streamer Posted May 9, 2007 Report Share Posted May 9, 2007 I have a 48' B1B with a 53' Plymouth engine that I believe needs main bearings. If I,m doing that I may as well do the rod bearings also. Has anyone done this with the engine in place? If so please rate the difficulty of this work. Thanks Quote Link to comment Share on other sites More sharing options...
Merle Coggins Posted May 9, 2007 Report Share Posted May 9, 2007 Has anyone done this with the engine in place? If so please rate the difficulty of this work. Thanks Well, I've not done a rod & main bearing replacement on one of these engines while in chassis, but I have done it on much larger engines. As long as you can drop the pan without too much difficulty it shouldn't be too bad. (if you don't mind oil dripping on you throughout the entire job ) I would recommend loosening all main caps (slightly) to allow the crank to drop out of the upper bearings. This will make it easier to remove the old shells and slide in new ones. Then, one at a time, remove a bearing cap, and roll the upper bearing shell out by pushing up on the non-notch side with a screwdriver or similar tool (be very careful not to scratch the crank or bearing saddle!!!) Once you get it started out, you can usually grip it from the other side and continue to slide it around the crank journal until it's on the bottom, then pick it off. Now, remove the bearing shell from the cap, clean the cap and block saddle thoroughly with solvent or Brake-Kleen (be careful of your eyes). Clean the new bearing shells and insert the cap side into the cap. Lube the crank side only of bearing shells and roll the upper shell into the block saddle in the reverse manner of how it was removed. When all bearings are replaced, torque the bolts. The rod bearing procedure is very similar. Rotate the crank to get 2 of the rods at the bottom. Remove the caps (do one at a time to reduce the chance of switching the caps on reassembly), gently push the rod/piston up into the cylinder to gain clearance between the crank journal and bearing. then it's pretty much the same as the main bearings. Just be sure that you only lube the inside surface of the bearings. The surface that contacts the block and bearing cap must be clean and dry. And, as I've said, be prepared to have oil dripping throughout the entire job. Just when you think no more oil could possible be there to drip, you'll rotate the engine for the next pair of rod bearings, and more oil will drip out. I still have t-shirts that are polka-dotted from oil drips during bearing changes several years ago. Good luck, Merle Quote Link to comment Share on other sites More sharing options...
dmulhall Posted May 9, 2007 Report Share Posted May 9, 2007 I just replaced the rod bearings in my truck (218).. it was pretty easy, but like merle said, you always have oil dripping on you, or in your hair. Unfortunity, I put it all back together and it was a little too tight and wouldnt turn over fast enough. So, I got a buddy and pull started it. I was all excited about getting it back up and running, until I noticed that the knock was still there:mad: .. now I have to pull it all apart again, and maybe check the wrist pins.. by the look of the old bearings, I thought, garenteed that it was the problem, but I guess I was wrong.. the crank was a little scared up from the junk in the oil pan, I didnt get the crank turned at all, and put standard bearings back in, maybe thats the problem? I dont know...a little frustrated now...I'm letting it sit in the garage for awhile and see if it gets sick of being in there Sometime soon, I'll get over it and start working on it again...its just easy to get overly frustrated... I really didnt want to pull the whole engine apart and re-do it...but I might have no alternative, I dont know.. does anyone know how often the wrist pins are a problem in a 218? the knock seems to "double" or probably more than one cylinder? maybe a siezing up wrist pin? I dunno...I'm not much of an engine man.. Just thinking about it, if it was that tight that I had to pull-start it, it couldnt still be the bottom end, could it? does such a thing happen that maybe the crank has flat spots? seems kinda silly, but I'm kinda grasping at air here.. Thanks to all the experienced engine guys here.. Dave Mulhall Quote Link to comment Share on other sites More sharing options...
anthonyb Posted May 10, 2007 Report Share Posted May 10, 2007 Dave, Go over to the car side and review the adventures of 'blueskies' and his engine noise and the things he ended up checking before he finally got it nailed down. I think every possible noise source was suggested along with ways to confirm or deny the source. Quote Link to comment Share on other sites More sharing options...
