Installing a PTO on an NV5600

[JOblenes]

The next thing you will want to do is remove the bottom bolt from the PTO cover and drain the transmission. Once this is complete you can remove the cover and have a look inside. You will immediately see the large gear that the PTO will interface with. I suggest that your very next step should be to stuff the PTO opening with a clean shop rag. You should then go ahead and clean off the original PTO cover sealant (basically scrape it off with a razor blade). You are now ready to do the first difficult step, grind the transmission. The reason you need to do this is shown in the next two photos. The PTO cover is hard up against the bolting flange for the bell housing, the PTO has a boss that extends beyond the PTO cover foot print and the flange must be ground back to accommodate this (both Muncie and Chelsea have this “feature”). I used a regular 4. 5” angle grinder to accomplish this task. I also stuffed some small bits of shop rag to fill the PTO bolt holes so that the grindings would not get into the transmission. You will have to do a couple of trial fits to check if you have removed enough metal. Basically just make sure PTO can sit flat on the PTO mounting area and you can see the bolt holes centered through the PTO holes. Once this is done you are good-to-go.

 

[JOblenes]

The next step you will complete is installing the studs into the transmission. These came with the Muncie kit and were pre-coated with sealant/thread-locker. On my transmission these simply turned in by hand, no tools required. You are now ready to check the gear backlash. I presented the method for setting backlash above so I won’t discuss it further unless someone asks. Once you have gotten the play to spec you are ready to bolt it on. A word of advice I have is to determine your total shim thickness which will consist of paper gasket/metal shim/paper gasket stacked up, then go to the PTO distributor and buy this exact thickness of metal shim and use RTV silicone to seal the unit instead of the paper. As you will see in the accompanying photo of my install I have had some weeping, this is nothing to be concerned about really, there is no dripping, but just “looks bad” in my book. This is over a years worth of weeping. I was not particularly impressed with the finish of the PTO area on the transmission, there were some fairly heavy tool marks from the machining process and I was skeptical of a weep free fit with the paper gasket from the get go. The kit comes with special copper washer and locking tabs to hold the nuts in place on the studs and prevent them from loosening off. The next step is to make sure the PTO is NOT engaged and then go and start the truck, and then with the transmission in neutral slowly let the clutch out. This will spin the PTO input gear and you can listen for any weird noises that might indicate a poor backlash setting. According to Muncie it is safe to run the transmission in neutral for a few short moments to check this, I did and everything sounded good (no new weird noises), I also went one step further and went through the same procedure with the PTO shifter engaged and everything sounded good (actually I could not tell it was there, it was that quiet). At this point you can re-fill the transmission with you favorite fluid and start bolting everything back together. On my truck (’04. 5) the bolt head on top of the cable actuator was very close to the exhaust piping so I ended up taking the truck to a muffler shop and we heated that area of the pipe and used a small sledge to “flat spot” the pipe and just give a little more clearance. I will give you folks a few moments to digest all of this and then follow up with another post showing cable routing. I will then follow that up with some info on designing your hydraulic system. Here are a few photos showing the completed install, note the congestion. As you can see I did wrap the exhaust with insulation and covered the hydraulic hoses with heat shielding, though I am not positive they are required, I just wanted to avoid all problems.

 

[Rotty]

Where did you install the tank? pix if possible.

 

[rbattelle]

Wow, JOblenes, I can't thank you enough for this thread. It will serve me well one day.



How long did you let the engine run with the transmission in neutral and empty of fluid? They say "a few moments", but that doesn't mean much to me. You did that after setting the backlash, right?



-Ryan

 

[JOblenes]

Where did you install the tank? pix if possible.

There is a photo in this thread,



http://www.tdr1.com/forums/showpost.php?p=1428356&postcount=12



BAsically I crammed a 2. 5 gal. tank, pressure control valve, pressure compensated priority flow control and a rotameter (flow meter) in the area in the front of my toolbox, the hydraulic lines and filter are mounted under the bed. I will post more next week with more detailed pictures.



Jonathan

 

[JOblenes]

Wow, JOblenes, I can't thank you enough for this thread. It will serve me well one day.



How long did you let the engine run with the transmission in neutral and empty of fluid? They say "a few moments", but that doesn't mean much to me. You did that after setting the backlash, right?



-Ryan

I probably let it run for 15 seconds on 4 occasions, 1 minute total. This was done after the backlash was set properly and there was virtually no noise from the PTO.



