I have a 1961 261 for a 46 chevy 1/2 ton. I removed the flywheel,clutch and bellhousing to install a 46 rear mount bellhousing. When installing the flywheel had it align but still pushed in 2 of the 3 pins. Now it won't turn. I removed the spark plugs. Could the pins keep it from rotating? How do I get the pins back out?
Those dowels are offset slightly so the flywheel will only fit in one position. The bolt holes are evenly spaced. It looks like you failed to align all the dowels before you tightened the bolts. If the dowels can be drilled and tapped for a thread, you might be able to install a stud into the ones that are pushed inward, and use a socket over the stud and a nut to retract them. You will probably need to have a machinist make some new dowels once that's done, since a dowel with a hole in it will allow oil to leak- - - -the holes go all the way through the crankshaft hub. Ditto for the bolt holes.
If the dowels are too hard to drill and tap, good luck! Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
May be a hairbrained idea. Slide hammer (dent puller), a screw and a welder. If you can tack weld the screw to the dowel pin then maybe you can pull them pins out with the slide hammer.
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
Those dowels are far too tight of a press fit to get a weld to hold. Last resort method- - - -remove the crankshaft and use an electron discharge mill (EDM) to burn the dowels out. Buying another crankshaft would be less expensive, since it's the same as a 235 crank. A solid carbide drill bit in a very accurate drill press would be another option, which would also require removing the crankshaft. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
The dowels may only be case hardened. If so, you might be able to grind through the case with a die grinder and drill and tap from there. It's not going to be easy. Getting a machinist involved will probably make the most sense.
Note: If you break off a drill or tap in the hole it'll make matters much worse.
If the engine is out of the truck, it could be set up on a large horizontal boring mill and the dowels could be milled out with carbide. This option will not be cheap.
Sometimes, the smallest problems can create the biggest headaches.
Good luck.
John
~ J Lucas 2006 GMC Envoy 4.2 I6 2023 Ram 2500/Cumins 6.7 I6 2010 Jeep Grand Cherokee (Wife’s) 2002 Silverado 2500 Gas 6.0 1941 Chevy 1/2-Ton 1942 Chevy 1.5-Ton SWB In the Gallery My Flicker Photos!
Yes John I also believe the smallest problems can cause the biggest headaches. I was careful about aligning the holes because it can only go on one way. I bet I rotated it up in there 3 or 4 times to make sure. I have an old wise mechanic (father) coming over later today to see if some of his old tricks can work. If not time to tear into a 261.
Those dowels are far too tight of a press fit to get a weld to hold. Last resort method- - - -remove the crankshaft and use an electron discharge mill (EDM) to burn the dowels out. Buying another crankshaft would be less expensive, since it's the same as a 235 crank. A solid carbide drill bit in a very accurate drill press would be another option, which would also require removing the crankshaft. Jerry
If it comes down to it probably get a new crankshaft. I doubled if not triple checked the alignment before I tightened them down. I could see all 3 pin heads. So with the downs reset in there the crankshaft will not turn correct?
The dowels probably got pushed into contact with the block, the rear main bearing cap, or both. Now the concern is whether or not the block or cap has been damaged. Is the engine out of the vehicle? It's extremely difficult to remove a crankshaft with the block in the frame. The suggestion about grinding through the surface hardening on the dowel is a good one if it's not hardened all the way through. That's what we do when installing scope mounts on a hardened rifle receiver like an 03 Springfield. It would also be possible to anneal the end of the pin with an acetylene torch flame, but that might damage the rear oil seal. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
It would be tedious, but grinding the pin with a die-grinder till it's just a shell would allow you to collapse it and possibly get it out. Also, the welding idea is worth a try, and probably wouldn't heat the crank enough to damage the oil seal. If you wind up removing the crank, you'd have to replace the seal anyway. Some pins I have seen are stepped (smaller diameter in the crank than the part that goes into the flywheel or other mating part.) that would prevent them from being pushed into the flywheel like happened here.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
Jerry yes the engine is out of the truck. The was to swap the bellhousing and I stall the transmission. As always something something so easy turns into not so easy.
