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hydraulic PTO winch on an auto?


hairychris21
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Hi All, Just come across your lovely forum and have been very impressed by the breadth of knowledge and experience being shared; Keep it up! :D

Anyway, the reason for my post: It looks like i'm going to be bunging an ex utilities hydro PTO pump on the back of my transmission to power my previously oh so slow but steady milemarker... a) because I want to, and B) because I've upgraded to a serpentine belted V8 and now seems as good a time as any, and c) because i want to...

Thing is i run a 4 spd auto, and have no idea how this will work in practice. I'm wondering if I'm going to need a way of upping the revs for winching to stop slippage? (other than just my right foot that is, when i'm not sitting in it i mean.

I'm thinking that a plus point is that drive assisting will be possible, unlike with hydraulic winches on manual motors... any thoughts?

also, having read the 'building a fast hydro winch' thread in the techie archive (fantastic thread; muchos kudos) I'm beginning to realise that this may get a little complicated, I mean 'over centre valves', 'pressure release valves', 'spooling valves' ummm eh? where on earth am i going to find this sort of stuff at the right money? any ideas?

All help/advice would be greatfully appreciated, i'm scratching my head a little...

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Thing is i run a 4 spd auto, and have no idea how this will work in practice. I'm wondering if I'm going to need a way of upping the revs for winching to stop slippage? (other than just my right foot that is, when i'm not sitting in it i mean.

Not sure about the rest but there are some very good hydro men on here, but winching when no one is in vehicle to controll it tut tut.

BTW, welcome to the best Forum by far :)

Peter

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Welcome :)

Paul Wightman on here used to run a mechanical winch off a PTO on an auto IIRC, which is much the same set of problems as far as slippage in the torque converter is concerned.

I don't think drive assist works because the pump is effectively coupled to the wheels not to the engine, so when the TC is slipping it isn't driving the pump either...

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also, having read the 'building a fast hydro winch' thread in the techie archive (fantastic thread; muchos kudos) I'm beginning to realise that this may get a little complicated, I mean 'over centre valves', 'pressure release valves', 'spooling valves' ummm eh? where on earth am i going to find this sort of stuff at the right money? any ideas?

The local hydraulics shop would be a good place to start - some of it's not cheap but (at the risk of starting an argument) neither is modding an electric winch to get similar performance. My local place is Hyphose, there's also Pirtek. Although you're not familiar with all these strange sounding valves they are all run-of-the-mill stuff for the hydro guys and not nearly as exotic as they sound.

Hydro stuff turns up a fair bit on eBay if you are prepared to mix-n-match but obviously there can be problems in doing so.

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Ok

1st things 1st

Welcome :P

ok

Re your question, there is no prob or frankly much difference in fiting a Hrd PTO to a LT230 be it a LT77 R380 or Zf or 3 speed auto, they will all fit and all work.

They are mainly used with transfer box in neytral (no drive to wheels) and then selecting a gear, with an auto I suggest you choose and "Lock" the gear - prob 2nd, then all you need is 1500-2500 RPM (dependant on PTO Pump requirements) and away you go.

Drive assisting on one of these units is mainly next to impossible - its a bit like juggling soot, next to impossible but theoreticaaly possible :), and most who try do give up. There are posts on this forum about drive assist, pop these words in the forum search bar and have a read.

As to complexity it may sound as such but its not really, take it one step at a time, and feel free to ask Qs.

I run a hydraulic "Thing" on the front, and a MileMarker on the back, Dual spool block PTO Driven, transforms the MM more than you can ever belive !

Of Course, for a proper winch you need electric :lol:

Nige :ph34r:

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Drive assisting on one of these units is mainly next to impossible

Our 90 is an ex-utility with the SV factory-fitted H14W hydraulic installation.

Ours has an electrical interlock that kills the engine if the transfer box isn't in neutral when the PTO drive is engaged, but it's easy to disable this and it is theoretically possible to drive assist when winching.

But it just doesn't work cause you've got to be in 4th or 5th gear with the engine at 1500 to 2000rpm min (must be approx 2000 to 3000 rpm PTO speed) to get the hydraulics working and that's obviously not going to work cause trying to drive in low box in 4th or 5th gear when you're trying to winch out of the gloop, well, need I say more... :lol:

More than likely IMHO you're going to have same problem with an auto -- 2nd gear is unlikely to generate enough rpm at the PTO, and by the time you've got enough PTO rpm the wheels will be wanting to turn far too fast.

