Cerberus

No. I heard the whole conversation, this was just to evac and charge (& dye) the system, so they could find the problem and fix it, for an additional cost This time of year, I see AC service specials for under 100$ all the time, and yeah, we know that's not going to ne the whole bill because if it needs service at all, chances are there is a leak that should be fixed too, or a failed component. But charging 440$ right up front, that's a big nut with no rationale for it.

Afternoon update, after driving cross town to the local Costco for a fuel up and back (losing one mic wire en route.. got under a tire somehow, heard the wire pop) I finally got a sense of the buzz/hum/roar from the right rear wheel hub.. which is where I thought the problem was from the start. So, problem confirmation in place, I did absolutely nothing lol. It was warm today. I'll limp it to next weekend and do it then. If it lasts that long. I'll probably do a photo series of the job. Side note, I walked into a local shop to get a quote to run my veh up to speed on the lift, and heard the desk dude quote a poor unsuspecting woman $440 to evac and recharge an AC system. ... and I turned around and walked out. Quickly. I almost wanted to tell her to bite the pillow but I'm not trying to light fires that close to home.. but this kind of thing makes me think I should really open my own shop..

morning service update, First, the RDU rear cover is not only an integral part of the ring gear carrier bearing system, It is also a key part of the mounting of the RDU.. so I'm not messing with that, at least not in the vehicle. And if i remove it, I will very likely only do so with a new or low mileage used/reman unit on hand. It looks fairly accessible to swap out. Having just extracted the fluid and refilled the RDU, i can make a couple observations. The magnetic plug was furry again, but not hugely so, less so than prior removal, The fluid was a dark with a fine metallic suspension (arguably no biggie for a 90K driveline) , but no larger pieces, so it will probably be ok for a while. All seals on the unit are still dry. Puzzling but I'll just STFU and be happy for that! I did reposition the RDU mic onto the rear cover so maybe now i'll get a better sense of any problem there Time to drive

Yes, AWD. Interestingly, the right side output seal which had an old leak stain around it when I refilled the RDU last month, is not leaking. I washed it down with a brake clean solvent at that time, and when I was hooking up my mics yesterday I noticed there was no active leak. I plan to extract all the fluid I can today for forensic purposes and refill again. I am reluctant to open the rear cover since the carrier bearing caps are integral to the cover.. but I may end up doing that if the problem is not identified soon

Today I hooked up my 6 channel mechanical mic to the rear wheel hubs, left and right, and the RDU in hopes of tracking down the source of the noise that I thought was a wheel bearing. Plot twist, it does not seem to be any of those parts making the noise. I can hear the pads hiss on the rotors when I am braking, and I can hear a near constant hiss from the RDU, but nothing that coincides with the wheelspeed correlated pulsating roar, that I thought was a wheel bearing. I'm at a loss.

Yeah, at that usage, it will take forever for them to wear out

New tires; Continental Extreme Contact DWS 06 Plus XL (x4) delivered from Tire Rack. So I ended up going with OEM size (265/40R21) for cost and because the local tire chain (Discount Tire) absolutely refused when I asked if they would mount 295 width tires to a 9 inch wide wheel.. (pricks) I mounted up my winter wheels so I had my summer wheels loose and brought two of them in to work & swapped them on lunch one day, easy peasy I could not do the other pair (did not have time & freedom to do it) so I took them to Discount Tire to swap off the old and mount the new. They charged me $93 and change for mounting and balancing on two loose wheels.. dirty bastards. One star. Do not recommend. Will never go back. I LOVE the tires though. Highly recommended.

definitely sounds like a bad shock.. but I agree that the likelihood of a bad shock out of the box is fairly low. did you compress the shock and release it before install? There used to be a recommended procedure to compress, invert and release new shocks to properly purge the charging gas from the valving I never fully understood it nor know if it is actually necessary, but I remember doing it a few times and feeling a significant difference in damping on the second compression. Who knows, shot in the dark here.. and apparently it is still a thing: https://www.onallcylinders.com/2015/07/02/tech-101-the-hows-and-whys-of-priming-your-shocks/ also look at rear sway bar end link condition. I replaced mine at ~50k due to corrosion eating them pretty badly, to avoid a failure. If not, i'd be looking at every single suspension component on that corner from the wheel bearing to control arm mount bushings and everything in between

The noise I'm chasing is almost certain a wheel bearing, but the nearly empty rear diff has me questioning that now, so I'm do preemptive research. I found a bunch of RDUs on ebay, new and used, but there are more versions of it than what the edge has and I'm wondering about cross compatibility and power handling capabilities.. like one for an explorer sport with the 3.5 ecoboost would have to be able to handle a lot more power.. So if it were bolt up possible and geared the same, it would be an idea to contemplate. New tires arrive today so I can emilinate that as a possible cause once they are installed.

