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DT361 rebuild


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I have installed the crankshaft and main bearings on the DT361.  It seems like the rear thrust bearing is a little tight.  I can spin the crank by hand, just not freely.  Will it be alright?  The crank turns freely until I tighten up #7 

I bought my bearings from Abilene Machine.  I believe they are Reliance brand bearings, .030.  Are there different thickness of  thrust bearings?  The book shows .007 clearance between the block and crankshaft, but I don't have that.  What's your opinion?

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Um.....ya. perhaps this whole post  by jmech would have been better off as a private msg.....or not at all......just sayn.  

I am an ASE certified master auto, master machinist, master H/D truck, and master School Bus Tech. Also was School Bus Tech of the year in 1998 for the United States when I took that round of test. Ha

There are many things that can cause this problem. The fact that it is free untill the cap is torqued keeps us from accepting it as a bad bearing. The answer to my question of is there end play and ho

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Thrust has to be right.

Yes, there are different size thrust bearings.  Did your crank grinder grind the thrust?  Did you even grind the crank?

Nope.  It isn't right if it's too tight.  Need to fix it. 

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No! You cannot grind a bearing, even the thrust.  It's a precision bearing! 

Get the correct bearing, or a different one.  I'd also check to make sure the #7 journal is correctly ground.

If it turns freely until you tighten the #7 cap, I'm wondering if you have a different issue.  Possible incorrect grind on the crank, bent crank, or the line bore in the block is bad.  All these would also affect thrust.

Did you plastigauge the bearings? 

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J-Mech is only wrong on one point. Yes the thrust can be surfaced. But you must be sure nothing else is wrong first. There is another issue that concerns me more. Grinding the crank. These were elotherm treated cranks. IH specified that if ground they needed to be retreated. I have seen several broken cranks after grinding only .010. Always within the first 100 hours.

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15 hours ago, TGFAIN said:

We did have the crank ground, .030.  But the thrust bearing was not ground. 

I have taken the thrust bearing out, can I grind the sides to get the clearance?

Define “grind”.  

I wouldn’t go over to the bench grinder and skim some off unless you want a easy access hole in the side of your block by the next oil change

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33 minutes ago, Bdse25 said:

Define “grind”.  

I wouldn’t go over to the bench grinder and skim some off unless you want a easy access hole in the side of your block by the next oil change

Yes. My term was surface. Precision work requires precision tools.

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this engine is going to be the death of me yet.  LOL

I just went and picked up my rods from the machine shop.  They pressed out the wrist pin bushings and pressed in new ones.  I didn't notice until I got home that they had ground the sides of the rods.  Is this o.k.?  I am posting a picture of the rods they did and another rod I have out of another motor.  I checked with a caliper and there doesn't seem to be any difference in the rods, but the bevel is gone.  Are they o.k. to use

20190207_150639.jpg

20190207_150648.jpg

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3 hours ago, TGFAIN said:

this engine is going to be the death of me yet.  LOL

I just went and picked up my rods from the machine shop.  They pressed out the wrist pin bushings and pressed in new ones.  I didn't notice until I got home that they had ground the sides of the rods.  Is this o.k.?  I am posting a picture of the rods they did and another rod I have out of another motor.  I checked with a caliper and there doesn't seem to be any difference in the rods, but the bevel is gone.  Are they o.k. to use

20190207_150639.jpg

20190207_150648.jpg

If thats all yes.

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12 hours ago, snoshoe said:

J-Mech is only wrong on one point. Yes the thrust can be surfaced. 

If you mean the thrust surface on the crank..... well, yeah.  I thought the OP was asking if he could machine the bearing.  Maybe I misunderstood him.  But I read can "I" and then he said "grind" and the picture I saw in my mind was not a pretty one....

 

Rods look fine to me as well. 

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2 minutes ago, J-Mech said:

If you mean the thrust surface on the crank..... well, yeah.  I thought the OP was asking if he could machine the bearing.  Maybe I misunderstood him. 

 

Rods look fine to me as well. 

