Warn M8000 Winch Breakdown - Four Wheeler Magazine

We'd used our venerable Warn M8000 for about six years or so, and it had never let us down. We had rescued stuck trucks, righted rolled-over rigs, and extracted ourselves from rocky notches and waterfalls too steep to climb. Though our winch hadn't seen a lot of mud, it had been submerged underwater a number of times in creek and wash crossings. It had also seen years of fine desert dust that had surely worked its way into our trusty companion.

But in recent years, we'd noticed a little more noise coming from the drum assembly, so we decided it best to do a little inspection and maintenance as needed. You can find an exploded parts diagram in your original Warn manual, along with a parts list. If not, you can find them on Warn's Web site, in the "Replacement Parts" section. Once you identify any seals, gaskets, or other worn parts you want to replace, they can be ordered from your local Warn dealer for quite reasonable prices. Along with that, you'll want fresh grease for the internals.

We tore down our M8000, then cleaned, inspected, lubed, and reassembled it in a few hours. The job required only common handtools and was fairly straightforward. Many Warn models should be similar in this process. Follow along as we revitalize our winch.

1. To start the disassembly, we removed the detent screw that secures the clutch engagement lever and removed the lever, metal retainer, and O-ring seal.
1. To start the disassembly, we removed the detent screw that secures the clutch engagemen
2. Next, the 10 socket-head cap screws were removed from the end housing, freeing it and the ring gear that houses several planetary gearsets.
2. Next, the 10 socket-head cap screws were removed from the end housing, freeing it and t
3. With the end housing and ring gear separated from the drum support, you can see the hex shaft that transfers drive from the motor on the opposite end of the winch to the small 12-tooth sun gear in the end housing.
3. With the end housing and ring gear separated from the drum support, you can see the hex

4. Next we removed the splined drive gear from the end of the drum assembly. The two socket-head cap screws were removed and the drum support was separated from the two tie-rods.
4. Next we removed the splined drive gear from the end of the drum assembly. The two socke
5. With the end of the drum assembly exposed, we found the first drum bushing. These appear to be made from a nylon-type material and are used to support and locate the drum in the side plates.
5. With the end of the drum assembly exposed, we found the first drum bushing. These appea
6. Here you can see the drum support on the motor end (left) and the drum assembly. Inside the drum is a brake assembly that mates to the coupler on the motor shaft. Do not remove the brake or apply any lubrication to the brake.
6. Here you can see the drum support on the motor end (left) and the drum assembly. Inside

7. Next, we removed the second drum bushing from the motor-side drum support. Here is where we found a good bit of accumulated dust and aged grease.
7. Next, we removed the second drum bushing from the motor-side drum support. Here is wher
8. The last part removed was the motor coupler. We checked this piece for any signs of cracking or damage and made sure the spline fit was still snug to the splined motor shaft.
8. The last part removed was the motor coupler. We checked this piece for any signs of cra
9. Grasping the end of the motor shaft, we wiggled it to check for any play or looseness in the bearing. We found none, so we stopped disassembly at this point.
9. Grasping the end of the motor shaft, we wiggled it to check for any play or looseness i

10. Inside the end housing is a bronze bushing which supports the small sun gear. We checked for excessive play between the two and found they still fit close. On some Warn winches, this bushing can be replaced in the housing.
10. Inside the end housing is a bronze bushing which supports the small sun gear. We check
11. Massive gear reduction is obtained through the use of three planetary gearsets that reside in the end housing. We cleaned ours in solvent and checked for loose or damaged gear pins and worn teeth.
11. Massive gear reduction is obtained through the use of three planetary gearsets that re
12. The end housing has the sliding ring gear that is actuated by the clutch lever. This gear moves to engage the drum for powered use or to disengage and allow it to spool free.
12. The end housing has the sliding ring gear that is actuated by the clutch lever. This g

13. A hex shaft is used to transfer power from the motor drive to the sun gear in the end housing. We checked for any excessive looseness between the shaft and the inner hex inside the gear.
13. A hex shaft is used to transfer power from the motor drive to the sun gear in the end
14. For gear lubrication, Warn recommends using either Molylube 1 or Aeroshell 17 (or its replacement, Aeroshell 33SM) grease. We used Aeroshell 17, an extreme-pressure synthetic grease with wide temperature use range designed to prevent surface corrosion or seizure. It is available from aviation suppliers. We found it online at Pike Oil Company.
14. For gear lubrication, Warn recommends using either Molylube 1 or Aeroshell 17 (or its
15. With all our parts cleaned and inspected for wear or damage, we were ready to begin reassembly. We applied a dab of grease to the end-housing bushing and a light coating of 20-weight oil on the inside of the end housing and outside of the sliding ring gear before reinstalling it in the housing. The beveled spline ends on the sliding gear should be towards the back of the end housing.
15. With all our parts cleaned and inspected for wear or damage, we were ready to begin re

16. The first new drum bushing was lightly greased and pressed into the motor-side drum support. We applied a little grease to the motor shaft splines and slid the motor coupler back in place.
16. The first new drum bushing was lightly greased and pressed into the motor-side drum su
17. The drum assembly was installed and the second drum bushing installed in the other drum support plate. Each bushing has a small alignment slot.
17. The drum assembly was installed and the second drum bushing installed in the other dru
18. We closed up the drum area and secured the drum support to the tie-rods with the two socket-head cap screws. Check that the drum spins smoothly at this point.
18. We closed up the drum area and secured the drum support to the tie-rods with the two s

19. A little grease was applied to the splined drive gear, and it was inserted in the end of the drum. The hex shaft was replaced in the drum as well, fitting it into the hex end of the brake assembly.
19. A little grease was applied to the splined drive gear, and it was inserted in the end
20. Then the small sun gear was lubed and slipped into the bushing in the end housing.
21. The two smaller planetary gearsets were placed into the gear housing. Warn recommends that these assemblies be liberally greased but that the end housing not be packed fully with grease. On top of these goes the thrust washer (step-side up in this photo).
21. The two smaller planetary gearsets were placed into the gear housing. Warn recommends

22. The largest planetary set fits on top of the thrust washer, followed by the large ring gear whose splines mate to the raised area on the face of the end housing.
22. The largest planetary set fits on top of the thrust washer, followed by the large ring
23. The assembled end housing is reinstalled on the drum support and secured with the 10 screws. It's necessary to again align the ring-gear splines and the bolt holes for this attachment. The holes align every other screw hole, or every 72 degrees. Finally, the clutch lever and its seal and retainer are reassembled back onto the housing. The lower end of the lever is aligned in the sliding ring gear to operate the Free/Engage modes.
23. The assembled end housing is reinstalled on the drum support and secured with the 10 s
24. With the winch back together, we renewed the winch rope and installed a new abrasion guard from the guys at Rockstomper. Our winch was quieter again and ready to tackle whatever the trail would throw at us.
24. With the winch back together, we renewed the winch rope and installed a new abrasion g