Jeff Balazs Posted October 22, 2014 Report Share Posted October 22, 2014 Hey Guy's; I have a situation that I think I would like to correct. The engine in my truck has some end play in the crankshaft. It is visible at the front engine pulley when the clutch is depressed. When the engine is cold and for at least the first 10 minutes of run time there is a kind of squealing or soft rubbing sound that goes away if I spray some lube behind the pulley or step on the clutch. The engine is a 54 T342 230 mated to a fluid drive four speed. I did not rebuild it but I did have the head off to inspect the bores and it was in excellent shape. I also dropped the oil pan to make certain there wasn't any metal etc...lurking there. All looked good and I found a tag that indicated that it had been bored 30 over and the crank was at 10 under. I just cleaned everything up and buttoned it up. It runs really well and does not leak oil at all. Compression, oil pressure and manifold vacuum are all right where you would expect them to be on a fairly fresh rebuild. I also put a new timing chain and front seal on when I had the head off. It has a plain engine pulley not the dampening type. The sound I am hearing is definitely coming from the seal. I did not use a speedy sleeve but chose to polish the hub/seal surface as it was not heavily scored. In retrospect I probably should have sleeved it. So here is my question for you very savvy L6 guys....... What do you think about just dropping the oil pan and replacing the rear main bearing? Does this have any chance of being a fairly long term repair? I am just not familiar enough with the type of wear that would cause this to make a judgement call like this. What say you fellows who have done more than one crank and know what to look for? Thanks for your thoughts in advance. Jeff Quote Link to comment Share on other sites More sharing options...
Dave72dt Posted October 22, 2014 Report Share Posted October 22, 2014 If the rear main is the thrust brg, it may help. It may not be long term. Typically, the wear would be on the back side of the brg. The crank may be worn into as well and there is no cheap fix for that. Quote Link to comment Share on other sites More sharing options...
Jeff Balazs Posted October 23, 2014 Author Report Share Posted October 23, 2014 I don't have any experience at all with this type of thrust wear. Is it extremely likely that the thrust shoulder on the crank itself has worn badly? Maybe I have lead a charmed life but I have never run into this condition on any of the other engines I have owned over the years. Jeff Quote Link to comment Share on other sites More sharing options...
Dave72dt Posted October 23, 2014 Report Share Posted October 23, 2014 I wouldn't say it's common. I've run into it once, Chrysler 3.3 in a minivan with an auto trans. The replacement thrust brg for that engine had a wider thrust surface than the original had so maybe it was more common on that engine. Two wear surfaces, either or both can be affected and since you have noticeable movement, you'll need to look at both. Quote Link to comment Share on other sites More sharing options...
Jeff Balazs Posted October 23, 2014 Author Report Share Posted October 23, 2014 Dave; That is interesting......maybe it is a mopar thing? It is funny as I have just never run into anything like this before. My last truck had a 4 bolt main bearing sbc in it. 565,000 miles on the original bottom end and still going strong. I guess what I am trying to ascertain is if this condition is likely due to wear of the thrust surfaces? or if some error was made with the crank work when it was rebuilt? I had a machinist friend measure the bores when I had the head off and they were all spot on for the overbore that had been done. Just judging by the lack of wear we kind of thought that perhaps this engine had very low hours on the rebuild. That theory has been backed up by the way it runs. Other than this end play it seems very solid. If it didn't make this odd noise I would have never thought anything was wrong with it. Jeff 1 Quote Link to comment Share on other sites More sharing options...
Dave72dt Posted October 23, 2014 Report Share Posted October 23, 2014 Not just Mopar. I've rebuilt a couple other engines that had wider thrust surfaces on the replacement brgs. It is probably wear on the thrust surfaces, however, if the crank was reground at some time in it's life, it's possible to get the journal too wide when grinding. The stones used aren't wide enough to grind the entire width of the journal in one pass so it's possible to take a bit off the sides of the crank when doing them. That movement may also be putting premature wear on the rod bearings and wrist pin bushings Quote Link to comment Share on other sites More sharing options...
