Vortechtral Posted October 22, 2019 Report Share Posted October 22, 2019 So, is it best to remove the rear diff cover and get rid of all the gunk and possible sludgey goodness, or just drive a bit and use the drain plug? I think I saw a video that they have a drain plug, maybe I'm mistaken. Quote Link to comment Share on other sites More sharing options...
onyxbfly Posted October 22, 2019 Report Share Posted October 22, 2019 You are correct the RDU has a drain plug. Quote Link to comment Share on other sites More sharing options...
Vortechtral Posted October 23, 2019 Author Report Share Posted October 23, 2019 Then is it better to drain via the plug or take the rear cover off, and get a better clean out? It looks like (just a lot smaller!) a trucks RDU, and they all crack it wide open from the rear cover, drain, clean etc, replace and fill. I haven't been under yet to see if the cover can even come off with ease. Are all bolts easy to get at? Or better to drive some, get the fluid nice and warm for easier flow then just use the drain plug. Quote Link to comment Share on other sites More sharing options...
onyxbfly Posted October 23, 2019 Report Share Posted October 23, 2019 Ideally best practice would be to remove the RDU cover and thoroughly clean it, but I have never thought about doing that to my lady's edge. Even though these SUVs are labelled as AWD they are not full time AWD. Or rather AWD is not engaged all the time. Check your AWD indicator. IMO the RDU does not get nearly as much use compared to the PTU. But everyone's driving habits and environment are different. You may very well may engage the rear wheels more than avg etc. The next time shes up in the air I'll try to snap a pic or two for you. Unfortunately she's not due for service till some time after the new year. Quote Link to comment Share on other sites More sharing options...
Waldo Posted October 23, 2019 Report Share Posted October 23, 2019 I'm not sure when the Edge switched, but I think in 2013 it was using the dry clutch RDU. Which means the fluid back there is only used to lubricate the diff gears, and not the clutches. As such it wouldn't really see a lot of heat or load, though the gears do spin all the time, no matter if the AWD is engaged or not. There's not a lot of history of rear diff lubrication issues on these Ford systems, so I don't know why you would even bother to change the fluid unless you've hit 150K miles. 2 Quote Link to comment Share on other sites More sharing options...
onyxbfly Posted October 24, 2019 Report Share Posted October 24, 2019 17 hours ago, Waldo said: I'm not sure when the Edge switched, but I think in 2013 it was using the dry clutch RDU. Which means the fluid back there is only used to lubricate the diff gears, and not the clutches. As such it wouldn't really see a lot of heat or load, though the gears do spin all the time, no matter if the AWD is engaged or not. There's not a lot of history of rear diff lubrication issues on these Ford systems, so I don't know why you would even bother to change the fluid unless you've hit 150K miles. Thanks for the clarification on how the RDU system works. Quote Link to comment Share on other sites More sharing options...
14AWD3.5 Posted March 15, 2020 Report Share Posted March 15, 2020 I had Firestone change mine out (drain and fill) at 60 ish K, probably didnt need it but it’s done for life now. It cost about $100, I was having the PTU fluid done at the same time so figured why not. Quote Link to comment Share on other sites More sharing options...
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