Pikuoff Posted August 1, 2024 Author Report Share Posted August 1, 2024 Rear diff is toast. The shop said all the sound was in from diff and coupler that's all one unit. It had lots of metal in the fluid. I tried to get most out with my pump but I guess that's why not much came out b/c my tube was pretty thin. About a $3k replacement. Probably not too surprising since it was never serviced for 170k miles. Now I know... Quote Link to comment Share on other sites More sharing options...
1004ron Posted August 1, 2024 Report Share Posted August 1, 2024 14 minutes ago, Pikuoff said: Rear diff is toast. The shop said all the sound was in from diff and coupler that's all one unit. It had lots of metal in the fluid. I tried to get most out with my pump but I guess that's why not much came out b/c my tube was pretty thin. About a $3k replacement. Probably not too surprising since it was never serviced for 170k miles. Now I know... Sorry to hear that you have a large repair bill. My thoughts are that the RDU shouldn't suffer without maintenance at 170K miles. Quote Link to comment Share on other sites More sharing options...
Cerberus Posted August 1, 2024 Report Share Posted August 1, 2024 4 hours ago, Pikuoff said: Rear diff is toast. The shop said all the sound was in from diff and coupler that's all one unit. It had lots of metal in the fluid. I tried to get most out with my pump but I guess that's why not much came out b/c my tube was pretty thin. About a $3k replacement. Probably not too surprising since it was never serviced for 170k miles. Now I know... Oof. 3k sounds high.. but maybe that's just me Quote Link to comment Share on other sites More sharing options...
Pikuoff Posted August 21, 2024 Author Report Share Posted August 21, 2024 Rear diff replaced and the car sounds/feels new again. Will be sure to regularly replace the fluid from here on out! Unplugging the rear diff connector definitely helped while I was waiting to get it replaced for anyone in the same boat. 2 Quote Link to comment Share on other sites More sharing options...
GoshenTop Posted yesterday at 04:41 PM Report Share Posted yesterday at 04:41 PM Thanks to all who contributed to this thread. I started getting the whine noise a few weeks ago. I stumbled into the PTU issue, and replaced the fluid in that. Still, the sound remained, but would stop when I would get to around 40 mph. I NEVER thought of looking at the Intelligent AWD display to troubleshoot. As Pikuoff reported, I could track the sound to whenever power was sent to the rear wheels. The fluid change of the rear diff didn't help. Next step is to inspect the driveshaft center support bearing. Until I get my GoPro set up to film under the car, I had a follow-up question. Does the driveshaft always turn, or it is controlled by the PTU? And if so, is it safe to assume that the rear diff isn't engaged until it receives a signal to engage? (If it always spins, then if the center support bearing was bad, it would reason that the noise would always be present.) Thanks! Quote Link to comment Share on other sites More sharing options...
1004ron Posted yesterday at 05:44 PM Report Share Posted yesterday at 05:44 PM 1 hour ago, GoshenTop said: Does the driveshaft always turn, or it is controlled by the PTU? Welcome. That would depend on your Model/Year. Please add your Model/Year to your profile signature - Settings - Ford Edge Forum Quote Link to comment Share on other sites More sharing options...
Cerberus Posted 20 hours ago Report Share Posted 20 hours ago (edited) 21 hours ago, GoshenTop said: Thanks to all who contributed to this thread. I started getting the whine noise a few weeks ago. I stumbled into the PTU issue, and replaced the fluid in that. Still, the sound remained, but would stop when I would get to around 40 mph. I NEVER thought of looking at the Intelligent AWD display to troubleshoot. As Pikuoff reported, I could track the sound to whenever power was sent to the rear wheels. The fluid change of the rear diff didn't help. Next step is to inspect the driveshaft center support bearing. Until I get my GoPro set up to film under the car, I had a follow-up question. Does the driveshaft always turn, or it is controlled by the PTU? And if so, is it safe to assume that the rear diff isn't engaged until it receives a signal to engage? (If it always spins, then if the center support bearing was bad, it would reason that the noise would always be present.) Thanks! Disregard! Edited 5 hours ago by Cerberus I was wrong 1 Quote Link to comment Share on other sites More sharing options...
dabangsta Posted 15 hours ago Report Share Posted 15 hours ago 4 hours ago, Cerberus said: 99% sure the driveshaft always turns regardless of year, but is only under load/ driven when the clutch is pulled in, in the RDU (diff plus clutch assy on the input side) In other words, the driveshaft spins but the power is not delivered to the diff until the clutch ramps in. As mentioned, it depends on the year. 2019+ has a disconnect in the PTU. 1 Quote Link to comment Share on other sites More sharing options...
Cerberus Posted 11 hours ago Report Share Posted 11 hours ago (edited) 10 hours ago, dabangsta said: As mentioned, it depends on the year. 2019+ has a disconnect in the PTU. Disregard! Yes but even if the PTU disconnect is disconnected, the rear wheels are still rolling down the road, and driving the driveshaft. Unless there is a disconnect at both ends of the driveshaft? I didn't think they did that.. Edited 5 hours ago by Cerberus I was wrong 1 Quote Link to comment Share on other sites More sharing options...
kruzr1 Posted 8 hours ago Report Share Posted 8 hours ago 2019+ has a disconnect RDU, which uses a different fluid. Quote Link to comment Share on other sites More sharing options...
Cerberus Posted 7 hours ago Report Share Posted 7 hours ago 45 minutes ago, kruzr1 said: 2019+ has a disconnect RDU, which uses a different fluid. I know my 2016 sport had a clutched RDU. But no disconnect in the PTU in my year Quote Link to comment Share on other sites More sharing options...
omar302 Posted 6 hours ago Report Share Posted 6 hours ago All model years have RDU with clutches. So when the clutches are disengaged it effectively "disconnects" the rear differential from the driveshaft. Pre 2019, the driveshaft will still turn because it is connected to the PTU/Transmission/Engine, while the rear differential will turn based on the speeds of the rear wheels. 2019+ models, the driveshaft stops rotating when the PTU disconnects. As can be seen in this video: 1 Quote Link to comment Share on other sites More sharing options...
Cerberus Posted 5 hours ago Report Share Posted 5 hours ago (edited) 54 minutes ago, omar302 said: All model years have RDU with clutches. So when the clutches are disengaged it effectively "disconnects" the rear differential from the driveshaft. Pre 2019, the driveshaft will still turn because it is connected to the PTU/Transmission/Engine, while the rear differential will turn based on the speeds of the rear wheels. 2019+ models, the driveshaft stops rotating when the PTU disconnects. As can be seen in this video: i don't have the patience to watch that video. one second in, and i'm out. I'll just trust you, apparently i'm wrong mark the date .. lol Edited 5 hours ago by Cerberus 1 Quote Link to comment Share on other sites More sharing options...
1004ron Posted 2 hours ago Report Share Posted 2 hours ago @GoshenTop as can be seen, it's valuable to have your Model/Year in your profile signature - Settings - Ford Edge Forum @Cerberus no need to beat yourself up over this - I only learnt about this AWD setup on the later models just the other day. MACT's videos are actually quite good, just need to fast forward past the intro which can be a little drawn-out on some of his videos. 1 Quote Link to comment Share on other sites More sharing options...
omar302 Posted 57 minutes ago Report Share Posted 57 minutes ago 4 hours ago, Cerberus said: i don't have the patience to watch that video. one second in, and i'm out. I'll just trust you, apparently i'm wrong mark the date .. lol I understand you. You can see the disconnection in action between the 2:15 and 2:25 marks. 1 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.