First off I always use this grease in the gearbox…………… the winch is 5 years old and I packed it with this from new ………. Its only been stripped twice in the 5 years…….
Here is the end of the drum and a close up of the roller bearing that the main shaft runs in. That is not rust you see…………… its some sh!t from the drum centre as I have just sprayed the bearing with a seriously strong degreaser to clean it out……….
Once cleaned, the bearing and gear shafts are liberally greased…………
Next the roller bearings in the 3 low range gears are cleaned ……….. the old grease turns a to grey brown liquid as the degreaser gets to work on it………
The 3 gears are repacked and mounted ……………….
Then the thrust washers are added and each gear is retained with its circlip.
This is followed by the high gear bias springs………….
The high gear is a plate, 7mm thick and extremely f’kin hard………… its made of the same stuff as the drum end plate and refuses to be centre punched or drilled……. Even with a colbalt drill bit. The plate must be mounted with the chamfer toward the main shaft………. This is so it will engage quickly and cleanly……
The plate is mounted and secured with 3 more circlips.
It has been reported that you should not really winch in high gear (a statement with which I wholeheartedly agree). Note that in high gear the thickness of the gear is only about 6mm, however, I guess the main shaft gear will shear before the plate ring gear. The high gear pull in lbs can be calculated as (motor torque (inlb) / drum radius (in))
In my application this is 3471/ 1.25 = 2776lbs or 1.2T, however, with a line speed of 45+ft/min in low I never use high gear…………
Next its time to give the whole gear assembly a good protective coat of grease. The more grease we get in the gearbox means there is less room for water…………
Now its time to assemble the gearbox casing……………this is the low gear locking pin. When you are dangling on the end of the rope this pin is holding the full weight ………. From this point on we will refer to it as the ‘Jesus’ pin. To engage low gear in dropping into any one of 4 holes in the periphery of the ring gear, thus the drum can only do 90 degrees before low is engaged. The pin engages by about a ¼ inch………
Grease the pin, fit the spring and insert from the inner of the casing. Then attached the low/free lever with its roll pin. It should be noted that the hole contains a small O ring to seal the pin shaft.
Then we move onto the high gear thrust bearing. This pushes against the spring loaded high gear plate to engage it with the main shaft. Again this is greased, spring fitted and inserted from the inner end of the case. The high / free lever is attached with its roll pin.
Both levers need to be operated a few times to made sure that there is no hydraulic action from the grease as the clearances are reasonably tight.
This is the ring gear thrust washer ……….. it is made from PTFE………….grease both sides and fit into the recess in the casing.
Here is the ring gear. This is the thrust side that goes face down onto the PTFE thrust washer. Again liberally grease and carefully slide it into the casing. Be careful not to get too much grease into the ‘Jesus’ pin locking holes, otherwise the grease will hydraulic and prevent it from locking……..spin the ring gear by hand to make sure that it will lock at each 90 degrees.
Then we fit the PTFE (NOT plastic) drum guide split bearing………….
Then the drum O ring seal goes carefully into the housing.
Now the tricky bit…………. Set the high / free to free and set the low / free to low………….carefully slide the housing onto the drum with a sloe turning motion. After a little fiddling and turning all 3 gears will line up with the ring gear and the housing will slide home
Stand the winch on end and fit prepare the mainshaft.
Ensure that the mainshaft thrust washer is fitted.
Grease the whole shaft and slide it into the drum centre to engage with the gear set.
This is the motor end drum split bearing………again PTFE.
Grease the end housing and fit the bearing with the thrust side toward the drum. Then fit the drum O ring seal into the housing……………
The end casing is fitted by a slight turning motion in order not to damage the O ring seal.
Fit the SS tie bars ……………..these are custom and the housing lugs have been helicoiled to 3/8 UNC……
Next the motor is cleaned for fitting………
Note that this also has an O ring seal……………
Liberally grease the motor face and bolt it to the housing using 7/16 UNC bolts………
Now we have a completed winch that will fight on for another year or two………
This is the reason for the rebuild………..
This was caused by the end plate to drum weld parting due to bunching on the side of the drum. The early MM’s are well known for this failure due to very poor factory welding in that area……………later models are fine……….
The end……….
Ian
