View Full Version : D6D Cat winch

dave morgan
12-14-2006, 10:50 PM
We have a D6D LGP with a 56 Cat winch...Pulled two teeth from the last two gears on the left side of the unit...It is stated as a slow drive in the service manual...If any gears need replaced, 'order new parts and delete one shaft w/gear set...It has two jack shafts with gears now, will only have one jackshaft when its back together.

I counted the gears, and figured gear reduction from 1000 rpm at the PTO for sake of simplicity...at 1000 PTO the two jack shaft winch turns the drum at 11 rpm...slow...with the conversion the drum will turn at 25 rpm, more than twice as fast.

With a torque converter will the faster winch have a better-longer-more reliable in a hard pull service factor than the slower winch had?..Not much I can do about it keeping the Cat winch...We can still get Hyster reman winch for $9500.00...it is going to cost $3700.00 to repair ours-cheapest winch repair I have ever had.

But, we still have a 17A that we have had since 1976 that we have never been inside the winch on it...its a Hyster D7D direct shift where the D6 is a power shift with three oil lubed clutches or brakes if you want to get technical.

Does the Cat winch have a better service record after the changeover?
Is the Hyster winch W6E better-stronger than the Cat 56 37U?

Thanks for all responces.

we are using these machines in the oil field...pulling in equipment on mud boats is what is so very hard on the winches.

Old Magnet
12-14-2006, 11:31 PM
Seems like you would lose considerable pulling capacity if you change from the 11 to 25rpm drum speed.

You can research the Hyster winch specs at: www.alliedsystems.com/pubs/pubs.htm

I don't have source of info for the 56 Cat winch, to new for me:D :D

12-15-2006, 12:53 PM
Dave, I agree with OM, I think you will loose pounds pull. For some applications it might not bother too much. I have a D6D, 20X with a Hyster W6F winch with the logging high fairlead. So far no problems with it. It will be interesting to hear others on comparing the two brands.

dave morgan
12-15-2006, 02:08 PM
I already forgot, but the W6E is supposed to have the pump off the engine flywheel, the W6F is supposed to have internal pump with hyd accumulator to keep the controls happy until the PTO turns some more...I found a dealer for reman Hyster W6E for $9500, so if the Cat doesn't work out we will look into that...WE have a manual shift Hyster on a 17A that hasn't caused a minutes trouble in the 30 years we have owned it...But had a Hyster W8K on a 977L that Hulcher's had made up special and pulled some gear teeth on it while pulling out a 235 excavator...The 17A winch is geared fast, tractor has to be running wide open if winching hard or the engine will pull down and die, so we keep a block and pulley handy with it, dead man back to the oil field headache...I think the faster 56 winch will pull enough, I am just concerned about its staying power...we ran 1 1/4 inch premium lang lay on the W8K and 1 1/8 on the 56 and D7...Winch service is good money IF things don't go the wrong way.

So, do you think faster gearing would be easier on the gear case and gearing on a winch or harder than a slow speed?..Cat actually calls the gearing sets low speed and slow speed...one would be 11 rpm and the other 25 rpm...take your pick on which is slow speed and which is low speed...The torque convertor makes winching a different ball game.

Old Magnet
12-15-2006, 04:27 PM
Kinda depends on how you are going to use it. For the same pull the reactions to the winch case would be the same but the low speed, more gears, 11 rpm version would take less loading on the engine and gear train to achieve it.

12-15-2006, 09:47 PM
How is the torque converter figured into this? catskinner

dave morgan
12-15-2006, 11:39 PM
the winch is eased into forward with the engine at idle, then increase engine speed while [hopefully] the load starts coming your way...With a clutch as the older D7, the engine has to be running pretty much wide open if the load is heavy or the engine will die...Not so with TC...just keep increasing the engine speed evenly until the winch drum starts turning...it seems very exact and smooth going until a tooth begins to break off a gear, then that sickening sound comes into play.

It seems to me that Cat decided one countershaft was enough, and a higher drum speed gives the winch an easier life, less torque, for sure...may not pull some things it would before, might have to bring in the second Cat...One conclusion here though, we need to get it to where it quits shucking teeth off those gears.

It seems to me, best of memory, that the Carco winches on oil field Cats were not a slow speed winch, but a more medium to high speed.

best case scenario is for first gear foward on the Cat is same speed as reverse on the winch...That way the roughneck can hold the tail chain as the Cat moves forward, then when enough line is pulled off, the Cat simply backs up so the roughneck or swamper can make the hitch, not having to pull the line off the drum creating a bird nest and taking a lot of time off the life of the wire rope.

Old Magnet
12-16-2006, 10:16 AM
I'm not up on the latest developments in winches but the earlier powershift/torque converter units had a separate hydraulic clutch and pump to disconnect the winch from the continuous turning power shaft. Sounds like they can also achieve this with a pump and accumulator in the winch also.