I took him to mean the bearing as well.

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On 2/6/2019 at 7:08 PM, J-Mech said:

No! You cannot grind a bearing, even the thrust.  It's a precision bearing! 

Get the correct bearing, or a different one.  I'd also check to make sure the #7 journal is correctly ground.

If it turns freely until you tighten the #7 cap, I'm wondering if you have a different issue.  Possible incorrect grind on the crank, bent crank, or the line bore in the block is bad.  All these would also affect thrust.

Did you plastigauge the bearings? 

In addition to what you mention here I would also check cap alignment with block for and aft. If cap is a little forward or back you lose end play.

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1 hour ago, snoshoe said:

I took him to mean the bearing as well.

Well, then I'm going to disagree with you.  You can't mill off the thrust bearing.  It's coated in babbit, just like the main it is made on.  If you machined it, you would remove the babbit and be down to brass.  Machining the crank, or changing to a different bearing is the correct solution if it's too tight.  But... I think we agree it's likely a different issue.  I find it difficult to believe that it would be that tight unless there is another issue, or the thrust is oversized. 

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I'm not aware of any different thrust thickness bearings for this engine.  To me it sounds like a quality issue or machining issue with the block or crank.

For the rods, IH was good at weight matching rod sets to a particular engine.  If you are replacing one from a different engine.  If I were you I would balance them, I'm sure you can find some videos on YouTube on how this is done it is not just the same weight it is weight of the small end and big end weighing the same.

This is the reason IH had a reputation of smooth running long running engines unlike Deere who did not bother doing this step.  I have personally worked on some Deere engines and found the rods to be way off.  Now am I being picky since this is under a 3000 rpm engine compared to a V8 that runs at 8000 rpm maybe?  But I put my stuff together to last.

BTW I have a scale and also weigh the pistons on my builds and make them all the same.

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11 hours ago, J-Mech said:

Well, then I'm going to disagree with you.  You can't mill off the thrust bearing.  It's coated in babbit, just like the main it is made on.  If you machined it, you would remove the babbit and be down to brass.  Machining the crank, or changing to a different bearing is the correct solution if it's too tight.  But... I think we agree it's likely a different issue.  I find it difficult to believe that it would be that tight unless there is another issue, or the thrust is oversized. 

Feel free to disagree and if you want to start a new post I will be happy to discuss it with you. I am in agreement with everything else. In order to help this man. We need him to try a few things and report results so we can advance to the next step. The first thing I want to know is with rear cap removed and crank spinning free is there any end play?

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2 hours ago, snoshoe said:

Feel free to disagree and if you want to start a new post I will be happy to discuss it with you.

Thanks.  But I'm not interested in debating it.... or even discussing it really.  I think we agree there's probably another issue in play here anyway.  

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There are many things that can cause this problem. The fact that it is free untill the cap is torqued keeps us from accepting it as a bad bearing. The answer to my question of is there end play and how much with the cap removed would go a long way in eliminatiing some of the posibilties.

Now he is posting what appears to be a quality issue with the front main. That makes the idea of this being the bearing easier to swallow.

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I agree.

 

I'm also very concerned that he is now asking how to put pistons in, but we haven't heard a resolve to this issue, or the front main either.  Can't put pistons in if the crank is too tight.  I'm thinking Mr Fain is going to learn a very expensive lesson on engine rebuilding with this project.....

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One possibility is the machine shop did not get the radius correct when the crank was turned on the thrust journal. In that case it would tend to lock on the very edge of the bearing when torqued down. Take a feeler gauge and measure the clearance between the crank and thrust face of the main bearing with the cap off. That should give a pretty good indication of the clearance that is there. TGFAIN if you still have the old main bearings post some pictures of all of them. From the wear patterns we probably can get some ideas if the block needs line bored or not if you did not have the machine shop check that for you. J-Mech give TGFAIN some credit, he may not know exactly what he is doing but he is aware there are some issues and he is asking questions. I would venture a guess that we were all in his position when we did our first engines too. That is how we learn, by the mistakes we make. I still have the occasional question come up and I have been doing it for better than 40 years now. 

