DCF899

[eddie1976]

Anyone have a DCF899 high torque impact? The owners manual says 100 ftlbs tightening on setting 1. I was changing tires today and when I was tightening the nuts with it, it would start to hammer and it seemed like it was done tightening. I put my torque wrench on the nuts and saw that they were barely tight...I was able to do almost a full turn before reaching the desired torque (85 ftlbs). 

 

It is out of warranty (bought in 2016) and barely used. I used it to rotate two sets of tires every year since then. Very light duty stuff. Not sure if it ever worked differently or if it was like this since day 1. I'd kick myself if it was like this from factory and I never sent it back for repair. 

 

I'm able to keep the socket from turning holding it by hand while depressing the trigger on setting 1. I assume this is not normal?????

 

Anyone have any thoughts?

 

 

 

[Biggie]

This is probably normal.  I have a dcf899 at my shop I could give it a socket in hand test on monday but they usually are pretty weak in settings 1.  There are just so many variables that the impact has no real way of knowing what torque its hitting in setting 1.  All the settings are doing are changing the motor rpms.  Most manufactures won't even state a torque in these lower speed settings.  Dewalt for their testing probably took one specific size, new, and lubricated fastener and then hammered on it for 15-20 seconds at that rpm and got an average reading of 100ft lbs over 100 test.  Now you're probably tightening a different size lug that may or may not be corroded and after about five seconds of hammering you probably stopped because yes it probably has more or less stopped turning but you're actually not getting maximum torque in that amount of time.  This is pretty common with all brands of impacts as marketing numbers and real world numbers don't always match up.  

[eddie1976]

Thanks @Biggie. Let me know what your test shows Monday. Very curious. A couple of weeks ago I was helping a friend who has a Rigid unit. On setting one he said that one goes to 60 ft pounds. When he was putting on the lug nuts, it made them pretty tight and then he hit them with the manual torque wrench set at 80, and the nuts turned a mm or two and clicked the wrench. It was pretty convenient compared to my DCF899. On the second setting on the DCF899 Dewalt says 300 ft pounds. If it is anywhere near that I don't want to hammer on the lug nuts. 

 

Thanks again for the response and for checking. 

 

 

[Biggie]

Sorry I was busy the last couple days at work but I did finally check and mine in the 1st setting can be held from turning with my hand.  So I would assume yours is pretty normal and I know the first gen high torque from Milwaukee was said to do 100ft/lbs in setting 1 but it never really did similar to the dewalt.  An impact just isn't precise enough to accurately set a specific torque maybe the exception being the milwaukee high torque "one-key" models. 

[eddie1976]

1 hour ago, Biggie said:

Sorry I was busy the last couple days at work but I did finally check and mine in the 1st setting can be held from turning with my hand.  So I would assume yours is pretty normal and I know the first gen high torque from Milwaukee was said to do 100ft/lbs in setting 1 but it never really did similar to the dewalt.  An impact just isn't precise enough to accurately set a specific torque maybe the exception being the milwaukee high torque "one-key" models. 

 

Thanks. Appreciate you looking.