One way to buy yourself time between costly rebuilds is by replacing engine rings. This is not an option that exits 100% of the time, but every once in a while you can get lucky and be able to get a little more use out of an engine before a rebuild becomes necessary. The clincher is just how much of a teardown is necessary to change the rings and if at that point you might as well go all the way and finish the job. It is also possible that you might find other damages in the process that might necessitate rebuilding sooner than you hoped.
A sign of rings in need of replacement often comes in the form of excessive oil consumption or the presence of blue smoke. It is worthwhile to mention that other issues can mimic these signs, so your assessment of what is truly going on will need to be more than surface deep. For example, worn out pistons and sleeves can present in the same manner as worn out rings. Before replacing rings, you should also check cylinder bores and pistons for scoring, signs of oil leakage into cooling systems, and be sure your existing rings are not sticking.
When beginning the process of ring replacement, you will need to acquire the correct size rings. To do this, you must take into account the manufacturer\'s recommended gap and as well as measuring the bore and calculating what will fill the gap best. This sometimes translates to using rings that are an oversize up, but before making this call, consult your owner\'s manual for ring size information.
Also covered in your owner\'s manual should be the disassembly steps you will need to follow. This usually begins with the drainage of fluid and removal of the oil pan. Depending on the model of tractor you have, you may be able to remove pistons without removing the head itself and instead removing rod bearing caps. If you do not remove the head, however, you will not be able to address ridges that may have formed atop your cylinders, which can be a problem on down the road. Because of this, removing the head is the better, although more time consuming and labor intensive, option.
Once you have everything in plain sight, be sure to check pistons and cylinders for signs of scoring. Should scoring be present, ring replacement alone will not be adequate to get your tractor back to ideal operating condition. If no scoring is present, continue your ring change by removing old rings carefully. Check the gaps where the old rings rested for damage before continuing, and be sure to clean those areas before placing new rings to enable proper seating. One reason new rings might not seat properly is due to glazed cylinder bores. Through the use of a hone, you can give cylinders the coarse surface they need. A hone can be chucked into your drill and moved up and down against the cylinder to rough it up but be sure to do this carefully and do not allow the drill to run constantly against the same area of the cylinder.
New rings may require a little bit of manipulation to enable proper gap clearance. You will need to check this with a feeler gauge in order to know if the gap is correct or if it will need adjustment. The final gap value needs to correspond with your manufacturer\'s specs, so you may need to make some changes with a gap spreader to arrive at your final gap designation. When reinstalling piston rings, remember to start with the lowest ring and work your way up. A ring compressor can help with this task by enabling the compression necessary for pistons to be placed into the bore. Once the rings are in place, follow your owner\'s manual regarding engine component reassembly.
Ring replacement is a way to save the time and expense of a full rebuild, but do keep in mind that ring replacement alone may not be enough. As other problems are discovered, it could be that you wind up with engine components all over your barn that need major work before they can be put back together and expected to function normally. Because of this, it is important that you fully realize that the possibility exists for a ring job to turn into a rebuild despite your best efforts to avoid one. It is also key to keep in mind that while replacing rings may not sound too difficult, it is a highly technical job that involves working at the heart of your engine and is something that may be best done by a professional or someone with extensive experience.
It is easy to want to do it yourself and save money, and in a lot of cases that idea pans out beautifully. When it comes to ring changes, you are looking at a lot of unknowns and should be prepared for that moving forward. Ideally a ring change will go off without a hitch and buy you a fair amount of time before a rebuild becomes necessary, but don\'t ignore the possibility that the need for more work could be discovered. It is better to go into a ring change with eyes wide open hoping for the best than attempting it with the assumption that all will be okay and being sidetracked tremendously if it is not.