stefan_trethan Posted June 25, 2017 Report Share Posted June 25, 2017 Hi everyone, So I just got this DHR243RTJ hammer (XRH01Z in the US I believe). Right out of the box it was quite loud in drill-only mode at full RPM, you know that classic whining gear noise you get when you force gears together too tightly without any play. Of course I started to investigate and found if I back off the four gearbox screws just slightly (half a turn) the noise is much reduced. I also noticed it is much easier to turn the machine over by hand with the screws backed off. To make sure I am not imagining this I measured the current draw from the battery (now you know I am not a mechanical engineer ;-)) and it was reduced to about 6 amps with the screws loose, compared to 10 amps with the screws tight (these are full RPM no load drill only numbers). I would send the drill back and get the Bosch, but I also bought two Makita garden tools at the same time (which are OK) and I need the batteries / charger. The drill does work - I drilled two holes in concrete and it did fine, but it can hardly be good that it is binding like that in the gearbox? What would you do? I could exchange the machine on warranty and get a different one - that might or might not have the same design flaw. I could return the hammer drill and buy a separate battery / charger combo, and get a Bosch hammer instead. Or I could just leave it be and ignore the problem, but the binding may cause premature wear and certainly has a negative impact on battery life. Last option is I could fix it - find where it binds and/or shim the gearbox. I really do not want to do that since I specifically went and bought the best tool I could find, no matter the cost, so I would _not_ have to work on it right out of the box. Let me know if you have that hammer, if you notice the same issue, and your suggestions what I should do. I was really expecting Makita to be at least comparable to Bosch, but this issue, and fit and finish in general, would have me put it well below Bosch (blue) in quality, which is really quite disappointing for the money. Thank you! Stefan Quote Link to comment Share on other sites More sharing options...
kornomaniac Posted June 25, 2017 Report Share Posted June 25, 2017 Gears failing prematurely on the dhr243 is not a thing. If you have a failure it usually the plastic selector switch that pops off. It's only held in by plastic tabs. If you put the selector switch not in the right position, or you're already switching modes while the tool is still running you'll wear those tabs out prematurely untill the switch pops off. Runtime will be affected tho. Quote Link to comment Share on other sites More sharing options...
stefan_trethan Posted June 27, 2017 Author Report Share Posted June 27, 2017 On 6/25/2017 at 2:52 PM, kornomaniac said: Gears failing prematurely on the dhr243 is not a thing. If you have a failure it usually the plastic selector switch that pops off. It's only held in by plastic tabs. If you put the selector switch not in the right position, or you're already switching modes while the tool is still running you'll wear those tabs out prematurely untill the switch pops off. Runtime will be affected tho. Thank you for the reply. I thought I would get notifications, but apparently not, so it took me a bit to check back. Meanwhile I disassembled the gearbox and put thin phenolic washers between the housing and backplate to resolve the problem. The selector is a bit tricky, it needs to be turned clockwise past the hammer only setting to get the plastic tabs to disengage and get it out. To operate the selector I found it best to run the machine (on slowest speed!) while turning the lever. This way the clutch meshes easily. The sticker on top of the machine seems to specifically instruct one to run the machine while switching modes as well. I don't care for the plastic housing, lock plate and how it acts against the selector lever, otherwise the gearbox was made better than I expected. It sucks that I had to modify a brand new machine, but I am just not putting 100 Watts of friction into a gearbox. It is much better now, doesn't get warm any more, the noise is normal, and it runs smooth even on the lowest speed where it was really choppy before. Quote Link to comment Share on other sites More sharing options...
kornomaniac Posted June 28, 2017 Report Share Posted June 28, 2017 The sticker on top actually tells you to turn the chuck a little bit if the gears don't mesh up be careful with running the tool while using the selector switch. That's what makes it pop out Quote Link to comment Share on other sites More sharing options...
stefan_trethan Posted July 1, 2017 Author Report Share Posted July 1, 2017 I'm not good at reading those silly drawings they put everywhere instead of words these days, but my sticker definitely shows a hand actuating the trigger when switching between modes. I suppose it makes sense since the chuck can not be turned by hand in locked mode, but the motor can always turn the gears. I 1 Quote Link to comment Share on other sites More sharing options...
stefan_trethan Posted July 1, 2017 Author Report Share Posted July 1, 2017 On second thought that sticker probably means the motor should be run after each mode change, instead of changing all the way from hammer only to drill and vice versa in one go. It doesn't necessarily mean to run the motor _while_ changing modes, just in between? I really wish they would use words like they used to. 1 Quote Link to comment Share on other sites More sharing options...
kornomaniac Posted July 3, 2017 Report Share Posted July 3, 2017 Agreed. Confusing sticker Quote Link to comment Share on other sites More sharing options...
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