Paulieflyer2 Posted July 23, 2011 Share Posted July 23, 2011 I have designed a jig to repair crankshaft rod journals inframe.Mine was 0.016 out of round,and aproxemntly 0.003 out of taper,I now have it .002 out of round and 0.000 taper.After the final cut I belive I can get it very close to Mack specifications witch is 0.00035. Quote Link to comment Share on other sites More sharing options...
theakerstwo Posted July 23, 2011 Share Posted July 23, 2011 I have designed a jig to repair crankshaft rod journals inframe.Mine was 0.016 out of round,and aproxemntly 0.003 out of taper,I now have it .002 out of round and 0.000 taper.After the final cut I belive I can get it very close to Mack specifications witch is 0.00035.There was a man here years ago that who grind rod jouranls in the engine. Never saw him grind a mack but many cummins and non who last more than a few months and who break the crank. Mack and i know cat is different but for years if a cummins spung a rod brg it was over with for that crank. The metal was too hard after the failure.On yours what was the cause of being out of round? Also what are you going to do with the metal cuttings. There is no way to keep them out of the engine and also if the engine has had a brg failure the engine is loaded with the metal. The galley will have metal in it till it is vatted. The oil cooler is loaded and needs at the lest pulled and cleaned but maybe replaced. The oil pump has pumped metal also and it now has wear on it as well as the relief plungers may have metal hanging them open.Sounds like you may be building a time bomb. But good luck with it. 1 Quote glenn akers Link to comment Share on other sites More sharing options...
Paulieflyer2 Posted July 23, 2011 Author Share Posted July 23, 2011 There was a man here years ago that who grind rod jouranls in the engine. Never saw him grind a mack but many cummins and non who last more than a few months and who break the crank. Mack and i know cat is different but for years if a cummins spung a rod brg it was over with for that crank. The metal was too hard after the failure.On yours what was the cause of being out of round? Also what are you going to do with the metal cuttings. There is no way to keep them out of the engine and also if the engine has had a brg failure the engine is loaded with the metal. The galley will have metal in it till it is vatted. The oil cooler is loaded and needs at the lest pulled and cleaned but maybe replaced. The oil pump has pumped metal also and it now has wear on it as well as the relief plungers may have metal hanging them open.Sounds like you may be building a time bomb. But good luck with it. Quote Link to comment Share on other sites More sharing options...
rhasler Posted July 23, 2011 Share Posted July 23, 2011 Have to agree with Glenn. If you take the radius out of the fillet area on the crank it will produce a stress riser and cause the crank to snap. Quote "Mebbe I'm too ugly and stupid to give up!" Link to comment Share on other sites More sharing options...
Paulieflyer2 Posted July 23, 2011 Author Share Posted July 23, 2011 Thank you for the reply,you are very right,and I do agree with you,I am using lapping compound of various grits witch I clean,it's only on the journal itself,The hole is pluged so none gets in there.The failed because Mack reman center put standard rod bearings,in a crank that was cut 0.010,the mains are correct,so they are fine. There was no blueing or discoling of ant sort,it only ran for a few minutes after it failed.I alreadey cleaned the oil cooler,pressure wasing rinsing with solvents and compressed air.I want to flush with solvent through top of the motor first,then I will do the bottom with solvent under pressure moving the pistons and cam to diffrent positions,blowing it out and redoing it again until I feel it's alright,I will put break in oil in for the first few hours,then change it,and new filters of course,new oil pump to. what do you mean by "The galley will have metal in it till it is vatted" I don't get this could you Please explain this more so I can try and correct it. Thank You very much Paul I will take any help I can get on this,if anybody has some suggestions,I would love to hear it Quote Link to comment Share on other sites More sharing options...
Paulieflyer2 Posted July 23, 2011 Author Share Posted July 23, 2011 Have to agree with Glenn. If you take the radius out of the fillet area on the crank it will produce a stress riser and cause the crank to snap. Quote Link to comment Share on other sites More sharing options...
Paulieflyer2 Posted July 23, 2011 Author Share Posted July 23, 2011 I am not shure what you mean by this Quote Link to comment Share on other sites More sharing options...
theakerstwo Posted July 23, 2011 Share Posted July 23, 2011 I am not shure what you mean by this It had a brg failure is what i understand so it was run long time to wear the crank bad enough to have to grind it. That means the crsnk surface has been hot so that changes the rockwell hardness and there is a place for it to break if it does. The metal from the old brg will be picked up by the oil pump and pumped thru the lub system even tho the filter should catch the metal but it may not and good way to find out is pull the rest of the brg and see if they dont have some streaks in them from metal running thru them.The reason i have said anything is i have seen this dream tryed many times and the second go around ant nice. If it spins a main brg the next time due to metal in the system then it could cause you to lose the block.In 01 DD 60S engine had a piston problem of debonding and it came apart and would break the liner and head as well in many cases blow side of block out. Under waranty DD would say replace the liner head and clean the system. If the metal in the pan was in large chunks things could be cleaned but if the driver drove the truck for a long time after the piston came apart the liner would be ground into small shavings. You could wash the system over and over and change the oil cooler which they did not want to do and still you could exspect a brg failure some time later. Then it gets a new engine.Arrow trucking here that went out of bussiness a couple years ago had their own wrecker and one driver hauling around the clock for maybe one year these trucks back home untill the last batch of trucks was repair or engine replace due to metal in the oil or a piston debonding and venting the block.I under stand trying to keep from replacing the crank so keep us informed on what happens. Quote glenn akers Link to comment Share on other sites More sharing options...
Rob Posted July 23, 2011 Share Posted July 23, 2011 Twice I've seen this done to a Cummins powered truck that was shortly on the dealer's lot that had the service performed, priced at retail. Can't say if there is any mention of this during the sale but would prolly venture to say nothing more than a bearing "roll in" was performed. Customer beware is what this tells me.Rob Quote Plodding along with no job nor practical application for my existence, but still trying to fix what's broke. Link to comment Share on other sites More sharing options...
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