Hydraulic winch repower

[Master Yota]

I will admit that my understanding of hydraulic power is rather limited, and after searching for several days, I will post my question to the esteemed guru's of this board.

To make a long story short, I need to repower my LU4 winch from shaft driven to something else as my steering linkage crosses directly infront of the PTO shaft hole in the front crossmember now that I've converted over to cross over steering.

I am considering a hydraulic motor (driven from the PS pump) to accomplish this. I have an understanding of the necessary valving, lines, and resevoirs, and such to do this, but I am at a loss for the size of the motor needed to drive the winch. Here is the info that I need:

How big does the hydraulic motor need to be (displacement)? Part numbers or specifics would be very helpful.
How much torque should the motor generate? - Keep in mind I don't want to break the winch!
How fast should the motor turn (RPM)?

I've already got a high performance pump capable of 1800psi and 4gpm which is more than what Mile Marker requires for thier winches (3.5gpm@1500psi).

Thanks for the help!

[MSeriesRebuild]

I will admit that my understanding of hydraulic power is rather limited, and after searching for several days, I will post my question to the esteemed guru's of this board.

To make a long story short, I need to repower my LU4 winch from shaft driven to something else as my steering linkage crosses directly infront of the PTO shaft hole in the front crossmember now that I've converted over to cross over steering.

I am considering a hydraulic motor (driven from the PS pump) to accomplish this. I have an understanding of the necessary valving, lines, and resevoirs, and such to do this, but I am at a loss for the size of the motor needed to drive the winch. Here is the info that I need:

How big does the hydraulic motor need to be (displacement)? Part numbers or specifics would be very helpful.
How much torque should the motor generate? - Keep in mind I don't want to break the winch!
How fast should the motor turn (RPM)?

I've already got a high performance pump capable of 1800psi and 4gpm which is more than what Mile Marker requires for thier winches (3.5gpm@1500psi).

Thanks for the help!

You need more info on pump output, such as what rpm the pump must turn in order to put out the flow and psi you mentioned. For winch operation the pump needs to be capable of delivering the needed output at a relatively low rpm. A pto operated pump would be far better for powering a winch drive motor than a power steering pump. Another consideration you'll need to look at seriously is oil capacity. Small reservoirs holding little oil are not generally suitable for this type of high torque operation, if the oil supply is not sufficient, the system will seriously overheat in a very short time. Hydraulic systems generate lots of heat in short order, the more load that is applied, the faster it happens. Unless you have a pump/motor combo that is of premium quality with options like viton seals, pushing it over around 150 degrees for any length of time will bring about oil leaks and component failure quickly.

There are formulas for calculating the need of hydraulic versus mechanical drives, (none of which I have access to at this time). I would start by comparing what you expect from the hydraulic system to the original mechanical drive system capability.

Another issue is cost, I can tell you now that a reliable hydraulic system capable of offering the desired performance in such an application won't be cheap. Personally what I would do is pto and shaft drive it. I know you said you can no longer go through the hole in the cross member because of the steering, but you can route the drive shaft under the cross member and back up to the worm shaft using u-joints and shaft supports. We have done it in some applications, it works great for way less $$ than alternatives without sacrificing dependable mechanical ability. I would much prefer it over hydraulics.

[Master Yota]

Thanks for the input Charles, as usual, you've presented some good food for thought.

The power steering pump that I have is designed to run not only the steering box but also a hydraulic ram assist cylinder as well. It is designed to generate peak flow and pressure, at or near idle to allow for larger tires to turned at low tire pressures. Its also a remote resevoir pump, the resevoir being close to 1.5 quarts of capacity. I've already added an external cooler to the mix as well to combat possible high temperatures.

I would need to ask what the stock M37 pto specs are, rated output, rpm range, available output torque, ect. before I can determine what hydraulic motor best suits the winch. I had looked at the specs for the Mile Marker hyd. winches, and found some clues, but no direct information on what they use for motors, other than the 5.9ci or 6.2ci displacement, and a minimum of 1500psi @ 3.5gpm. I also discovered that their winches are geared slightly deeper (35:1 vs. 29:1 for the LU4). They offer both a worm and planetary drive hyd. winch - so I know that it can be done. There is also some info on Bradens website about a hydraulic powered winch, but it is also not forthcomming about the motor used.