Could be made to work but would need a hydraulic pump that works at whatever RPM the PTO reaches at tickover in low 1st or 2nd on a manual gearbox :o I have absolutely no idea if such things exist :blink::o:blink::lol:

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Nice one guys, :D @ the immediate response!! and thanks for the welcome :blush: its appreciated!

I shall report back, and mabe pick some of your brains again soon, now I just need to get the motor install finished... (kind of a priority to have a truck that moves under its own steam i guess...)

winching when no one is in vehicle to controll it tut tut

I meant when the motor is used to recover someone else, or when I'm (trying) to respool the rope neatly. not everyones got a full time winch monkey! lol!

Anyone had much experience with the big 'soft start' remote solenoid valve offered by mssrs A Murray? Seems a good idea, but I've never used a fast hydro winch, and I quite like the sound of the controlabilty of a spool valve thingy. wouldn't adjusting the revs of the vehicles engine do the same thing though? :unsure:

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I used an auto pto setup a while back on hydraulic and its not what I was looking for, shifting the transferbox into neutral and selecting drive will get it spinning at a fair rate but without drive assist.

Running the pump in a crank driven format however makes it completely different, you can then balance wheel speed with winch speed with ease or divorce one from the other at will. the old farts like to use tractor levers but thats mostly because they are too fat fingered to operate a switch (hi Nige and Ian :lol: ) but the electric valve setup can be easily as precise as any manual spoolvalve (bodyshop vid HERE )

welcome to the nuthouse by the way :)

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Chris, this isn't really my thing but I remember reading that one of the posters on here and Devon 4x4, Lara, was running an auxillary pump along side a PTO pump which helped with drive assist. I can't remember exact details but it might be worth having a word with him.

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Ever so slightly off topic but I once had to winch a badly stuck Forward control 101 Landy out of a mud hole. The vehicle was fitted with an Auto trans and the military issue side/centre mounted mechanical pto winch that due to the torque convertor slip did not have sufficient pulling power for that recovery. The winch rope on my truck was not long enough to reach the 101 so we unspooled about 50 ft of rope from its winch and connected it to the end of my rope. As soon as my winch began pulling, the 101 winch began unspooling because it didn't have a brake or self locking worm gears and the auto's torque convertor did not provide a positive connection between the engine and the winch to prevent unspooling. We ended up bulldog clamping the 101 winch rope around the pintle hook to provide a positive attachment.

Bill.

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...badly stuck Forward control 101 Landy out of a mud hole. The vehicle was fitted with an Auto trans and the military issue side/centre mounted mechanical pto winch that due to the torque convertor slip did not have sufficient pulling power for that recovery.

Blimey, must have been a mud hole at the bottom of a mineshaft, lol! Seriously tho, I wonder if there was something wrong with the torque converter, or if the guy in the 101 didn't give it enough cojones? because the auto box should have been able to supply more than enough torque to winch in with a moderate amount of revs, given the low gearing of a pto mechanical winch. Also i'm pretty sure that the torque converter should lock uo completely at a certain point in the rev range, tho I'm no expert, hmmm...

Or is this an inherent problem with a pto powered winch on an auto box? I hope not, I'm kinda commited now... Any thoughts people?

HC

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Blimey, must have been a mud hole at the bottom of a mineshaft, lol! Seriously tho, I wonder if there was something wrong with the torque converter, or if the guy in the 101 didn't give it enough cojones? because the auto box should have been able to supply more than enough torque to winch in with a moderate amount of revs, given the low gearing of a pto mechanical winch. Also i'm pretty sure that the torque converter should lock uo completely at a certain point in the rev range, tho I'm no expert, hmmm...

Or is this an inherent problem with a pto powered winch on an auto box? I hope not, I'm kinda commited now... Any thoughts people?

HC

I am not suggesting that our experience will be repeated with other types of winches, but with auto trans you probably should be looking at a winch design such as a worm drive, that will hold the load even when power is not being applied, otherwise many winching tasks require that you remain in the driving compartment.

