Blackjacks 8.7AK

Blackjack

Evil Winch Doctor
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Joined
Dec 16, 2018
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3,891
Location
Kenai
Since my original thread I started on AK4x4 is gone and Pirate is gone wonky I thought I would post this here. I also have some changes that I will be making this summer that I will be adding.

So after years of stellar service out of my basket case 8274, I decided that I wanted to try something different. I have taken apart that winch I dont know how many times trying to tweak every last bit of no load speed out of it. And fast it is, so fast in fact that the guy I sold it too asked if I could possibly slow it down a little. But as much speed as I gained on the top end, I only gained a small amount at full pull.

So my goals of this build are to strike a better balance between no load and full pull line speeds, increase overall pulling power and duty cycle, and improve its ability to take on the Alaska climate. This will not be a twin motor competition winch, but rather a hardcore sleeper that can be built with mostly off the shelf parts.

This build will be happening in several phases as time and materials permit.

So we begin with a new 8274 PN 38631.

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Phase one is re-power and re-lube. The current 8274 uses the Bosch series wound motor PN 39972. A lot of people call this the 8274-50 motor, but this is not necessarily true. The 8274-50 (which marked the 50th anniversary of Warn) came out several months before the new motor did. This motor, once dubbed BIC (Best in Class) was put into production when they introduced the HS series winches. It is a very good motor, but not without its weaknesses. It is prone to corroding between the brush plate and the motor case, as well as the brush end ball bearing.

So the motor I chose for the 8.7AK is not the 9.5xp motor PN 68608, but rather its brother PN 70865. This is a series-parallel wound motor like the 68608, but is used in Warns industrial line.


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So the new motor should add a little over 500 lbs of pull, a solid two feet a minute increase in full pull line speed and much more run time due to its heavier windings (this motor is five pounds heavier than the 39972 but only two pounds heavier than the original prestolite used in the 70's). So to back this up I also replaced the solenoids with PN 68379. These are the solenoids from the power in side of the 9.5xp. The beauty of this is that they fit under the 8274-50 control pack cover with no mods needed. You can see in the pic the difference between the 68379 and the stock 72631



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So the items I am using for the re-lube are Roadranger SAE 50 Full Synthetic Transmission lube and Chevron Ultiplex Synthetic EP grease.

The 50 weight synthetic was developed specifically as the factory fill for Roadranger transmissions. With a cold pour point below -40F and recommended change interval of 500,000 miles in a Roadranger transmission, I feel this is the best choice for lubrication for the 8.7AKs gear box.

The Ultiplex Synthetic EP is a highly water resistant grease that works well at very low temperatures. The only two places that need grease are the dead end drum bushing and the brake pawl.

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So with the new oil in (I put a little bit more that the six ounces that Warn recommends, but do know that some can run out until the oil level is below the drum seal) but before I bolted the motor on, I mounted the winch to my Jeep. The reason I did this is that with the motor off of the winch, I can easily grab the drum and see if I have the winch bolted up squarely. A lot of people complain about how bad their 8274 free spools as well as some complain that it draws a lot of amps under no load. This is typically due to two things, a poorly built winch plate, or a winch that is bolted to the plate in a bind. A few minutes of tweaking now will make all the difference later.

Once I had adjusted the winch to the mount, it was just a matter of bolting on the motor (hint: pull the clutch all the way into free spool and remove the clutch assembly before removing the old motor), and the control pack. I make sure to use a little NYK-77 corrosion guard on the motor posts before putting the boots on, and a little on the solenoid pack connections does not hurt either.

As you can see from the pics, other than a slight increase in gap between the control pack and the gear case, this thing looks just like any other 8274-50.

This completes phase one. Phase two will deal with increasing the motors water resistance better than it is now (which is better than what it was stock), and couple of tweaks to the gearbox and brake.

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The 70865 has a thermal cutoff switch. Did you bother wiring it in? Have you ever had one of these overheat?
I did not. You can if you want to but I have never got the motor warm enough to worry about.
 
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Finally got some spare time so it is time to get the winch into the 21st century.

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I hadn't seen this before so when you posted up the larger heavier duty solenoids, I was fairly confused. Alright, he knows a whole bunch more about this stuff than I do, why didn't he use the contactor? What am I missing? And then, there it is.
 
I hadn't seen this before so when you posted up the larger heavier duty solenoids, I was fairly confused. Alright, he knows a whole bunch more about this stuff than I do, why didn't he use the contactor? What am I missing? And then, there it is.
Yeah when I first put this together in 2007 Warn only used contactors on the industrial winches and they were too expensive. I know I could have sourced one from Albright but my goal was to try and use all Warn parts.
 
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Fun part about living up here and worse now because of the coof is the lack of parts. Need three crimp lugs to make up new wires but none to be had in town for a few more days. Oh well got the control wiring adapted at least.

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I'm glad you posted this up here since I haven't done anything with my winch yet so I'll be following along. You have already given me some of the parts list I needed but getting to see it helps me a lot.

Thanks for sharing.
 
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Phase one is re-power and re-lube. The current 8274 uses the Bosch series wound motor PN 39972. A lot of people call this the 8274-50 motor, but this is not necessarily true. The 8274-50 (which marked the 50th anniversary of Warn) came out several months before the new motor did. This motor, once dubbed BIC (Best in Class) was put into production when they introduced the HS series winches. It is a very good motor, but not without its weaknesses. It is prone to corroding between the brush plate and the motor case, as well as the brush end ball bearing.

So the motor I chose for the 8.7AK is not the 9.5xp motor PN 68608, but rather its brother PN 70865. This is a series-parallel wound motor like the 68608, but is used in Warns industrial line.


View attachment 163488

What are the differences between this motor and the 9.5xp motor? I think I remember you saying the PN 70865 had a little more power?
 
What are the differences between this motor and the 9.5xp motor? I think I remember you saying the PN 70865 had a little more power?

They are very close to the same motor. Difference is in the brush clocking. The xp motor has a bit higher no load speed, and the 70685 has more bottom end grunt. In the grand scheme only winch nerds might notice the difference.
 
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Cable ends arrived so reworked the wires, added new terminal boots and applied corrosion preventative compound. If you do any wheeling in the wet or live where corrosion is an issue and want your wiring to last I cannot stress the importance of products like NYK77 or Ultra Seal. You can use dielectric grease but it is significantly more expensive so I save that for my spark plug wires.

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So in my searching of old Warn parts lists I came across something that was used on some export winches and that is a snorkle bolt. It allows you to completely seal the motor and run a breather hose into dryer quarters. After some digging I found that they had been discontinued but I was able to secure one by buying far too many of them. I thought about using a barb bulkhead into the airbox but I have something a little more old school to use instead. If this is something anyone is interested in let me know and maybe I can figure something out.

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So in my searching of old Warn parts lists I came across something that was used on some export winches and that is a snorkle bolt. It allows you to completely seal the motor and run a breather hose into dryer quarters. After some digging I found that they had been discontinued but I was able to secure one by buying far too many of them. I thought about using a barb bulkhead into the airbox but I have something a little more old school to use instead. If this is something anyone is interested in let me know and maybe I can figure something out.

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They always seem to discontinue stuff that some find really KEWL later on. And it's a shame many times because it might sell if they were to make it again.

Yes I'd be interested in one if you know of some place to get more. How do you seal the motor?

I might be getting ahead of you but is there any reason to drill the brake shaft as some have done? I know on the 70th Anniversary model that was done.