Jeff Balazs Posted October 23, 2014 Author Report Share Posted October 23, 2014 Yes I can certainly see how accelerated wear could happen as a result of this end play. It is definitely a concern I have. And I have never seen any main bearings available for these engines with a wider than normal thrust surface. Not sure if something like that exists for one of these engines. I am not enough of a machinist type/ engine builder to know what my next move is. I do know I don't want to tear into this and get in over my head. One of my thoughts since early on in this reclamation project has been to find another more or less identical engine and have it professionally rebuilt. Do a swap and eventually have the first engine worked over as a spare. Might be a bit over the top but I am not going to buy any other vehicles again ....so it may make sense in the long run. Jeff Quote Link to comment Share on other sites More sharing options...
Dave72dt Posted October 23, 2014 Report Share Posted October 23, 2014 The only way you'll know for sure is to drop the pan and look, either now or at your next scheduled oil change. You'll need to drop the pan and that main anyway to find out the brg size unless you looked at it earlier and recorded it. Quote Link to comment Share on other sites More sharing options...
52b3b Joe Posted October 23, 2014 Report Share Posted October 23, 2014 (edited) Our 41 Desoto had this problem. The rear cap was put on correctly. Regardless, I would pull the pan and inspect. Edited October 23, 2014 by 52b3b Joe Quote Link to comment Share on other sites More sharing options...
Jeff Balazs Posted October 23, 2014 Author Report Share Posted October 23, 2014 Our 41 Desoto had this problem. The rear cap was put on correctly. Regardless, I would pull the pan and inspect. Joe; Did you mean to say incorrectly? Is it possible that these were put in wrong way around? Jeff Quote Link to comment Share on other sites More sharing options...
52b3b Joe Posted October 23, 2014 Report Share Posted October 23, 2014 Joe; Did you mean to say incorrectly? Is it possible that these were put in wrong way around? Jeff Yes I meant incorrectly, it was on backwards. Sorry for the bad typing! Quote Link to comment Share on other sites More sharing options...
Don Coatney Posted October 23, 2014 Report Share Posted October 23, 2014 This is getting interesting. Pictured below is the rear main bearing cap on my Desoto engine. I don't think it is much different than a short 23" block rear main bearing. I don't see how this cap could be installed backwards. It looks like the insert could possibly be installed backwards but not the cap. Below is a photo of the front main bearing. It appears it may be possible to install this one backwards. 1 Quote Link to comment Share on other sites More sharing options...
52b3b Joe Posted October 23, 2014 Report Share Posted October 23, 2014 This is getting interesting. Pictured below is the rear main bearing cap on my Desoto engine. I don't think it is much different than a short 23" block rear main bearing. I don't see how this cap could be installed backwards. It looks like the insert could possibly be installed backwards but not the cap. Below is a photo of the front main bearing. It appears it may be possible to install this one backwards. Don, now I'm not sure. I thought that was the case, but now I'm not sure. I might have spoke incorrectly. I'll find out though. Quote Link to comment Share on other sites More sharing options...
Jeff Balazs Posted October 23, 2014 Author Report Share Posted October 23, 2014 Hmmm. It doesn't look to me as though the rear bearing has a different thickness for the thrust surface in Don's photos? Or maybe I am missing something. Jeff Quote Link to comment Share on other sites More sharing options...
Don Coatney Posted October 23, 2014 Report Share Posted October 23, 2014 I had to look a while to find this photo. This is a set of spare bearings that I sold to James Douglas about 10 or so years ago and he is running them in his Desoto. This may or may not help. Quote Link to comment Share on other sites More sharing options...
Jeff Balazs Posted October 23, 2014 Author Report Share Posted October 23, 2014 Thanks Don; Assuming the 23" block bearings are similar it does not look as though the rear main bearings have a thicker flange on one edge. It also looks like they index into the block and cap and can only be fit one way. Is that correct? Jeff Quote Link to comment Share on other sites More sharing options...
Don Coatney Posted October 23, 2014 Report Share Posted October 23, 2014 Indexing is correct. As I have said these are for the longer block engines. I don't have any information on the shorter block bearings but my best guess is they are similar in design. And Joe was also working on a long block Desoto engine. You might contact forum members blueskies or Joe Flannigan as we all were building engines at the same time and they may have shorter engine photos. Quote Link to comment Share on other sites More sharing options...
Jeff Balazs Posted October 23, 2014 Author Report Share Posted October 23, 2014 Ok then maybe somebody out there familiar with the short block bearings could verify this? I will have to see what I can find out. I am just a mopar noobie when it comes to this kind of detailed internal stuff. I have managed to get a pretty good handle on the truck externals in the past couple of years. I suppose it is time now I got a bit more familiar with these little engine particulars. Truthfully I was sort of hoping I could remain blissfully ignorant on this topic. And it wouldn't have bothered me a bit I got close.....so close..... but alas it seems....no cigar Jeff Quote Link to comment Share on other sites More sharing options...