I've spent a good couple of hours staring at the problem in the garage, and had considered moving the shaft to run under the support. The only problem being the up and down movement of the drag link as the suspension cycles, and the side to side movement of the pitman arm as the box steers. I don't feel there is enough room to keep the drag link from touching the pto shaft as the suspension drops. I have a dropped pitman arm that would work, but I would need to limit the uptravel of the suspension so much that it would be riding on the bump stops over tar strips and road dips too keep the pitman off the leaf springs.

I think hydro would be the best way to solve the problem, given the nature of the dilema...

[Master Yota]

Found this particular model from Char-lynn here: http://www.bonzerhydraulics.com/Chief-C ... p_226.html

4.9ci, 715rpm, 1300 torque (unkown if thats foot pounds, or inch pounds) at 1800psi.

Do these specs (rpm and torque output) come anywhere near the stock PTO output?

[MSeriesRebuild]

Thanks for the input Charles, as usual, you've presented some good food for thought.

The power steering pump that I have is designed to run not only the steering box but also a hydraulic ram assist cylinder as well. It is designed to generate peak flow and pressure, at or near idle to allow for larger tires to turned at low tire pressures. Its also a remote resevoir pump, the resevoir being close to 1.5 quarts of capacity. I've already added an external cooler to the mix as well to combat possible high temperatures.

I would need to ask what the stock M37 pto specs are, rated output, rpm range, available output torque, ect. before I can determine what hydraulic motor best suits the winch. I had looked at the specs for the Mile Marker hyd. winches, and found some clues, but no direct information on what they use for motors, other than the 5.9ci or 6.2ci displacement, and a minimum of 1500psi @ 3.5gpm. I also discovered that their winches are geared slightly deeper (35:1 vs. 29:1 for the LU4). They offer both a worm and planetary drive hyd. winch - so I know that it can be done. There is also some info on Bradens website about a hydraulic powered winch, but it is also not forthcomming about the motor used.

I've spent a good couple of hours staring at the problem in the garage, and had considered moving the shaft to run under the support. The only problem being the up and down movement of the drag link as the suspension cycles, and the side to side movement of the pitman arm as the box steers. I don't feel there is enough room to keep the drag link from touching the pto shaft as the suspension drops. I have a dropped pitman arm that would work, but I would need to limit the uptravel of the suspension so much that it would be riding on the bump stops over tar strips and road dips too keep the pitman off the leaf springs.

I think hydro would be the best way to solve the problem, given the nature of the dilema...

It can be done for sure, but I don't think you will like the cost of putting a reliable system in place. A 1.5 quart oil capacity is no where near enough for such a system, just imagine 1.5 quarts traveling at 4 GPM under 1800 PSI, man that is faster than the speed of light. The oil would be cycling through the system so fast running a motor that over heating would reach severe levels very quickly. You have to realize pumps are designed and set up with specific operating circumstances in mind. Steering systems are about as simple as it gets, the pump is doing absolutely nothing until you turn the steering wheel. The nature of steering places only moderate stress on the system, then it goes right back into the neutral mode. This is why pumps and oil capacities are very small in steering only set ups. When you add more serious demands such as constant running a motor, you have a very different situation. Say for instance you were running the motor to reel in a load for 150', how long would that take? Lets say 5 minutes for example. With 1.5 quarts of fluid in the reservoir, that would so severely over heat that you would never make the 150' pull before catastrophic failure occured. For this type of application, you would need a reservoir with several gallons of oil capacity in order to have the needed flow rate, yet give the oil a little cooling time in the tank before it gets sent through the system again. Coolers are certainly a plus, but lets be realistic, with 1.5 quarts of oil in the reservoir, it ain't happening.

My suggestion would be to consult with a tech person experienced in industrial hydraulics. We deal with Custom Hydraulics and Design in Charlotte, NC. My go to guy is Michael, I don't have their # here now, but you can get it from directory assistance I'm sure. They are located on Statesville Ave. Trust me, he will bring up issues that never crossed your mind, it will help you see clearly to design the system that will perform reliably to meet your needs.

[Master Yota]

Your point about the size of the resevoir Charles is very valid. My only counter to that would be; How does Mile Marker do it with their winches? The typical GM saginaw power steering pump has a resevoir that holds mere ounces, and they tout that their system will pull all day long with no overheating issues. I feel that your idea to speak with a professional is the best plan so far. As for the size of my current resevoir, thats what was recommended for the pump.

I suspect that the amount of heat generated by the pump/motor will be directly related to the amount of work it needs to do. Simply winding in 150' feet of cable with no load shouldn't generate enough BTU's to cook anything. The wonderful thing about hydraulics is that it should, in theory, stall out if the load is too heavy, thus averting a thermal meltdown.

At least in a perfect world...

