questions about rebuilding three ram trim system

[redbandit98]

Well, my trusty old trim system on my 85 XR2 started leaking by. Instead of rebuilding it, I just bought a used one. Well, long story short, it leaks down. I have aquired an oring kit, a repair kit, and a check valve kit. The question I have is with the port side trim ram. Without taking it apart, I'm having a hard time understanding where exactly the check valve is. Looking at the parts breakdown I found online, it seems the check valve is internal to the piston? I see that there is a check valve in the main (tilt) ram also. I found an online service manual and it states to not replace the check valve in the port side ram, you must change the ram. What is the "check valve repair kit" I bought for then, just the valve in the tilt ram? I have to take the unit to work to get the correct size spanner wrench to get the caps off. I also noticed there is a "guide" removal tool, do I need this piece? If so I can probably fabricate one. I was mainly just concerned with the ram. Although I don't want to spend the 150 on a new ram, Im going to completely go through the rest of the system so if this does indeed need to be replaced if the check valve is bad, I will go ahead and order one. I also am planning on upgrading to the two wire pump/motor as I have been advised to do. Thanks for any help.

thanks

 

[redbandit98]

Re: questions about rebuilding three ram trim system

Anyone? I got the unit half tore down. It seems a shame I can't / not supposed to remove this check valve in the port side ram piston. Seems I could count the turns of the screw and remove the valve and get it back pretty close to where it was. That or use a depth mic on the screw and set it back to that.

 

[aussieflash]

Re: questions about rebuilding three ram trim system

You cant replace check valve on port trim rod.Just clean with solvent and compressed air dry.Some rods have mesh screen on base,unscrew and clean same way.
I didnt use guide tool,just lined it all up and well lubed with trans fluid and gently tap back in.
While its apart replace all seals and orings,especially in all three caps and manual release plug.

 

[redbandit98]

Re: questions about rebuilding three ram trim system

You cant replace check valve on port trim rod.Just clean with solvent and compressed air dry.Some rods have mesh screen on base,unscrew and clean same way.
I didnt use guide tool,just lined it all up and well lubed with trans fluid and gently tap back in.
While its apart replace all seals and orings,especially in all three caps and manual release plug.

Thanks. Ill probably just pull the orings off and let the piston sit in some b12 chemtool. I have a full rebuild kit for both trim and main ram.

 

[aussieflash]

Re: questions about rebuilding three ram trim system

Dont forget to move the cup base inside main ram.You will need an air gun for that...very messy if you aint ready for it...lol.

 

[redbandit98]

Re: questions about rebuilding three ram trim system

Just to cure my own curiosity since it will be a few days before I tear the rest of it apart.. In the main ram does the check valve assembly really use all of the parts in this kit I have. It has like 10 springs and several balls, some little bitty ones and some bigger, and a few other pieces. Just curious if it really was that much to it, or was just a " generic" kit from mercury where you pick out what you need for your model.

 

[aussieflash]

Re: questions about rebuilding three ram trim system

Yes it does have a lot of springs and ball bearings.I doubt it needs replacing.Usually just a good clean.I just got the seal kit,didnt need to replace any parts.The manual has the full procedure,it can get tricky.

 

[RRitt]

Re: questions about rebuilding three ram trim system

Just to cure my own curiosity since it will be a few days before I tear the rest of it apart.. In the main ram does the check valve assembly really use all of the parts in this kit I have. It has like 10 springs and several balls, some little bitty ones and some bigger, and a few other pieces. Just curious if it really was that much to it, or was just a " generic" kit from mercury where you pick out what you need for your model.

in general .....
the ball bearings are precision chrome balls. they last almost forever in a perfect world. in real world they get rust spots from water intrusion and should be replaced whenever and wherever possible. same with springs.
other parts such as pistons, cylinders, sleeves, and caps should never have any metal to metal contact. Every moving surface should be a Buna, Viton, or urethane plastic sliding against a metal. Unless the system malfunctions the metal will last forever. The main exceptions to metal lasting forever are the pump gears and the manual release valve. if the gears run dry they can burn and ruin both the gears themselves and/or the gearcase housing. the mrv is often a threaded metal part. If overtightened they can damage the seat, snap, or wallow. An important part of trim repair is to inspect the sealing nature of MRV and make sure that it will form a pressure tight seal without needing excessive torque.

the final item of trim is the electric motor. rotted electric motors with bad seals are a main source of water intrusion. Water is your enemy. it is a waste of time to rebuild a trim system and then put on a leaky or questionable motor. running a ground strap directly from a motor bolt to an anode can often increase lifespan of trim motor by 30-50%. if the cable jacket is cracking or frayed then hunt down some 4:1 shrink ratio heatshrink with adhesive lining. The adhesive lining is critical. it melts and forms a waterproof seal.

given all of the above, seal kits and poppets will usually make a system ready to go another 15-20 years. do not hone the cylinders, they should still be new on inside. avoid cheap orings like the plague. go to grainger or industrial hydraulics shop and buy the good stuff. Viton (or BUNA) for internals. Urethane (or BUNA) for externals.

 

[redbandit98]

Re: questions about rebuilding three ram trim system

Thanks..I have actually gone through everything but the main housing. I have to take it to work and run it through the parts washer. My unit must have pre-dated the service manual I have. My manual states the tilt ram check valve is held together by either a nut that is threaded on the rod, or a bolt thats threaded into the rod. Well, mine was held on by a spanner nut. I actually took it to my local hyd shop and let them take it off. My vise jaws are half shot and I could not grip the assembly good enough to break the nut free. I also didnt want to beat the crap out of my spanner wrench. I went ahead and replaced all the springs and balls on the check valve since I did have the kit. Put new scraper/seals on all three caps. The only thing thats bugging me is the dang port side check valve. Im wondering how this thing is set at the factory. The manual states DO NOT REMOVE IT...replace entire ram if bad. This seems stupid to me. I know its because its set at a specific pressure, but how do they set this? They must have a jig or something they use to measure the psi. That or they set the screw at a specific torque setting they are not giving out. Its just a spring and a ball, I still believe that if I count the number of turns, It should be close enough...maybe Im wrong. Ill just put it back in and see what happens. Worse case I have to buy a new ram. Having done it now, I realize it would take no time at all to replace it on the boat. I also bought a new motor/pump and upgraded to the two wire system. Thanks again

 

[aussieflash]

Re: questions about rebuilding three ram trim system

Hey redband,I sent pm.Just checking you removed base cup from main ram.It has to be done with air gun.