4.6L AWD strange rubbing/growling sound turning

[JB7795]

I just bought an 04 4.6L AWD Explorer in May and have since rebuilt the entire engine top to bottom and put a new transmission in among a few other things. No problems with the engine or trans, both work perfectly but I’m experiencing this strange rubbing/growling sound at low speeds while turning like in and out of a parking spot. It doesn’t sound like it’s a grinding noise though. I bought the thing for $500 after it’d sat in my friends parents garage for the past 5-6 years not running because of a bad timing chain and transmission being shot, needless to say the tires were in desperate need of replacement too dry rotted pretty severely. Fast forward to after I get all this work done, I go to drive it just around the area I live considering the shape of the tires (I know terrible idea on 6 year old dry rot) but I had an appointment to get new tires the following day so I wasn’t too worried about it and that’s when I noticed this sound when turning. I just thought maybe it was the tires because the tread was starting to separate etc. Next day I get new tires and an alignment and the truck still makes the same noise. Everywhere I’ve searched prior to making this post says something about tires or wheel bearings, but I’ve had wheel bearings go out on vehicles before and they’ve all pretty much made the same noises and behaved the same way. This isn’t a grinding noise, and it only happens at low speeds not when I’m turning on an interstate ramp or something. It sounds like the tires are rubbing on something but they aren’t I’ve looked up underneath for rubbing marks on the tires and chassis. Also it feels/sounds like it’s coming from underneath the whole truck front and back wheels, it’s not just isolated to the front driver or back passenger. I find it highly unlikely that all 4 wheel bearings have gone bad at once and make the same uniform sound. The only suspension work I’ve done is replace both front upper and lower ball joints, but the technician at the tire shop said my suspension was nice and tight so I doubt this really has anything to do with my suspension. I’ve never experienced this before so I’m stumped, usually a bad wheel bearing is easy to isolate to whatever wheel it’s coming from and makes the infamous clicking/grinding noises primarily when turning. Like I said before the closest thing I could relate the sound to would be like the tires rubbing on the fender or the steering knuckle. Hopefully you guys have some ideas ‍

 

[Hank102938]

I’m not super familiar with the AWD but if it has a limited slip rear diff it could be binding up. You may want to change out the gear oil, or if you already did, make sure to add friction modifier even if the oil said it wasn’t required. The limited slip binding up makes a groaning sound at low speeds in moderate to tight turns. It can seem like the noise/vibration is coming from the front too, not just the back, and through the floor or pedals. Other ideas: A bad cv axle. A locked up awd viscous coupling if you’re getting any binding or tire jumping in a tight turn,

 

[JB7795]

Okay thanks Hank! I’ll check these things out, it could be a cv axle but all of mine seemed to be okay no rips or anything in the boots. Also cv axles almost always make clicking noises while turning sometimes it doesn’t matter how fast or slow either, and since it feels like it’s coming from underneath the whole vehicle I’d probably rule out it being an axle. But I’ll have to look into that to see if I have the limited slip diff, and if so try changing out the oil and adding that modifier you mentioned. Where is this viscous coupling located though? In the transfer case? I haven’t experienced any sort of binding or tire jumping yet but I’d still like to inspect that coupling. Thanks again for the reply!

 

[94Eddie]

Another thing that can cause weird noises and behavior in AWD systems is if your tires are not all nearly the same circumference. It doesn't take much difference (3/8" I believe) to cause issues.

 

[Hank102938]

Here’s some good info on the viscous couplings in the explorers. It’s not necessarily specific to the 3rd gen. School Me (and you?!) On Viscous Couplings (BW4404)

Eddie’s suggestion is probably worth considering first before looking into much else.

 

[JB7795]

Okay, thanks guys! I currently have to replace the catalytic converters first then moving onto this issue. I noticed as I’ve driven it more on the new tires the noise has dissipated somewhat but is still present in super tight turns. Will report back what I find!

 

[94Eddie]

Another thing that can be done to trouble check is to remove the front drive shaft and test drive it. If the problem disappears then it is likely a bad viscous coupler in the transfer case.

 

[JB7795]

Hey guys just giving an update here, I still haven't been able to determine the cause of the growling sound because now I’ve run into a new issue upon re-assembling everything, when put into gear the vehicle will not move in either direction. When I’d originally finished rebuilding the engine and installing the new transmission, the truck ran great and I had no problems with the transmission but then realized the catalytic converter was shot (rattling like crazy, reduced performance) pieces of it actually came falling out upon removal anyways I order the new cat and the torque converter adapter alignment tool for the 4.6L’s. I hadn’t used one the first time when I installed the trans because there were very visible marks left on the adapter plate from the 8 nuts and I figured I had it centered on there pretty well. But got to thinking about it and it bugged me that I didn’t use it so I bit the bullet and paid $50 for the tool I’m gonna probably use once but I digress. Note I only drove this truck maybe 300 miles total before I pulled it back in the garage and tore the old cat assembly off and removed the transmission again so I could use that tool on the plate which ended up being spot on anyways but I still removed all the nuts and used it anyways for peace of mind. I did also drain and replace fluid in the front & rear diffs (included fords friction modifier) as well as the transfer case. So now I get in the truck expecting everything to be in tip top shape, put it into drive and the f***ing thing won’t move. I’m at a loss, checked all my connections, pulled the solenoid connector out and blew some compressed air in there and the plug in case some debris managed to get in there but still nothing. The shift linkage is connected and shifting the NSS lever as it should, truck won’t start unless in park or neutral, reverse lights come on when in reverse but the transmission does not engage. I can roll the truck back and forth in the garage in any gear other than park while the truck is running, transmission fluid is full too. What could possibly be going on now? *palm to face*