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8 minutes ago, IHC_1470 said:

J-Mech give TGFAIN some credit, he may not know exactly what he is doing but he is aware there are some issues and he is asking questions. I would venture a guess that we were all in his position when we did our first engines too. That is how we learn, by the mistakes we make. I still have the occasional question come up and I have been doing it for better than 40 years now. 

Yeah, he is asking questions.... but not giving any feedback on any solutions.  He has like 5 threads going on this engine with different questions.  He is asking in another thread how to put the pistons in, but I see no resolution on the tight crank.  He has to get the crank right before putting pistons in.  Guy is getting the cart before the horse..... like WAY before the horse.  I'm fine with giving a newbie some slack, but it seems this guy is all over the place on this rebuild.  

Yes, we learn by mistakes, but those who have learned by mistakes are here to keep others from making them too.  That's why he needs to slow down and do this in order.  Personally, I wish he would keep all the questions in one thread, and not start a bunch of new ones..... but whatever.

As far as all of us being in his shoes on a first rebuild:  Sure.  I'm sure we were.  But how many of us that have been doing it for years tried to do an overhaul with no more guidance than an internet forum??  I sure as heck didn't.  My first few overhauls were with someone with more experience there to help and consult when need be.  I personally don't think that relying on an internet forum to "learn" from or "pick people's brain" is a good plan as far as going outside an experience level on a very costly build.  It's like building a house for the first time, but only using the internet for reference.  Better to have someone involved directly for guidance.  I've been at it 20 years, and I seldom have questions.  Like almost never..... but if I do, I have guys I call.  I would never refer to a stranger online for advice on an engine rebuild.  I like to get advice from guys I know and trust.  I say that..... then I get on the internet and give advice.  Seems backwards I know.... but it is what it is.  As far as you doing it 40 years.... are you a mechanic?  Or a farmer who works on his own stuff?  Just asking so I know.....  I think there is a stark difference between a tech and guy who does it occasionally.  That's why I don't ask questions online.  Never know who is going to answer, or how much they actually know, and how much they've actually done.  (Not making fun or debating or even trying to be a dick.  It is what it is, and I'm just stating facts.)  Seen lots of guys answer questions on internet boards that have worked on one thing, one time and suddenly they think they are an expert on the machine.  It happens.  That is why I state my credentials a lot.  Not showing off, just stating I've seen a few more things than most, and have a lot of experience so that the guy reading can decide who he is going to listen to.  This board is good though.  Lots of experienced guys with good advice (for the most part) and all willing to help.  Just up to the OP to listen, and work the issue and report back to us that he resolved the issue so we can continue to help. 

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I apologize if I'm not posting correctly.  I will keep all my questions in one thread.  This is not my first rebuilt engine, 2 years experience in tractor shop and 9 years in diesel truck shop in my earlier years.   But it is my first DT361, and from what I've heard, they are in a class of their own.  I'm just trying to make certain I get it right.

The question about the pistons was for future reference.  I'm not there yet, just checking others opinions.

The question about the protruding bearing on #1 main:  Flush end to end in the saddle,  the protrusion is toward the front of the block.  It is flush inside the block.  This is just something I am double checking before assembling further.  

The crank and main thrust bearing are what bothers me.  I had to wait until the machine shop ground the crank before I could order the bearings because I wasn't sure what size I would need.  That's why I was asking if there were different thickness of thrust bearings, possibly standard vs. heavy duty.  Or do I need to take the crank back to the shop and have them recheck it.  It's 100 miles to the machine shop, oneway.

  I have put pressure on the crank both ways and am only getting .003 end play . This was after I polished the bearing.  The crank turns freely, but I'm concerned that it might not be enough when it heats up.  I've been told that it will wear down and be O.K.  But I've got a lot of money tied up in this to take a chance.

The block has not been line bored.  Can this be done after the sleeves are installed?

 

 

 

 

 

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