years now, and it's been my daily driver until last spring when it stripped it's timing gears. (Been driving my '04 Silverado 3500 4x4 diesel in the interim). You all have been a big (giant, actually) help in that. I had a local shop do the change out on those gears, formerly the soft ones and now metal, and when I first got it back, it seemed to start willingly, with a little choke and throttle play, but it seems to "drag" when trying to start. Once started, it does fine, except for this weird sound coming from the engine, and specifically from around the center of the block, best I can tell.

So, last week I called up the shop that my wife and I have used for the last 15 years for oil changes and tune-ups, especially before I retired and was working long hours an hour away. Anyway, Steve, one of the two owner operators of Accu-Tune in Farmington, Missouri (shameless advertisement for the boys, there), who loves working on old cars and trucks, ("I NEVER get to do the fun stuff anymore! All these new cars are boring!") to see if he would take a listen and see what he thought.

I had already put in new plugs, rotor cap, points, condenser, coil (in case the old one was weak and causing the starting issues, and even a new resistor just in case. After that, I adjusted the valves, which I'd not done since I acquired it. (Two intakes were tight, one exhaust was a little loose). I'd just replaced the plug wires not long before the timing gears went. When I got to the shop, he was pulling a customer's car around, so I asked him to jump in and take a ride around the block to listen to what I was hearing before he looked at it. To me, it sounds like a can rolling around in a cardboard box (closest description I can figure), with a little 'roughness' like metal rubbing, but not screeching. I told Steve that when the shop that changed out the timing gears checked the cam shaft, he said it looked brand new and didn't need the new one I had sent along 'just in case'. (I'd asked Steve and Matt if they would do that job, but they said they weren't set up for the job, so I took it to my diesel mechanic and he did it) I left it with Steve and called him at the end of the day. He said he checked the timing (it had gotten to be an ordeal just to get it started, and I wanted him to adjust it if necessary), and said the dwell and all other possible checks were fine, aside from a slight adjustment of the carb, which I forgot to reset after messing with it. He was really surprised, he said, when he looked down one of the pistons after pulling a plug and found it so shiny, clean and looking nearly new. He couldn't believe how good it looked. So, after all the good news of what wasn't wrong with it, he said he couldn't tell me what it was, but said he was concerned that there may be something going on with the crank shaft.

So, what might be the deal with the crankshaft, or does anyone have any clue about other issues that may cause this noise? I've been on here many times leading up to this post, and have gotten a lot of help and information (thanks to all, especially Hotrod Lincoln, who seems to come to everybody's rescue with just the right answers). And when I first posted about the day I fired the truck up at my daughter's and it revved up when I started it (way up), and I immediately shut if off due the high rpm, only to have it never start again. Cranked, yes. Start, no. At that time, I was told to check the push rods and cam shaft in case any damage was done on that high rev start up, even though it was only running for 3-4 seconds before I killed it. As I said, the shop that replaced the gears said the cam looked brand new. I'm pretty sure I told them to check the rods, and the side panel that exposes the push rods was opened, because they installed the new gasket I left for the job. (I furnished all gaskets, gears and camshaft and oil, and told them to call me if it needed rods or anything else. It didn't). So now, the one thing that I didn't ask them to check, the crank, or something down I that area, is sounding not good. I'm more of an "exterior" shade tree mechanic, so the guts and deep stuff are foreign to me. My fear is that even if I was able to do a job in there, the cost in time, money and cuss words if I messed up or missed one thing, it would be expensive to re-do, and I am not a fan of re-work in any area. So, I'm now in a pickle on what to look for or do next. I still have a buddy who has a complete 235 he's willing to let me have to install in the truck while I have mine rebuilt, but he's busy all the time, and it would be done when he could get to it. He's a retired Ironworker, too, but he's got a house rehab, a property to maintain and a son changing out an engine going on now.

My big question- What the heck is making that noise, and what might it take to fix it? I wish there was a way to record it and let people hear it, but I don't know how to do that. Sorry for the long thread here, but I figured I'd better get everything in so it would be clear. Thanks for any help, fellas. I'm stumped and so is my mechanic buddy.
Lee

Any idea of the actual procedure that was used to replace the gears? Was the cam removed for the aluminum cam gear? Do you know if they pulled the pan to use a pinch bar on the crank while they hammered the crank gear on (assuming they installed a new gear), or did they drill the crank snout for a bolt and use a regular gear installer? I ask this because its not all that difficult to mess up a marginal crank thrust main bearing by hammering on a gear or the balancer, unless you are stabilizing the crank forward so that it does not get pounded back into the thrust bearing.

