|
jdemaris
09-02-2006 06:49:40
|
|
Re: Re-building JD450, 4-202 diesel engine. in reply to John Wood, 09-01-2006 18:26:33
|
|
| |
New rod-bolts are certainly good insurance. I must admit though, that we rebuilt many of those engines at the several Deere dealerships I worked at - and we NEVER replaced the rod bolts - and I have never seen one break in that particular engine. In regard to the rear-main seal - it can be changed without the Deere service tool - but you're much better off using it. That is, unless you've got a very old engine. The first engines do not have that type of lipped-seal - the setup in the early 350s and 450s is entirely different. A "face" type seal is used. In your engine - it is extremely important that the balancing shafts and bushings are perfect. Since they are not "in frame" servicable items, they often got neglected in quick engine jobs. If they are worn - the engine will not hold good low-RPM oil pressure once it gets good and hot. Also, the engine-oil-pressure regulator valve and seat is often badly hammered and should always be replaced. In regard to the cylinder head - make sure the valve-head recess is correct. I've seen many engine jobs get screwed up because of a bad valve job. Unlike a gas engine, in this paricular diesel - the depth of the valve-head in the head is critical. If the seats and/or valves get ground, they sit lower, and poor cold starting, skipping, and smoking will result. We usually did our own valve work, but I've seen many - that were done out-of-shop get screwed up. Also - the fuel injection pump. If it's a C series pump, and it runs okay, leave it alone. But, if it's a DB or JDB - now's the time to go through it and make sure the drive bushing and seal area is good, and the internal governor dampener is updated or replaced, and also the fuel-pressure regulator stop. If the pump is old and/or has high hours and it IS a DB or JDB, it will crap out soon - and/or the timing-advance won't be working properly. You also mentioned the injectors being serviced. I'm not sure what that means. The pencil injectors are not rebuildable. They can be cleaned up a bit, and reset - but that does not extend their service life. For the most part, they are "throw away and buy new" injectors. Paying to have them serviced is usually a waste of money. I was a Roosamaster bench technician, so I know a little about it. Having them checked and ascertaining that they are in good shape is a different story. If they check out good - then you're fine. But, put new teflon seals on them and make sure you use Never-Seize or equiv. when you put them back in.
|
|
|
