Please help me optimize this document on rebuilding force tilt/trim systems.<br /><br />I recently rebuilt both of my assemblies. Unfortunately, getting ALL of the seals meant buying many hundreds of o-rings just to get seven or eight that mercury doesn't offer. So I'm dumping the excess on ebay and want to type up a small guide for buyers. What follows is the first draft. Please offer any advice, suggestions, and other issues that you think should be dealt with. If anything is confusing please assist by letting me know. Thanks in advance.<br /><br />******************************************<br />******************************************<br /><br />Purpose of this document:<br /> You should have a shop manual and refer to it as your primary guide. This set of instructions is not intended to replace a shop manual. This set of instructions is intended to assist you by dealing with issues not normally covered in a shop manual. <br /><br />Overview: <br /> Rebuilding your power trim and tilt system is usually a matter of disassembling, removing old seals, cleaning, installing new seals, and reassembling. The use of brake hones to smooth the surfaces is recommended but not usually required. During the process of rebuilding take care not to distort or scratch the internal cylinder walls. Before and during reassembly take care to keep all internal parts clean and free from dirt, dust, lint, or other debris. Apply a thin coat of marine trailer grease or vaseline to lubricate parts prior to assembly. Use automatic transmission fluid or non-detergent motor oil as your hydraulic fluid.<br /><br />The pump motor and valve:<br /> It is doubtful that either of these is bad. In normal application the pump motor will last 10-20 times longer than your outboard engine. The valve is constructed with ball bearings and springs and should outlast the motor. A simple cleaning and flushing is usually more than adequate. Taking the valve body apart is usually a mistake. However, the motor has steel components and may shown signs of rust. If the inside of your pump motor has rust then it should be cleaned. If you suspect internal rust, then you should remove the four screws securing the valve body and turn the motor shaft by hand. It should turn smoothly. If it has any grinding or makes noises like there is sand on the inside then you should disassemble, clean, and treat the motor by removing the two top screws. Before disassembilng make alignment marks between the brush cover and collar. When reassembling the motor use a fine strand of wire to hold the brushes in place while you place the armature into the cap. While holding the armature steady with one hand lower the collar into place.<br /><br />Common problems:<br /> Wherever stainless steel and aluminum come into contact there will probably be corrosion. Two dissimilar metals will act like a battery. Exposure to salt water or acid will accelerate the process. The softer metal will corrode more rapidly and the harder metal less rapidly than normal (this is the purpose of your zinc anode). The hydraulic lines and shafts of your trim system are made of stainless steel and it is not uncommon for them to be seized into place. The stainless components are easily replaced whereas the aluminum components are not. Take care not to damage or distort your aluminum components. If you are forced to cut or damage a component, then be sure to cut or damage the stainless components only.<br /><br />General procedure for working with seized components:<br />Heat and PB-Blaster penetrating oil. Use a propane torch to heat the threaded component. As it expands into the hole it will push and crack the corrosion. As it cools off the penetrating oil can work its way further into the thread. Tighten and loosen the bolt to help the oil work its way further into the thread. Repeat as many times as your patience will allow. The local hardware store should carry tri-flame torches and map gas canisters. Both can deliver significantly more heat than a standard propane torch. Take care not to distort or melt any of you aluminum parts.<br /><br />Hydraulic lines:<br />When working with hydraulic lines there are two red lines that you do not want to cross. Do not, under any circumstance, damage the aluminum (female) threads of any hydraulic joint. Do not round off the flare nuts. If your any of your hydraulic fittings are seized and you can not work them free then simply cut the tube as close to the fitting as possible. Then use a six sided socket to remove the fitting. Force will charge you $35 to $40 per replacement SS hydraulic line. You can get the same or better from the automotive inustry for about half the price. Save your old tube to use as a bending reference in the future. Replace damaged tubes with stainless or kunifer tubing of either 3/16 or 1/4 diameter. I prefer kunifer as it will result in less system corrosion than stainless. The tube lengths are 2 @ 18, 1@15, and 1@ 12. The fittings should be stainless steel. They fitting type is the same as used on an automobile - male inverted flare nuts with 3/8-24 thread. Have a professional make the tubes to your length with a double flare connection. Summit Racing has a website where you can buy the flare nuts.<br /><br />Shock bushings:<br />The force shock bushings have an aluminum collar that commonly seizes to the stainless shaft. Sacrifice the bushing before causing damage to your tilt/shock shaft or cylinder. If neccesary, use a drill or roto-tool to turn the rubber into swiss cheese. Do not try to force the shock-eye past the end of a sezied bushing or bushing shaft. <br />Force will charge you $28ea for replacement bushings. You can also use an energy suspension #98116 polyester shock eye bushing ($5 per pair) or a pair of nylon sleeve bushings. Use a serated knife to cut the polyester bushing to proper length. Install it into the shock-eye and then use a drill to make the hole clean at 9/16. You will need a drill press to make the nylon bushings.<br /><br />Trim mounting shaft:<br />This is probably the worst problem that you can encounter. There is a lot of aluminum in contact with a lot of stainless. In some cases it even becomes neccessary to remove the engine. If you have to sacrifice a part then make it the stainless mounting shaft. You can replace it with a 5/8 aluminum shaft for under $20 and less future corrosion. In the meantime heat the shaft, spray pb-blaster, let it cool, tap it with a punch, and repeat 20 times.<br /><br />Trim cylinder cover:<br />Cut the bolts, remove the cover, remove the cylinder sleeve, use heat, and replace with socket head bolts. Avoid damaging the threads in the cylinder body and under no circumstance bend or distort the cylinder sleeve.
