Just recently ive done a few repairs to the older drills tbh a new bare unit costs£140 but if you know what ur doing its a lot easier & cheeper- obviously the brushes are quick,cheep & easy to do but once u open the case everything is easily excessable & fairly cheep to replace.ive never heard of a clutch in the makita but could be wrong the main motor is called the armiture which has a magnet surrounding it & this slots into the back of a direct drive gearbox housing....the housing comes in 2 bits, the actual housing itself where all the gears are & are held in place by a big nut, its the thread on this nut that wears down cos its aliminium & so everything goes loose & wobbly.-the anvil(or drive u fix the socket onto) is located within the opposite end of the gear housing & to change this you just take the big nut off clockwise & the gear block falls out in one lump giving access to change the anvil.when putting it back together special note should be the luggs on the gear housing & the recess on the armiture magnet which need to sit in there respective keeps ....otherwise no mater how much u try u just wont get the 2 halves of the gun back 2gether.ope this info helps & saves you time & money sending it off