101 winches are not particularly low geared and with engine turned off it takes very little effort to pull the rope off the drum. The Turbo 400 trans only has a 1st gear ratio of around 2.6:1. In a tug of war of the 101 winch wth engine at around 3000 rpm verses the tractive effort of my 2 1/4 litre engined landy in low 1st (49:1) on a surfaced road , my vehicle was able to pull the rope off the 101's drum.

Bill.

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I am not suggesting that our experience will be repeated with other types of winches, but with auto trans you probably should be looking at a winch design such as a worm drive, that will hold the load even when power is not being applied, otherwise many winching tasks require that you remain in the driving compartment.

101 winches are not particularly low geared and with engine turned off it takes very little effort to pull the rope off the drum. The Turbo 400 trans only has a 1st gear ratio of around 2.6:1. In a tug of war of the 101 winch wth engine at around 3000 rpm verses the tractive effort of my 2 1/4 litre engined landy in low 1st (49:1) on a surfaced road , my vehicle was able to pull the rope off the 101's drum.

Bill.

That implies the torque converter was running backwards which implies there is a serious problem with it if the engine is doing 3000rpm? The stall speed of a TC should be less than that for a start... so if the output was running backwards it should have dragged the revs down so the "difference" was 2400rpm or whatever the stall speed was for that particular TC, I think?

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Not 100% but my thinking is this. If you floor the throttle on an auto the engine will go up to the "stall speed" of the torque converter which is usually somewhere in the range 2200-2700rpm and it won't go any higher. The engine is developing pretty much maximum torque in this range, if its a V8. So if the engine is running full blast one way and then you start turning the output shaft backwards (which I am sure you could do with enough torque! though bearing in mind the TC has a torque multiplication effect I expect you'd need quite a lot) then the effect must surely be to drag the revs down so the "relative" speeds of the two are the same as the stall speed? I'm just saying that if the engine can run at 3000rpm while the winch is being dragged out then it sounds like there is something wrong somewhere, especially when you bear in mind the gearing effect on a winch.

My thinking might be cocked up here but I can't immediately see why, anybody else got any thoughts?

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a fast PTO mounted hydraulic pump needs about 55lb/ft to run at max pres/capacity (according to the Hydro specalists who did my calcs for me!), can't really see how this would affect an auto- at low engine rpm the TC is multiplying the torque so a V8 could be expected to be putting around 200lb/ft at 1000rpm through the g/box.

TC slip is really irrelevant when we are talking about these numbers!

sounds like the gearbox was in neutral above to me.

an overcentre valve would stop this happening completely.

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I would buy the knackered torque convertor diagnosis if the same vehicle which is also fitted with a worked over 454 cu in big block didn't pull accelleration times comparable to and in many cases better than dedicated hot rodded road cars at the annual Summernats hoon fest in Canberra a couple of weeks after the winching episode. The transmission may have been in neutral on both occasions. I can't be %100 certain as I was in the other LandRover. The real point is that without a self locking geartrain in the winch head, or an effective brake as in the hydraulic line lock valve pugwash suggested,the rope would unspool when power source is disconnected if the vehicle is hanging on the rope when winching up a steep slope for example. The 101 winch is all mechanical drive with the exception of the torque convertor, so the only means of preventing overun without the power source connected would be to place the t/case in high or low and apply the service or parking brake. This would require that driver remain in vehicle, which depending on circumstances is not always practicable or desirable.

Bill.

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A question for the Hydro experts. Are gear type hydraulic pumps and motors,similar to those fitted to LandRovers own optional hydraulic winch, positive enough in their displacement that a line lock would act as an effective brake ?

Bill.

Not 100% sure, but I think so (i'm no hydro expert!)

To change the subject; Alan from Alfred Murray suggested that I change the winch motor for a smaller capacity one now that I'll be running PTO powered rather than power steering pump, in order to take advantage of the higher pressures... I don't understand, why would this be benificial??

HC

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Not 100% sure, but I think so (i'm no hydro expert!)

To change the subject; Alan from Alfred Murray suggested that I change the winch motor for a smaller capacity one now that I'll be running PTO powered rather than power steering pump, in order to take advantage of the higher pressures... I don't understand, why would this be benificial??