OK- - - - -let's tackle one issue at a time, sort of like picking out one bird on a covey rise of quail instead of trying to shoot the whole bunch at once! The "drag" when starting- - - - -see if the engine will spin freely if you step on the starter pedal without turning the ignition on. If it only drags while actually trying to start, you're dealing with an ignition timing issue. If the slow cranking is there all the time, ignition on or off, then we need to troubleshoot the starter circuit- - - - -particularly the ground side of the equation. Are you running an original 6 volt electrical system, or has the truck been converted to 12V? There's nothing wrong with 6 volts, but clean, tight connections, BIG cables everywhere, and routine maintenance of those connections is a must.

Once you deal with the slow cranking situation, then it will be time to start diagnosing noises. I've made good use of a broomstick or a hardwood dowel rod as a field-expedient stethoscope for about the past 60 years. Once you get a close location for the noise, start narrowing down the possibilities in those areas.

Where in "southeast Missouri" are you? I've got a business appointment in Jonesboro Arkansas coming up around the middle of next week.
Jerry

D- Yes, they pulled the cam shaft and said it was in near new condition, so they didn't put in the new one I took them in case it needed it. Per dropping the pan, I'm sure they did or they wouldn't have been able to pull the timing cover due to the two lower bolts being inside heading out. Per whether they pulled the crank, or stabilized it, I have no idea, but I'll find out next week. Good lord, I hope they did, because I told Andy (the shop owner) that the main reason I was hesitant to do the job myself was that I had heard from a couple guys on this forum about the possibility of driving the cam shaft in too far and screwing up the rear seal. With 30 years as an Ironworker, and the 10 before that as a shop welder, I've spent half my working life pounding the crap out of steel with 4 and 6# beaters. The idea of smacking that shaft a bit too hard, when hard is how I smack steel, I figured I would certainly mess it up, and it wouldn't be just the timing gears that would need fixed. So I hope the hell they didn't do that. And how would I be able to tell if it was hit too hard?? (One of Andy's men has experience with these motors, so he had an employee change them out, but I did send the shop manual with the truck and parts, so he had a reference book). So I hope the hell they didn't do that. And how would I be able to tell if it was hit too hard if it was? But I will be talking to Andy and his man next week to see exactly what and how they did it. Thanks for the help, Mike.

Jerry-It was converted to 12 volt before I bought it. Although I rebuilt the generator (brushes were half gone, literally), the starter has never been an issue yet. But I was wondering about that, too. It's 8:30 at night and about 20* out on the curb, so I'll have to get out there tomorrow and try the starter. I'm sorry to say that just the other day I was showing somebody how the starter will crank without the ignition on (to show how I make a fool of myself sometimes when I try to start the truck but forget to turn the key on, then after a minute realize the key is off. duh. But I can't remember now how it sounded. But I'll check. So, somebody educate me here. The ignition timing- is that not the same as the 'timing' of the timing gears? Steve said the timing was good. I may be ignorant of what you're talking about. If I've never had a problem with something, it's new to me. What's the difference?
I actually just picked up a mechanics stethoscope a couple of weeks ago. Guess it's time to put it to use. The last time I went out and tried to start it, it wouldn't start. Since school had just gotten out not long before I went out to do it, there were teachers heading out to the parking lot. And I absolutely hate it when I'm working on something when I've got an audience and it isn't going right. (I'm still mad at my wife for talking me into buying this place in town. I belong where I'm not within sight of any human being. Living in any city limits is a form of torture for me.) So the bomb has sat out there all week untouched.

We live in Park Hills, Missouri, formerly Flat River until they decided to make one big poor former mining town out of 4 little poor mining towns. St. Joe Lead mining use to have the biggest lead mine in the world here, but they closed the mine in the 70's and this once prosperous area dried up when they left. At least we have an 8,500 acre state park here now. (St. Joe/Doe Run Lead gave the property to the state of Missouri to get out from under the taxes when they pulled up stakes) St. Joe State Park is the dirt biking, 4 wheeling mecca of southeast Missouri and east Illinois. Speaking of Jonesboro, I worked on a glass factory smelter down there about 15 or 20 years ago. It's about 200 miles from here. I think it was a 3 hour drive when we went down for that job. (I got highway pay, so I remember that).