Dave72dt Posted October 23, 2014 Report Share Posted October 23, 2014 The only way you could put the rear main on backwards would be if it had a bolt on rear seal for the lower half. Brgs could be swapped top for bottom and cause a problem if 1 of the 2 halves did not have an oil hole in it or backwards if the indexing tang was destroyed. As you can see in Don's photo there is no difference in the thrust flange thickness. The difference in the thicker ones I have installed in those engines were the depth those thrust flanges extended into the block and over the main cap. Some of those engines I did also had the thrust flanges separate from the main part of the brg and were available in oversize thicknesses so the thrust clearance could be adjusted. That won't apply to your engine though. Just FYI 1 Quote Link to comment Share on other sites More sharing options...
Jeff Balazs Posted October 24, 2014 Author Report Share Posted October 24, 2014 My hope of an easy-ish fix is not sounding (or looking) very promising at this point. I am starting to think that the crank itself must have been worn and not properly addressed when it was rebuilt years back. It is very hard for me to imagine that the only problem I am going to find is a laterally worn bearing shell, Especially if this rebuild has the kind of hours on it that I think it has. Jeff Quote Link to comment Share on other sites More sharing options...
Dave72dt Posted October 24, 2014 Report Share Posted October 24, 2014 Before you start tearing everything apart, why not scare up a dial indicator and get an actual reading on how much end play you really have. 1 Quote Link to comment Share on other sites More sharing options...
DJ194950 Posted October 24, 2014 Report Share Posted October 24, 2014 My 46-54 Plymouth repair Manuel pics of the rear crankshaft bearing look exactly like Don's pics. The specs on 218's and 230's are the same on the crank bearing sizes etc. are are the same car/truck as far as I know. Can you borrow a dial indicator with a magnetic base and has arms that can be positioned to touch the front crank pulley? Then after removing the flywheel inspection cover the crank/flywheel could be plied reward and the dial indicator zero out, then pry the crank/flywheel forward and watch to see- .003-.007 of total movement. Close to .003 is preferred. Plying forward then reverse should, be the same, no real reason to change, just thought the plying direction really should not matter as long as one is the opposite of the other. No removing oil pan etc. to see if you really have a problem. Suggested using the flywheel cover just in case to front crank pulley is loose/moves etc. if a pry bar is put to it. DJ 1 Quote Link to comment Share on other sites More sharing options...
52b3b Joe Posted October 24, 2014 Report Share Posted October 24, 2014 Ok, I apologize for the earlier response. In the case of our car, the inserts were not installed correct. The oil grooves were not lined up due to one reason or another, not giving proper oil, it scored the thrust bearing causing the end play. New rear inserts were installed helping the end play, and the car went another 25,000 miles with no problems. Quote Link to comment Share on other sites More sharing options...
Jeff Balazs Posted October 24, 2014 Author Report Share Posted October 24, 2014 I guess I could borrow a dial indicator and get some sort of measurement. But I am absolutely positive that there is more than .007" of movement at the engine pulley when the clutch is applied.I'd guess it is somewhere between 1/32 to 1/16. It is significant enough that I am beginning to wonder if the shoulder flange on the bearing is missing? All I can say is that it is weird. This engine has absolutely no knocking sounds....runs very good and doesn't leak a drop of oil. Jeff Quote Link to comment Share on other sites More sharing options...
Don Coatney Posted October 24, 2014 Report Share Posted October 24, 2014 Are you sure the nut that secures the front hub to the crankshaft is tight? When you see the pulley move can you see deflection in the fan belt? In another thread you mentioned that you had to remove the water distribution in chunks. You have also stated that the engine was somewhat fresh when you got it. Was the tube not replaced when the engine was freshened? Makes me wonder what else was not done when the engine was rebuilt. Harbor Freight has a 12 dollar magnetic base for a dial indicator. http://www.harborfreight.com/multipositional-magnetic-base-with-fine-adjustment-5645.html And a dial indicator for fifteen bucks http://www.harborfreight.com/1-inch-travel-machinists-dial-indicator-623.html I have one of the bases and it works well. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.