new/used/rebuilt engine needed for JD 4100

[MetalChicken]

I'd def. have a go at rebuilding it myself.

A couple of years ago I rebuilt the engine of my IH 484 (small ag tractor). I replaced the pistons, rings, cylinder sleeves big end bearings and had the head skimmed by an engine shop.

The rebuild was done 'in frame' and was great fun. I had NEVER done anything like that before and had little engine knowledge.
Diesels are simple beasts, all you need are a few tools and the workshop manual. Chances are the head doesn't need touching so it should be a simple ring/piston job.
If you take your time and don't try anything silly you'll fix it yourself, save a load of money and learn a lot about engines. You'll be a lot closer to your tractor after you've nursed it back to health yourself.
All you can lose is a bit of spare time and a fairly small amount of money - especially if you don't order new parts until you've got the head off and the pistons out.
I'm sure there's a lot of help waiting to be given here if you have any questions.
Take pictures of everything (to remind yourself where stuff goes and to show us!) and go slowly - it's not a race
/forums/images/graemlins/smirk.gif

 

[coloradotrout]

Yeah, I'm a glutten for doing it myself. I'll probably go the route of "in" sourcing my job.

 

[3RRL]

</font><font color="blue" class="small">( If you take your time and don't try anything silly you'll fix it yourself, save a load of money and learn a lot about engines. You'll be a lot closer to your tractor after you've nursed it back to health yourself.)</font>

Really liked what you said and how you put it. Excellent advice and certainly true.

 

[coloradotrout]

So I've scimmed the manual on pulling pistons and replacing rings. Pull muffler, pull head, drop oil pan. That's about it. Now, that said, are there any "gotcha's" along the way? When I put the piston back in, do I need to worry about timing? Or does that take care of itself as long as I don't dig deeper in the engine?

 

[MetalChicken]

Well after stripping the head, oil pan, etc. I undid the big end bearing caps (note which way round they go and labels them cos they must go back in the same place), knocked out the pistons from underneath, replaced the pistons with new ones and put them back in!
My tractor has cylinder liners so they where put in before the new pistons.
That's the simple version of it, but there are no extra basic steps involved.
The timing will remain the same uless you remove the injector pump - which you're def not going to do /forums/images/graemlins/cool.gif

Remember to keep it simple and not remove anything that doesn't need to be touched. Let me know if your engine has sleeves. If so it may be an idea to replace them (you will quite esily be able to get a kit with new sleeves, pistons and rings) as a broken ring 'may' have scratches the bore.

 

[Mike_Lipke]

Timing will not be affected. Pistons are prolly ok. Most any machine shop works on both gas and Diesels, and if you walk in with the pistons, they can usually tell you just by looking at them if they need to be replaced. I have found that machine shop guys are very helpful.
If it was overheated, and it sure sounds like it was, the head should be checked for warp and planed if needed. Simple, cheap.
Cast iron blocks are pretty darn stable, so it is prolly ok, but you can buy a dial guage, or borrow one, and check for bore out of round.
Tools are cheap, really. You will need feeler guages, ring compressor, torque wrench, dingleberry hone, metric wrenches and sockets. You prolly have everything but the rc, dbh and tw.
Get a sharpie, and label parts. Piston 1, 2, 3. Arrow toward front, etc.
Go to walmart and get 4 or 5 cans of their carb cleaner. I think they sell that for about 88cents a can, and it works well for blasting off grease and crud off most everything before reassembly. Get the bolts clean, and then lube the threads with grease, oil or antisieze so that you get good torque readings.
I'm betting all you need is gaskets and rings. They may be able to plane the head (if necessary) with the valves in it. If not, they can take out the valves, plane the head, and reinstall the valves with new oil seals. That whole business should be under $100. And, it is one less place for the oil to get into the combustion chamber. You will have to set the valves if this is done, but again, not that hard with the injectors out and no compression.
Go for it.
You will smell funny and have discolored digits, but you will have fun and really know that engine.

 

[jimmysisson]

With chassis parts and a torque wrench, the threads are not supposed to be lubed, but clean and dry. Is that not true with engine/drivetrain parts? Anyone know how antisieze affects torque readings? Or am I all wet again?
Jim

 

[Mike_Lipke]

The service manual will be the final arbiter. Most times the head bolts are so highly torqued that they can gall the threads if not lubed.
Reminds me. some engines recommend that the head bolts be replaced if the head comes off, because they actually stretch. If the manual or the dealer recommend this, don't cheat. they can break off in the block while torquing, and that is not a good thing. Don't fret about this though. If the dealer or book says to just retorque, you will be ok. Also, do it JUST the way they say. Some, you have to torque to a certain number, then rotate an additional 90, 120, or even 180 degrees. It really is fun. I am serious. Fun.

 

[coloradotrout]

As for a torque wrench, are the HF ones good enough?
http://order.harborfreight.com/EasyAsk/harborfreight/results.jsp

their 1/4", 3/8", or 1/2"

 

[Mike_Lipke]

I would think that they are fine. I have a 3/8 inch and it is a good size. 1/4 is too small. I find myself using 3/8 inch sockets most of the time, so 3/8 TW is what I use. If I am torquing something that uses one of my 1/2 sockets, I use a 3/8 to 1/2 converter so that I can still use the 3/8 TW.
Have you started tearing into that engine yet?
Find a small local machine shop to help with the technical questions. Most are very helpfull with questions like "is this piston ok, or should I buy a new one?"