*edit* There is also this noise that seems to be coming from the bell housing like an occasional rattle/grinding noise which I noticed the first time I had driven the truck. I used my stethoscope and I’ve isolated it to the bell housing, could something being going on with the flexplate and torque converter that’s causing the transmission not to engage? I used my all data diy manuals for everything I’ve done to this truck following torque specs and bolt sequences down to the last detail so needless to say I’m very frustrated this evening, I need a beer lol

 

[Hank102938]

My mind goes straight to low trans fluid, but did you do anything after you had it driving where you drained any fluid? Drive shafts hooked up? I would assume if you didn’t have something wired up correctly you’d get a code, but I wouldn’t rely on that. Just suggesting some obvious ideas, other than that, .

 

[JB7795]

Okay I’m at work right now but will check the trans fluid again when I get home, I didn’t drain any fluid out of the trans considering it came filled when I ordered it all I had to do was add an additional 3-4 quarts as instructed in the pamphlet that came with the new tranny. I mean a little had come out when I removed the cooler lines but I would assume that little amount compared to the 12 something quarts that goes into this transmission wouldn’t cause it to disengage. I mean it doesn’t feel like the transmission is even trying to engage, it doesn’t feel like there’s any movement or engagement from the transmission. Driveshafts are connected, I did notice after messing with the truck for a while I got underneath and tried to turn the rear driveshaft by hand and felt/heard something click, is something within the transmission getting stuck?

 

[Hank102938]

You may want to create a new thread just for this new issue over here: Transmissions & Transfer Cases

Oh, and stop back here when you get back to your original issue, will be interested to know how that turned out.

 

[JB7795]

Okay will do thanks man! I’ll be sure to report back when I figure this out!

 

[Rynofx88]

I too have the 04 Explorer, 4.6L and experienced this same issue. It is definitely the limited slip friction clutch plates in the rear differential. Also, if it's back to running, try and observe if the (rubbing, grinding, shuddering) noise substantially resides after driving for awhile - possibly after the diff fluid warms up for 20 minutes, maybe sloshes around and coats things more. This is what I noticed on mine.

I would first do a fluid change to the diff and when you refill, add (2) 4oz bottles of the friction modifier. I think this ultimately helped me in the end. There is still a tiny bit of 'rubbing' when the fluid is cold - but absolutely nothing like it used to. If you decide to do a diff rebuild, then I would recommend researching a high quality friction plate set. I started with this solution, and found a OEM set on ebay that came in a genuine looking Ford box with genuine looking ford instruction that looked like they were printed in 1940. The new parts were exactly the same as the ones that came out, and the new set contained extra shim plates of different thicknesses. I should have researched this a little more, or asked a Ford mechanic his opinion on adding thicker shims back in - as I ended up just reinstalling the same thickness shims. (.025 if I remember correctly) I think what I ultimately did, was just swap out the old problematic clutch pack for a new set of the same problematic clutches, right back to square one. I think maybe there are higher quality sets with a better friction material, then pack them in a little tighter with thicker shims.
After all this, I still had the grinding shuddering noise, but at least I'd seen the inside of the differential and knew that it was in excellent condition. It's worth mentioning that this issue does not seem to do much if anything in the way of damage to the inner gears of the diff.

Again, try just doing a full fluid change and adding back in 8oz of modifier. I'll note that you can't just easily add an extra 4oz bottle to the already full case. If you've done a fluid change on this model, you'll know what I mean. If you try to pump into the overflow hole, it will most likely just drain back out. You can try siphoning some out, mixing in the modifier and pumping it back in, but by the time you do all this you could have easily just drained the old and added fresh new in the same 20 minutes and be certain there is plenty of modifier within the case. (Advice given from direct experience...)

Hope this helps.

 

[JB7795]

Rynofx88 — thank you for the info will definitely keep this in mind once I get her back up and running. I did change out the fluid as well as added the friction modifier but currently experiencing a new issue with the transmission not engaging so can’t tell yet if that helped or not. Engine runs amazing but that doesn’t mean jack if it won’t move lol! Will report back about this issue once I get the transmission to cooperate.

 

[Cj02mercurymounty]

Another thing that can be done to trouble check is to remove the front drive shaft and test drive it. If the problem disappears then it is likely a bad viscous coupler in the transfer case.

how much does this usually cost to repair

 

[CDW6212R]

how much does this usually cost to repair

Old thread here, but for the AWD cost, look up "BW 4410 transfer case." Given the cost, the tires should never be allowed to wear unevenly, that kills the AWD TC.