Dataholic Posted September 27, 2011 Report Share Posted September 27, 2011 Hey guys how would I break loose the crank bolt on my L20b with the head off? Quote Link to comment
Laecaon Posted September 27, 2011 Report Share Posted September 27, 2011 On my L16 I just put on my biggest ratchet, and matching socket. Then curb stomped the ratchet. Bolt came out. This was with the engine out of the car. Could you also chalk the wheels, put it in gear and loosen it? Quote Link to comment
Sealik Posted September 27, 2011 Report Share Posted September 27, 2011 Is the timing chained wedged....? Quote Link to comment
Elkie Posted September 27, 2011 Report Share Posted September 27, 2011 Screwdriver wedged between the teeth of the flywheel. Quote Link to comment
Laecaon Posted September 27, 2011 Report Share Posted September 27, 2011 Is the motor still in the car? Quote Link to comment
Sealik Posted September 27, 2011 Report Share Posted September 27, 2011 Is the motor still in the car? Ya...a little more info would help... :D Hmmmmm....need to remove crank bolt....tensioner popped out....? Quote Link to comment
bananahamuck Posted September 27, 2011 Report Share Posted September 27, 2011 Get piece of angle iron drill holes so it bolts to block over one piston get that piston on way up ..put 2x4( piece of wood ) between angle and piston,,bring piston up till 2x4 stops upward movement turn bolt..... .profit Quote Link to comment
datsunaholic Posted September 27, 2011 Report Share Posted September 27, 2011 Use air impact gun. Failing that: Engine in vehicle (Manual): Put in gear (1st or reverse), block wheels and set parking brake. Remove with 27mm socket on 18-inch or larger breaker bar. Engine in vehicle, Automatic: You're screwed. Remove engine, then... Engine out of vehicle, transmission attached: Remove transmission then... Engine out of vehicle, transmission off: Remove clutch. Either use clutch mounting bolts (not recommended since they're small) or use flywheel mounting bolts (after removing flywheel) and a piece of bar stock to use as a wedging lever. Conversely (and better) you can bolt the bar stock to the crank flange and the top of the block (trans mount holes) to immobilize it. Quote Link to comment
Sealik Posted September 27, 2011 Report Share Posted September 27, 2011 Get piece of angle iron drill holes so it bolts to block over one piston get that piston on way up ..put 2x4( piece of wood ) between angle and piston,,bring piston up till 2x4 stops upward movement turn bolt..... .profit Well if the crank bolt is still on....would assume the TC, chain, tensioner etc are all in place. Probably can't rotate it. Impact....or socket/bar with someone jamming the flywheel with screwdriver. In gear with emergency brake on...if the engine is still in vehicle Quote Link to comment
datsunaholic Posted September 27, 2011 Report Share Posted September 27, 2011 Jamming the flywheel ring gear with a screwdriver or crowbar is a good way to break teeth off the flywheel. It sometimes works, but if the crank bolt has been on there for decades it generally doesn't come off easy. Quote Link to comment
bananahamuck Posted September 27, 2011 Report Share Posted September 27, 2011 Sealick I see what your thinking but i was thinking cutting the 2x4 length wise to fit ..but you would still need to rotate to make sure the piston is coming up and not away from you.. I was guessing that he was taking the front cover off because ( assuming here ) he dropped chain..Why else would you take crank bolt out.. Quote Link to comment
izzo Posted September 27, 2011 Report Share Posted September 27, 2011 I take out & put back my crank bolt all the time. Car loves it :w00t: 1 Quote Link to comment
datzenmike Posted September 27, 2011 Report Share Posted September 27, 2011 Someone was changing the head gasket and didn't block the chain and the tensioner fell out. Now they are trying to get the crank pulley off to get the timing cover off to find it. Quote Link to comment
Sealik Posted September 28, 2011 Report Share Posted September 28, 2011 Jamming the flywheel ring gear with a screwdriver or crowbar is a good way to break teeth off the flywheel. It sometimes works, but if the crank bolt has been on there for decades it generally doesn't come off easy. Yeah....have to be careful. I did it once....years ago....:D I tried blocking the tires, in gear, e brake applied......still moved the truck when I tried to break the bolt loose. Had no impact....so I had to use the flywheel method. Never thought about kicking the engine over to break the bolt loose with the socket and bar stabilized to frame or ground.... :blink: Someone was changing the head gasket and didn't block the chain and the tensioner fell out. Now they are trying to get the crank pulley off to get the timing cover off to find it. That's what I figured also.... Quote Link to comment