So resevoir size aside, Charles would you happen to have any info on the PTO specs?

[MSeriesRebuild]

Your point about the size of the resevoir Charles is very valid. My only counter to that would be; How does Mile Marker do it with their winches? The typical GM saginaw power steering pump has a resevoir that holds mere ounces, and they tout that their system will pull all day long with no overheating issues. I feel that your idea to speak with a professional is the best plan so far. As for the size of my current resevoir, thats what was recommended for the pump.

I suspect that the amount of heat generated by the pump/motor will be directly related to the amount of work it needs to do. Simply winding in 150' feet of cable with no load shouldn't generate enough BTU's to cook anything. The wonderful thing about hydraulics is that it should, in theory, stall out if the load is too heavy, thus averting a thermal meltdown.

At least in a perfect world...

So resevoir size aside, Charles would you happen to have any info on the PTO specs?

I'm not saying the size of your reservoir is wrong for a steering system, in fact it is very typical in that application.

How does mile marker do it, you'll have to ask them that one. I've just shared a little of my hydraulic experience with you, that has been small fluid capacity and heavy load equals heat. Winding in 150' of cable with no load is one thing, you certainly can't base a system on a no load capacity and expect it to perform wnen you need it too. Neither do you want to design a system that will stall before it gets the job done, at stall and just before is when heat rises quicker than any other time. Ideally you want to design your system to pull the rated capacity of the winch without stall, otherwise you won't have much when you get done.

Another issue that doesn't wash with me is the fact you say mile marker says their system will pull all day without over heating. I never saw any Mile Marker product that impressed me, and I just don't believe that line either, I'd have to see that put under a rated load to believe it. You need to talk to a pro in the business, they can tell you what you need to make it work. I'd forget about mile marker unless you are buying their system.

[Master Yota]

Your point about the size of the resevoir Charles is very valid. My only counter to that would be; How does Mile Marker do it with their winches? The typical GM saginaw power steering pump has a resevoir that holds mere ounces, and they tout that their system will pull all day long with no overheating issues. I feel that your idea to speak with a professional is the best plan so far. As for the size of my current resevoir, thats what was recommended for the pump.

I suspect that the amount of heat generated by the pump/motor will be directly related to the amount of work it needs to do. Simply winding in 150' feet of cable with no load shouldn't generate enough BTU's to cook anything. The wonderful thing about hydraulics is that it should, in theory, stall out if the load is too heavy, thus averting a thermal meltdown.

At least in a perfect world...

So resevoir size aside, Charles would you happen to have any info on the PTO specs?

I'm not saying the size of your reservoir is wrong for a steering system, in fact it is very typical in that application.

How does mile marker do it, you'll have to ask them that one. I've just shared a little of my hydraulic experience with you, that has been small fluid capacity and heavy load equals heat. Winding in 150' of cable with no load is one thing, you certainly can't base a system on a no load capacity and expect it to perform wnen you need it too. Neither do you want to design a system that will stall before it gets the job done, at stall and just before is when heat rises quicker than any other time. Ideally you want to design your system to pull the rated capacity of the winch without stall, otherwise you won't have much when you get done.

Another issue that doesn't wash with me is the fact you say mile marker says their system will pull all day without over heating. I never saw any Mile Marker product that impressed me, and I just don't believe that line either, I'd have to see that put under a rated load to believe it. You need to talk to a pro in the business, they can tell you what you need to make it work. I'd forget about mile marker unless you are buying their system.

Thank you Charles for your input. Hydraulics aside, can you answer some questions about the pto and winch?

What is the ideal shaft RPM to power the LU4?
What is the real-world rating of the winch's pulling capacity?
What is the stock PTO rated at? (I've heard 30hp, but confirmation would be nice)
Is the available torque output on the PTO shaft the same as peak engine torque ie. 180ft-lbs?

With these answers I could consult a hydraulic professional to determine the needs of the pump and motor and design a smooth running system. Any help is appreciated.

[MSeriesRebuild]

I don't recall all these specifics, I have the info somewhere, but just don't have time today to dig it up. Maybe someone else has a spec sheet handy.

[Juan]

I remember a Petersen 4 wheel and off road old article (like 10 years ago) about a winch shootout in the desert. They've tested the Milemarker against a warn electric winch. The test mule was a Dodge Ramcharger.

They've ruined three PS pumps during the testing, due to overheating problems mainly. According to them, the first one was in unknown shape since it was already installed in the truck and well used. But the other two were new ones.

Don't know if this helps, but maybe Milemarker don't have it all figured out.

