hello and thanks for visiting our website rebuilderinabox.com in this video we're going to learn how to rebuild the internal fan bosch alternator which is popular on the dodge ram that does not have a built-in regulator and also various german car applications and the gm 03 to o5 impala monte carlo grand m has an internal fan very similar to these made by bosch but it has a built-in regulator first thing that needs to be done is the plastic cover taken off the back remove the two 15 millimeter nuts and the phillips screw this one has a voltage regulator but a lot of them just have an empty brush holder assembly they all mount up the same though there's three phillips heads that hold the assembly on remove those next there's three screws that we just took out the two long ones actually hold the two places we're about to point to in the alternator the third shorter screw is only for the building regulator which you can see has the brushes already assembled in it you can see the four through bolts on the outer diameter of the alternator that hold it together they have phillips heads on but the best thing to use is a 5 16 socket after the bolts have been unthreaded from the front plate you won't be able to remove them and get them past the rectifier and we want to leave the rectifier all soldered in place so just leave them in there one of them will come out but the other three won't pass the rectifier now we have to take the front half out of the back half hold the back half with your left hand and tap on the front half with a ball pin hammer so the rear bearing is held in place with the rear aluminum plate with a plastic tolerance ring usually when they come apart the tolerance ring sticks to the bearing so you have to take two screwdrivers place them 180 degrees apart and pry up to get the tolerance ring off sometimes the tolerance ring i should say quite often the tolerance ring will break when you're removing it and so that's why we supply a new tolerance ring with all the kits occasionally on some alternators we'll be faced with a bearing that needs to be removed from the shaft the tool that makes this job the easiest and worthy investment for any shop is a dremel you'll be needing a reinforced cut off wheel the dremel and the reinforced cutoff wheel are available at any big box store lows home depot or even a walmart draw a line on the outside race of the bearing on one side and then 180 on the other side draw another line we're going to use the dremel wheel to cut along that line we've cut through the one side we're going to turn it to the other side and cut the other outside half of the race after the outer race and the balls in the cage have been removed we need to deal with the inner race basically following the same procedure one method if you can get a grinder in there or a grinding wheel you can grind a piece off the side so that it gets down to the shaft and it relieves the tension on the inner race we prefer to use our dremel for this in the same fashion i scribe the line and then describe another line on the other side 180 away from this one and use the dremel to cut it off after you get it most of the way cut through the actual race itself is so brittle you can take a chisel and just hit it quickly with a hammer and it'll shatter off if you have a little bit of collateral damage on the shaft itself or up into the rotor body it's of no significance as always eye protection is a must to remove the pulley wrap a rag around the outer diameter of the pulley then you need a half inch impact with a 15 16 socket counterclockwise if the pulley gets stuck on the shaft take two screwdrivers drive them underneath the pulley in between the front plate and the pulley and pry up on them screw the pulling nut back onto the shaft halfway down through the threats place the rotor and front plate assembly in a vise so that the rotor goes down through the open jaws of the vise but sits literally in a vise so that the rotor goes down through the open jaws of the vise but sits loosely place a rag on the vise beam so that the slip ring has protection as it comes loose spray some pb blaster on the shaft get a 2x4 or chunk of wood place it on the shaft and hammer on the top of the wood take note of the position of the pulley spacer that is left lying on top of the shaft the wide part of it goes out the narrow part with the skinny raised up part goes towards the bearing notice the four phillips head screws holding the bearing retainer in remove the four phillips head screws sometimes they don't come loose very well put a phillips screwdriver in there and tap it down with the hammer that helps break the taper loose and they usually come right out remove the front bearing by flipping the front plate upside down put a three-quarter socket on the bearing and tap it out putting the front bearing back in the front plate you can heat the front plate in an oven for 10 to 15 minutes at 350 degrees it'll make it a lot easier to install the new bearing when you go to put the bearing back in tap only on the outer race install the front bearing cover and the four retainer screws place the rotor in a vise and use a piece of sandpaper to clean up the copper slip rings clean up the steel shaft where the bearing goes with a piece of scotch brite place a drop of oil on the shaft and spread it around with your finger take a 17 or 18 millimeter deep well socket and place it over the slip ring to make sure that it doesn't interfere because we're going to use that as a tool to push the rear bearing on place a couple drops of oil on the drive-in shaft start the rotor shaft into the bearing then turn it upside down and tap on the outer plate the shaft should be coming out that much when the bearing is all the way in place install the pulley spacer next with the small portion towards the bearing we're using the 17 18 millimeter deep well socket placing the pulley back onto the shaft we need a half inch impact and 15 16 socket put the lock washer on get the nut started hold on to the outer diameter of the pulley with the rag looking down inside the rear plate notice the three notches for the installing of the plastic bearing tolerance ring you'll notice the three notches on the black plastic tolerance ring insert the black plastic tolerance ring so that the opening is facing where the brush holder or voltage regulator is going to mount set the front plate in a vise with the rotor facing up line up the paint marks on the sides and set the rear plate back onto the front plate use the 5 16 deep well and a quarter inch ratchet to tighten the bolts the rest of the way use the cross pattern so the bearing is inserted in the rear assembly evenly four places need to be cleaned very efficiently the two ground pedestals where the voltage regulator gets its grounds at clean those with a wire toothbrush also for the hot lead clean the aluminum around that surface area and if you have a built-in regulator you'll have a wire loop on the one side that has to be cleaned if you have an external regulator there's only three places that you need to be really careful with the places that were just cleaned we need to install a lay layer of white lithium grease or dielectric grease to keep off any future corrosion install the regulator by sliding it into place which simultaneously loads the brushes if you're working on a voltage regulator model install the last small screw for the stator activated loop flip the bag cover over and wire toothbrush the fitting that's closest to the battery post and install tiny layer of white lithium grease or dielectric release put the lid back on install the two 15 millimeter nuts put the phillips head ground screw back in and you're done you