Dataholic Posted September 28, 2011 Author Report Share Posted September 28, 2011 Yeah motor is still in the car, I was replacing the head gasket and tensioner popped out. Thanks for help I think I'll try blocking the tires while it's in 1st and break it loose that way. Quote Link to comment
datzenmike Posted September 28, 2011 Report Share Posted September 28, 2011 I hate when that happens. I took all precautions when blocking the chain but learned another. Put the transmission in neutral. When in gear, leaning against the body while wrenching can jostle the vehicle and bump the motor forward or back slightly. I was lucky and caught it before it was too late. Quote Link to comment
Dataholic Posted September 28, 2011 Author Report Share Posted September 28, 2011 Thanks for the advice man. Quote Link to comment
Boaty Posted September 28, 2011 Report Share Posted September 28, 2011 That tensioner, is the biggest PITA ever. I thought I'd be nifty and block the tensioner from above one time, yeah that failed. And let me tell you, there wasn't enough beer in the county to solve my anti-Datsun mood, after spending 3 hours attempting to get that stupid thing back in place. I finally grew up and pulled the cover, though. Which, I assume is where you're at. My personal favorite is the good old trusty BFH. If you don't HAVE a BFH, use a nice deadblow and see if that knocks it loose. If you can't get that to work, do as many others have suggested. Put it in gear and apply the ebrake. If you have a buddy, have him/her stomp on the brakes while you do it. If it turns out to be a royal supreme bizzie, grab a torque wrench and see just how hard she's on there. Pics as proof! PS avoid the license plate. They're sharper when that bolt breaks loose. ;) Quote Link to comment
DanielC Posted September 28, 2011 Report Share Posted September 28, 2011 When you put the transmission into gear, put it in fourth gear. it is one to one ratio, and does not multiply the torque you are applying to the crankshaft. Additionally, inside the transmission, it does not apply stress to the cluster gear. One way to possibly break the crankshaft bolt loose is to put a wrench that fits snugly on the crankshaft bolt, and rest the wrench on part of the frame, and secure it there. Tie it down, duct tape it, or whatever works. Then briefly crank the engine. This is best done with the head still on the engine, but we are beyond that. Quote Link to comment
620fever Posted November 23, 2011 Report Share Posted November 23, 2011 So I'm in the process of breaking my crank bolt loose as well and have been unsuccessful, I have really put a lot of torque but am still unable to loosen the bolt, even broke a ratchet that was too small for this application. I'm wondering if I've taken the head, water pump, distributor, and oil pump off, if it would be a terrible idea to do what was explain in the post above, to briefly turn the motor? Thanks. Quote Link to comment
Laecaon Posted November 23, 2011 Report Share Posted November 23, 2011 If the chain is still down there, I would not turn it by the starter. It will come out. Get a breaker bar on it. Put the truck in 4th, and pull on it hard. My method is to put my 1/2in craftsman ratchet on it and smack the ratchet with a hammer. About the second or third blow it gives way. Quote Link to comment
DanielC Posted November 23, 2011 Report Share Posted November 23, 2011 Is the engine still in the truck? Quote Link to comment
Sealik Posted November 23, 2011 Report Share Posted November 23, 2011 I had the same problem....had to remove the crank bolt after the TC was wedged, basically didn't want to turn the engine over. Pulled starter, placed a thin pry bar between flywheel and bell housing, then pivoted, just some slight pressure to hold the flywheel in place. Doesn't take much leverage. Also had trannie in 4th gear Long pipe on socket wrench.....good snap.....done Quote Link to comment
620fever Posted November 23, 2011 Report Share Posted November 23, 2011 Engine is still in truck. I'll try smacking it a few times see if it will break loose that way. Quote Link to comment
620fever Posted November 23, 2011 Report Share Posted November 23, 2011 I also plan on replacing chain and all, I have a whole new timing set, so I'm not too worried about screwing any of that stuff up. Quote Link to comment
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