Ok- - - -that pretty much eliminates the idea of a visit while I'm "in the neighborhood". Since Monday of this week, I've driven over 1200 miles in 5 states- - - -and I'm supposed to be "retired". What's that? Next week, I've only got 600-something miles scheduled- - - -so far!

Ignition timing is different from camshaft timing. It determines when the spark plugs fire in relation to the position of the pistons. Too early, and the spark tries to run the engine backwards while starting and bogs the starter down- - - -no Bueno!
Jerry

Ahh. That's the timing I'm familiar with and what Steve would've checked, and he said it was good. I checked as well as I could before I took it down to him, but since it was still not right, I wanted to take it to someone that was more than hoping he'd done it right. So, then, what does camshaft timing involve? How do you know it's right? Could the guy have stuck it in there wrong or 'out of time'?

On a stovebolt cam timing is simply a matter of aligning a couple of dots center punched on the crankshaft and camshaft gears. It's not idiot-proof, but somebody would have to be pretty incompetent to mess it up. A 235 has some flat spots milled into the camshaft for clearance between the connecting rods and the cam, but there would be lots of other symptoms including probably not running at all, if the cam was far enough out of time for the rods to hit it. It's a huge job to check the cam timing, involving removing the balancer and the timing cover and checking the mesh of the timing gears. There's a way to check cam timing by watching the action of the rocker arms in relation to the timing marks on the flywheel, but that would require writing several paragraphs of detailed instructions. Let's hope you can discover a simpler problem before jumping into major surgery!
Jerry

Spent yesterday helping my brother in law with his plumbing, so I'm just getting back here. Good news is, I went out just now and tried cranking it without the key on and, yes, it sounds fine that way. To my surprise though, even though it seemed to 'lope' and drag a bit with the key on, it fired up on the second try, with the choke all the way out and the throttle at about an inch out. Also, it's pretty nippy out even at 36* with a stiff breeze, so now I'm thinking I may have flooded it the other day (when the teachers were filing out) when I poured some gas down the carb after it wouldn't start a time or two. I left the throttle out and decreased the choke a bit after getting out and moving the Silverado out of the way, then took it around the block to park it back in our level so-called driveway, mostly to get it out of the way and clear the curb.

So, if it drags just with the ignition on, then it's an ignition timing issue?? That's odd, because Steve said the timing was good, so that's got me scratching my head. But if there's a chance the cam wasn't placed correctly, and that would cause 'rubbing' noises, which I won't know until at least tomorrow when Andy's shop is open. Am I correct in that? Now, as bad as I hate to pull the oil pan that is not leaking with new gaskets (My experience with oil pans, specifically, is pretty sad. No matter how well I seal and torque them, I always get a leak), it seems I need to check if those marks on the crank and cam shaft are lined up. Would that be right? (After I ask the shop what they did per cam timing). But, as usual for me, it fired up on the second attempt. I'm now starting to question my memory on whether this sound was there already, since it's now been almost a year and a half since the gears stripped and I last heard it "normal". Since the old truck is so loud when I get it out on the road, I was in the habit of putting in ear buds to listen to music instead of the road noise. But I'm pretty sure this wasn't ever present before that. It's not even loud, sort of like the rubbing sounds of an old washing machine winding up into a spin cycle.

Also, as Mike mentioned, if it was hammered back in to hard/far into the thrust main bearing, what would be the symptoms? A rubbing, rolling sound? What I've described as a rock or can rolling around, (as if the rock/can is rubbing on the side of the box as it slides by, sort of), could that be a bearing rubbing or just the bearings rubbing against the cam or other bearings in itself? What is the fix if this has happened?

Don't start a teardown yet- - - -there are some simpler ways to check cam timing. Maybe a PM or a phone conversation with your engine builder might be in order to discuss specific procedures to see if the cam is installed correctly without a big disassembly. The job is a little convoluted, but anybody who can build an engine should be able to discuss it in pretty good detail. It involves finding true top dead center of a cylinder, and then watching the operation of the rocker arms from that point.

So far as starting goes, turning the distributor housing a little bit clockwise by using the "octane selector" slot in the bracket that holds the distributor to the block might be in order.
Jerry