Jonathan

 

[JOblenes]

Since I am not in a location where I am able to take photos of the truck I thought I would make a post that discusses the design of the hydraulic system. The figure below shows the system that is installed on my truck. The heart of the system is the hydraulic pump. In order to properly select your pump you must know the characteristics of the device you are trying to power. As I mentioned in the thread above I was looking to get maximum performance from my hydraulic winch when the truck was idling. To get maximum performance really meant being able to provide the maximum flowrate to the winches (3. 5 gpm) so that the winch would spool (spin) as fast as its rated for. Maximum performance also means having the maximum allowed 1500 psi available. However, the pressure criteria is almost secondary, it does equate to the amount of “pull” the winch will have, but 1500 psi is quite low compared to what the typical hydraulic gear pumps will put out (the pump I chose has a maximum continuous pressure over 4000 psi). Most hydraulic pumps are specified with a volume per revolution typically in cu. in. /rev. To determine how big a pump you need you simply take your desired flowate in GPM/ convert to cu. in. /min then divide by your chosen PTO shaft speed in RPM to get the cu. in. /rev. I would take this value then go about 20+ % bigger to ensure you have enough pump (the pumps are not 100% efficient and the cu. in. /rev specification of the pump starts to drop at maximum pressure). Of course some back and forth may be needed on the PTO gear ratio and pump size to get exactly what you are looking for.



Basically my system draws fluid from a 2. 5 gal steel reservoir that is mounted in the bed of the truck. The discharge from the pump then flows through a pressure relief valve that is set to 1500 psi (the maximum pressure allowed by the winch). This is set using a gage teed into the line. The excess fluid from the pressure relief valve is returned back to the tank. The fluid from the working port of the pressure relief valve then goes to a pressure compensated priority type flow control valve. This is the magic part of this system, basically as long as there is an excess flowrate at the inlet port to this valve the outlet flowrate on one of the ports will be controlled to a constant flowrate (set by the control knob) and the difference will flow out a second port, which I return to the tank. This is the device that will allow me to rev my engine, which speeds up the pump and pumps more fluid, but splits off anything more then the desired 3. 5 gpm that I send to the winches. The way I know that I am getting 3. 5 gpm is that the fluid then flows into a rotameter (flowmeter). I actually lied a little in a previous posts, my pump actually produces around 3. 75 gpm at idle to ensure there is always the minimum 3. 5 gpm for the winch. From there the fluid flows to one winch, then the next winch then through an oil cooler. I installed a B&M Supercooler between the charge air cooler and the radiator. The reason I did this is that I violated one of the rules-of-thumb for hydraulic systems which says that you should have a tank that is twice as large numerically as the desired flow rate, i. e. for 3. 5 gpm flow I should be using a 7 gallon reservoir. The size of the reservoir is what normally helps to provide sufficient cooling, in absence of that volume I decided to install the cooler. From there the fluid flows through a 20 micron oil/water separator oil filter before returning to the tank. If you walk into any particular hydraulic shop you will get all kinds of arguments about where to install the filter, pre-pump or pre-reservoir. Ideally you would use both. The problem with suction side (pre-pump) filters is that their capacity is about 1/3 what the same filter can accommodate on the discharge side. Apparently it makes a difference to the filter whether fluid is being sucked or pushed through the filter (though I am not sure why). So you need to go with a much larger filter on the suction side, I did not want a huge filter and therefore went discharge side (pre-reservoir). There is a down side to doing it this way including allowing any dirt in the tank to circulate once before it is caught by the filter.



I am currently downloading the catalog that I selected my components from and I will post pictures/specs for them so you can “see” the components in the system. As they are mounted on my truck they are all crammed in so tight I can not really show them.

 

[rbattelle]

I can't believe the B&M cooler handles the pressure (even though it's mounted after the work has been done by the fluid, thereby dropping pressure below 1500 psi). Any idea what the pressure is at that point in the flow?



-Ryan

 

[jrobinson2]

If the system is set up properly the back pressure on the return line will be at or below what the bypass in the filter/filter head is set at, usually 8-12 PSI, its a direct dump into the tank so the filter is the only thing to raise pressure.

 

[JOblenes]

Back Pressure

jrobinson2 is correct. The B&M cooler is rated to 200 psi and according to the folks at B&M can easily handle the 3. 5 gpm. The gage on the filter head shows that the upstream pressure at the gage is right around 20 psi. Other than the filter head there are no restrictions (line losses excluded) after the cooler and its a straight shot to the tank.