HC

Smaller motor would speed up the winch.

He has said this many a time, its a sort of fix, but one I have never got my brain around

There is a correlation between pressure and speed, but for simple terms forget this, and just concentrate on :

FLOW= SPEED

and

PRESSURE = PULLING POWER

So switching a winch motor to a smaller one does mean it will spin faster, but why not just up the PTO Pump itself and drive more fluid, then set the PRV at the right pressure for the winch ?

What he is saying I think is that as you can increase the pressure and have the same PTO driving, shoving the same amount of fliud around the system into a smaller winch motor means the pressures will jump, as will the sppeds as your driveing the motor faster etc

It makes some sort of sense, but just get the PTO / Motor on winch / and winch / pipework etc all matching in the 1st place !

If you are going PTO route get all main pipes in doyuble braided 1/2 bore BSP fitting (main feed to PTO Bigger) and use control blocks, you can get a bowden cable attsnhment, which then could be placed somewhere outside the 4x4 as a on / off / on lever should you wnat.

Best to work out what you have itn terms of 2Bits" nowm, and then work out what you options are

Nige

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Hi was wondering what oil you hydro guy's use ? I just changed mine from 26 to 46 viscocity ,upped the prv to180 from 150 which has improved the pull ... I think the 46 grade has made as much difference as upping the prv.

the winch is a pto converted to hydro

pto pump 8.5 gpm

motor 6.5 gpm reversible (with leak off)

25 litre tank

seems to pull well enuf ...would be interesting to get it on a load cell one day.

........as to your orig question you can winch and drive with auto if the wheels spin & pto is engaged you will get winch power but much slower and less pull than optimum pump speed. I think with crank driven (Jez) you need a chain drive to take the load of the pump . As HFH says flow = speed & press = pulling power. Will be interesting to see how you get on.

cheers :)

Steveb

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Hi Nige.

I've got: The PTO, Pump, Tank and oil cooler + lots of assorted hoses etc from an ex utility 130 that never had a winch, just plugs for tools. looking at the state of the oil when we drained the not inconsiderable tank, I doubt its done much work at all. I've got the hose from the tank into the PTO... you're right, its blimmin huge! I was thinking of mounting the (rather large) tank where my battery is at present (I haven't quite decided where to put the battery yet mind...) as it was originally mounted where my petrol tank is.

I've also purchased this from th'ebay... please tell me its what I want... :blink: Can you adjust the PRV? any idea how? or will it all become clear when i've got me mitts on it.

I cant decide whether to go vehicle based spool valve or remote control valve. any thoughts? I've seen this, would that be a fair price?

Lastly, do I need one overcentrer valve or two, and what sort of price would be reasonable for one?

Ta mate,

Chris

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Some basic hyd formulae for pumps and motors (note a constant may be required depending upon units desired):

Pump and motor flow = revs / time x displacement

L/min = [r/min x cm^3 / r] / 1000

Hydraulic power = flow x pressure

kW = L/min x bar / 600

Pump input power = hyd power / overall efficiency

Motor torque = pressure x displacement / 2 x pi (pi ~ 3.142)

Nm = [bar x cm^3 / r] / 20 x pi

A smaller displacement winch motor makes sense if the pressure is within reason. Also a geroller, rather than gerotor motor is better (higher rated pressure and more efficient).

We need a particular torque from the motor to create a particular line pull.

If the motor displacement is reduced, the 4th formula (above) tells us that we need to change the system pressure in the inverse proportion to the change in displacement. ie. halve the displacement, then double the pressure.

If the motor displacement is reduced, for the same flow from the pump, the 1st formula tells us that the motor speed will change inversely to the change in displacement. ie halve the motor displacement to double the speed.

Bill, the high torque, low speed motors commonly used for vehicle winches are gerotor or geroller style, not gear motors. But yes, some internal leakage can occur, but is not significant with motors in good condition.

Chris, you need either an overcentre valve, or a counterbalance valve. Only one is needed because the load is always in one direction (the direction of the rope tension on the winch drum - if you push the rope. it won't cause the winch drum to rotate).

If you want to lower a load (eg. power out with the vehicle lowering), you should use an overcentre valve. If you only want to winch up a slope, then a counterbalance valve will do.

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