grey beard Posted May 10, 2007 Report Share Posted May 10, 2007 This past winter I rebuilt my B1B engine in the chassis. My engine ran well before I started. I found major slop in the timing components, so I pulled things apart from there. Mine took new pistons and rings, standard rods and mains and of course a new timing chain/gear set. The first thing to check when you pull your engine apart is cylinder bore taper. For this check you will need a bore gauge. My cylinders were only worn about .003" which is neglible. If you get up around .010" it's time to think about a rebore job. Re-ringing a worn block is a waste of time. My crankshaft was perfect, and took standard bearings with just a little extra clearance, so I shimmed each rod bg. .010" behind the insert - bottom only, and got my clearances down to new specs. If you really are going to overhaul your engine in the chassis, let it sit for a few weeks after you drain the oil to avoid the problem mess Merle mentioned. I would not use a crank that had any rough or questionable journals. Having said all this, if anyone needs a nice sweet-but-filthy engine to rebuild, I have one available for fee - you pick up at my shop. It's a 218 truck motor. LOL:) Quote Link to comment Share on other sites More sharing options...
Merle Coggins Posted May 10, 2007 Report Share Posted May 10, 2007 Reading Dave Mulhall's post brought up another point. It would be a GOOD idea to measure your bearing clearance with Plastigauge when reassembling. It creates an extra step, because the bearings have to be dry (no lubrication) to measure the gap. Then remove the upper shell again to lube it and reinstall it. This will ensure all is good with the lower end. Also, if your engine has the rope type rear crank seal, this is the time to replace it too. And as for Dave's (grey beard's) suggestion to drain the oil far in advance... It's a good theory, but it won't help much. The oil stays in the passages in the crank, and will come pouring out every time you remove a bearing cap. It will help remove any oil from the components that are normally immersed in the oil, but not the oil that remained within the oil passages. Quote Link to comment Share on other sites More sharing options...
Young Ed Posted May 10, 2007 Report Share Posted May 10, 2007 IMO its not worth it. The main source of problems with these is bad cam bearings which leads to low oil pressure and its down hill from there. Even if the pistons etc are to be reused you're still ahead to pull the engine and get it boiled out and do the cam bearings along with the rest of the bearings. Quote Link to comment Share on other sites More sharing options...
streamer Posted May 10, 2007 Author Report Share Posted May 10, 2007 Thanks for all the replies. After reading all the stuff from Blueskies and the trouble shooting of engine noises, I believe that my knock is main bearings. I have good oil presure at start up and start to lose it as the engine warms. When under real hard load, the knock is there but not real loud, however when you back off it comes back with a vegance -- no knock or engine noise at idle or not in gear. I did have some clutch chatter and found that the rear motor mounts needed to be tightned. Chatter is now gone, but engine knock is still there. I will drop the oil pan and check all the bolts on the flywheel and clutch and then all the bearings. I'll let you guys know what I find. It will be a few weeks before I get it done. Thanks again for your input, I'm sure I will have many more questions. Quote Link to comment Share on other sites More sharing options...
dmulhall Posted May 10, 2007 Report Share Posted May 10, 2007 I'm not a engine pro by any means but I think main bearing noise is usually a low, deep sounding knock that would get worse as the engine warms up. But I think you would hear it most of the time at all rpms. If it was a rod bearing or wrist pin it would get worse as the engine warms up and would knock mostly in between 1800 and 2200 rpm. I know most of our trucks dont have tachs but best judgment would do. It also is bad at an "constant rpm", not accellerating or decellerating. I dont know, correct me if I'm wrong guys, but in my limited experience thats what I've found.. Quote Link to comment Share on other sites More sharing options...
brian hood Posted February 3, 2008 Report Share Posted February 3, 2008 Use an oil pressure check. If you are dropping pressure, then you do need bearings. If your pressure holds, then its probally just an old engine noise. Brian Quote Link to comment Share on other sites More sharing options...
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