I'd suggest dropping the oil pan and do a close inspection of the area around the rear main bearing cap. Hopefully, something is just jammed, without any permanent damage to the block or the main cap. Loosening or removing the main caps might free up the crankshaft to get at least part of a turn. If the crankshaft needs to be removed, a lot of the front end has to be dismantled, possibly removing the harmonic balancer, timing cover, and the crankshaft timing gear, if not doing a complete disassembly. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
It's hard enough holding up the flywheel trying to rock it in on the pins, just to have something to help hold it up, while you take one hand away to grab one of the flywheel bolts. With the bolts in place but not tightened, it's still a tight fit. Rocking the flywheel back and forth a little, it eventually works it's way up against or near the crank. You can see the end of the pins. Then you tighten/torque the bolts. I'm wondering if the 2 pins were actually "press fit" tight to begin with. I know it is grabbing at straws. I really sympathize with the pain of having to open up that engine.
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
Those dowels are far too tight of a press fit to get a weld to hold. Last resort method- - - -remove the crankshaft and use an electron discharge mill (EDM) to burn the dowels out. Buying another crankshaft would be less expensive, since it's the same as a 235 crank. A solid carbide drill bit in a very accurate drill press would be another option, which would also require removing the crankshaft. Jerry
If it comes down to it probably get a new crankshaft. I doubled if not triple checked the alignment before I tightened them down. I could see all 3 pin heads. So with the downs reset in there the crankshaft will not turn correct?
Hog Wild That is a dilemma dont think I ever saw it before,I guess it will be a good time to clean your pan and inspect your bearings. Can't quite think of the space you'll have to work in once the pan is off,and if you'll have to disturb that rear main seal. Guess you can take a thin blade on your grinder, wrap the engine up to keep grindings out,then make space to pry in. GOOD LUCK...GOOD LUCK You can fix it !!!
Hog Wild You know when I ran the crankshaft grinder I had to remove those pins so I could index the rod throws,don't think they are hard because the punch would kind of dent them up. May be able to grind the back off (with pan on) drive thru more,grind off,till they are gone then find and install 2 more.
If you have access to a junk crank the process is easy. Cut the crank flange off the junker and bolt it to your crank with the flywheel bolts (longer bolts?) then use a center drill that just fits through the flywheel holes in the cut off flange and drill starter holes EXACTLY in the center. Dowl pins a NOT hard. Drill dowls to thread or collapse.
Since you have the engine out of the frame, pulling the crank might be a reasonable idea. When you do that the timing cover has to come off, giving you the opportunity to inspect the timing gear, replace the seal and install a speedy sleeve on the crank pulley if necessary, not to mention the gasket and the several 1/4" copper washers that go under the screws and get lost of forgotten when it was apart last. And of course you get a look at all the bearings and can replace them as necessary. Then there is the rear main seal, which always leaks, often into the clutch, especially if you just replaced the disc; otherwise it will go on the ground or the undercarriage. All of the above is far easier with the engine out of the truck. I have done all of these tasks in-frame, including pulling the flywheel and bell housing, usually in bad weather.
1951 3800 1-ton "Earning its keep from the get-go" In the DITY Gallery 1962 261 (w/cam, Fenton headers, 2 carbs, MSD ign.), SM420 & Brown-Lipe 6231A 3spd aux. trans, stock axles & brakes. Owned since 1971.
Ok got it done. Took about 2 hours at most. Removed the oil pan and main cap. The first one we punched it out. Took a few waxks but finally got it. Used a copper scrapper and a screwdriver to help protect the crankcase. The second one rotated to see it. It was stuck pretty good took an air hammer to push it. Then both we angle ground the inside edges flat with a magnet to attract any loose particles with the engine covered with a towel. Waiting on an oil pan seal and dry fit the flywheel on it.
Good show! Did you determine what was keeping the crankshaft locked up? Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
That's what I was thinking. I even had a picture ready for reference just in case. Glad you solved the problem. Is now a good time to replace the rear main seal?
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
Hog Wild Great good chance to clean and just look it over,once I saw your picture remembered that you clamp onto the seal area to grind. So I probably padded that area with shim stock or to center may use feeler gauge thin one anyway glad you got out of that one . Earlier I rolled in a complete set of rods and mains -.002 into my 51 6400 to fix a bearing noise in it. Makes you feel pretty good when you get one fixed !!
Hog Wild You know you are just a few miles over into Indiana from me.live about 5 miles from the Wabash river. Will try to connect in a few days tied up now on a job.