all apologies for hammering this question.. but are those stock wheels? as in a 21" diameter 9" width stock ford wheel like used on the 2016 edge? or perhaps your year is wider? I only ask because it is kind of stated earlier that this is on stock wheels, but that width tire on a 9inch wide wheel is not a compatible/suggested match according to every site I've looked on Thanks again for the information

There were some small shiny bits but pretty minimal. I figure I'll run it a bit and suck out the old and refill. I've already started searching for RDUs and there are a bunch available out there, but minimal info on them. Any resources you can point me to on that would be appreciated

It's a 2016 sport with a hair over 92k on it And really that's not too much on the magnet. I mean none would be ideal, but I've seen much worse. The fluid top up has not changed the noise much, if at all, so it's likely that I will end up needing to do the wheel hub.. but I've expected that for over a year. Ironically the dealership said they could not replicate the problem when they had it for the brake line recall 18 months ago, which just pissed me off. Just joking here, but the thought occurred to me to take the bad part, once its been replaced, and heave it through their front window and ask if they can find the problem now ?

So, i've been chasing a sound like a rear wheel bearing or oddball tire tread wear pattern was making a sound of a howling from the rear, right side i think. I have the hub and hardware but i wanted to look hard at it before i dove ito that task and make sure it really needs it. Zero play in the wheel, no oddity to the tread.. WTF? So I jacked it up further and rolled under to look around. Discovered that the RDU right side output seal has been leaking and the pumpkin is chunky with adhered dirt stuck to the once active leak. Pulled the fill plug, which was furry with fine metal filings, and added fluid.. and it took a lot more than I expected it might. Like about 1/2 quart.. and it only holds 830ml.. +/- 30 I'm hoping its not damaged too badly, but i guess i need to start looking for an RDU

As a mechanic, I think you have good reason to be skeptical of anyone who lays hands on your vehicle until they prove themselves competent, either through your own experiences or referrals & reviews. There are some talented people in the business but there are a lot of hacks too.

while this would not locate or resolve the cause of the problem, this idea may work as a solution to the battery going dead.. have you considered a solar panel on the dash board to charge the battery while the car is parked & counteract the parasitic draw?

sounds like your calipers could be hanging up, as if, perhaps they did not use the proper procedure to retract the rear pistons with the electric park brake using a scan tool? hard to really say from minimal information.

when you pushed back the pistons, was there a significant difference in the amount of force required? (this would be bad) were the caliper slides free moving or hung up? also, the caliper brackets that the pads ride on, did you notice more or less rust on one side than the other? Did you open the bleeders and push the old fluid out? (you should always do this) If the pistons on one side were very hard to push back, that could be the beginnings of a sticky caliper, or caliper slides that don't move freely, either can be a fair reason to replace the caliper, though a sticky slide is easy enough to cure. the pad contact surfaces at the brackets (IDK if yours have the shim hardware or not) should be dusted over with a file regardless to knock any rust snots off, so the pads can move freely. if any rotor surface is even a little rough looking or rusted / rippled, then change the rotors, as that can effect wear rates. "NEED" to replace is a hard judgement to make from a minimal description, and its your life, so its your call, BUT i'd say if you can afford it, never cheap out on brake hardware. Any doubt, swap it out.

I should point out, my edge is a 2016, and does the power clutching at the RDU if I'm not mistaken, so a unit swap would not work for me to add cooling. I've toyed with the idea of s turbo blanket and wrapping the rear pipe but not done anything yet. I am running the Redline lightweight shockproof fluid in the PTU so I tried to find the service temp range spec but found nothing on that.

On the subject of PTU temperature.. I took a therapeutic ride through the dragon today with my OBDlink adapter in and the app running to monitor data afterwards. in the attached pic, you'll see the PTU temp peaked at almost 270°F, and actually possibly higher since if the measured temp exceeds the range of the virtual gauge, it stops at the limit of the display. I am 95% sure that the heat at the PTU, at least in this instance, is from heat soak off the rear turbo. Ambient temp was around 70. Head temp got over 240 even though coolant never got over 205 (170 thermostat installed) Amyway, point being, i wish mine had a cooling feature..

thank you for bringing this thread up from the depths, its adding more options for my next tire/wheel combo

Right, and paying for instalation probably makes it less of a value, if it is something you can do yourself.. which I'd say most people can.

No, it smelled like old used oil. And I'm not being a wiseass, that is a definite smell. Hydrocarbon combustion, pressure leakage past the rings (which is unavoidable to some degree, especially in boosted applications) create a distinct smell.

92k miles Oil and filter Summer /winter wheel swap Rear pads and rotors (Raybestos Element 3) Drained the catch can again, had about a tablespoon of very dark, thin, oily crap.

So I just did the spring oil change, and there was still a significant film of oil on the rear side of the pan near the PTU, but I realized I did not wash it down with brake clean after tightening the pan last time.. so I washed it down this time. 6Quarts came out and I don't recall adding any in the last interval, so if it is leaking it was not significant volume.

That is just wrong...