I would personally use a Tommy gate lift electrical pump for driving the hydraulic motor with a big reservoir and a maybe a cooler.
You may even find one cheap in a junkyard.

[Master Yota]

Thanks for jogging my memory Juan, I actually remember reading that article! I've somewhat come to the decision to use a secondary pto driven pump to run the winch. After speaking with a pro last week, we determined that the primary source of heat with the powersteering pump setup, is from the pump itself. The pumps usually run at or near peak pressure all the time. With no load on the system (steering input) most of the time, the pump is straining against the relief valve, this is the primary source of heat in the system. Given the low flow rate (GPM) of the stock pumps, they don't get sufficient cooling (via the oil) to keep the pump from overheating.

While my pump (@4.5gpm) is almost 3x better, I'm still leery about cooking the pump 40 miles from nowwhere. Even if I do manage to get out of whatever hole I'm stuck in, I still have to drive x miles with 44" rubber and no power steering. Dosen't sound like any fun to me...

I've found some formula's recently which help make a better choice for determing pump and motor size. I'll post up my decision when the math is done...
In the meantime, I'm still looking for the stock PTO specs for comparison...

[Joe]

Thank you Charles for your input. Hydraulics aside, can you answer some questions about the pto and winch?

What is the ideal shaft RPM to power the LU4?
What is the real-world rating of the winch's pulling capacity?
What is the stock PTO rated at? (I've heard 30hp, but confirmation would be nice)
Is the available torque output on the PTO shaft the same as peak engine torque ie. 180ft-lbs?

PTO torque available at the winch would depend on the rating of the shear pin and not on what the engine and gear boxes could create. The shear pin is designed to be the weak link in the system. Potentially all of the engine torque is available at the PTO drive shaft but I seriously doubt the PTO drive shaft or even the PTO gear box could handle the full engine torque. If you know the shear value of the shear pin that will give you the max torque and that times the the winch gear ratio divided by the drum radius will give you the winch pulling power (ignoring gear friction of course). The ideal RPM would probably be the RPM where the engine developes it's maximum torque which is very low for the T245. I've seen a torque/horsepower chart for the T245 in one of the manuals and IIRC the peak torque was from about 700 to 1100 RPM. However a lower or higher engine speed (and it's corrosponding lower torque) may still create excessive torque for the shear pin. PTO horsepower can be calculated from the torque and chosen RPM but it's not really a valid number for a winch since full torque is only generated under a stall condition.

What is the real-world rating of the winch's pulling capacity?

The manuals say 7500 pounds on the bare drum. That's probably about right considering that a M37 w/w weighs over 6000 pounds without a driver or cargo and it's rated cargo capacity is 1500 pounds! Note that adding more layers of cable to the drum increases it's radius and reduces the wench's pull. That's why for heavy pulling sessions you're supposed to unwind and use all the cable even if you don't need the length. Somewhere there's a chart posted for the winch for one of the other MVs and it shows the decreasing pulling power as additional layers of cable are added to the winch and the decreases are significant.

BTW does anyone know the part number and/or rating of the correct shear pin? The idiot that I bought my M-37 from installed a grade 8 bolt!

[Josh]

Ray, if you have your heart set on running a Hydraulic setup, there is a boneyard near me that has an old international snow plow truck with a BIG clutched hydraulic pump. Back when I was going to hydro drive the original winch, I was going to use it, but, found that my Braden was in pretty rough shape. I have no idea what they want for it, but if you're interested I can ask and take pics for you, andif you want it pull it off. It is a nice deal because it is clutched, like an AC pump so it would only run when you wanted the winch, and it is one big mother F%^!ER!!! Line in must be 1 1/2", and line out has to be 1" It is hooked up to a big hydro system that ran the salt spreader, blade underneath, and the front blade. Ran by dual V belts.

[cuz]

The pin is ORD# 7373760, Chrys # 1189423, It is brass and drilled for cotter pin. 0.3075" diameter by 2 3/32" long from under head to Centerline of cotter pin hole.The ORD 9 offers no rating for the pin. The 8030 and 8031-2 offer no ratings for the pin.

[Master Yota]

Thanks for the reply's guys -

Joe, thanks for the extra math, I'll see if I can work it out to get a better idea of what the winch is capable of.
Josh - Thanks for the heads up on the pump - I'll consider it, but is sounds like it might be overkill (which is never a bad thing!)
Wes - Thanks for the specs on the shear pin, I'll see if can find some specs on a similar sized modern pin, and see if they'll work together...