Growl/Rumble - Not Wheel Bearing

[Retroboy1989]

I'll try to make this short. I'm trying to diagnose a growl/rumble that starts at about 20mph and is most noticable at 35-40 mph. Any faster and I don't hear or feel it. It is not the wheel bearings or the front driveshaft.

I first noticed it 200 miles after installing a rear limited slip. The logical conclusion was that something had gone bad in the install. I waited untill 500 miles and pulled the rear end apart. I removed the carrier and inspected the new bearings. Everything was smooth and tight. No damage the the bearing surfaces. I installed new rear wheel bearings after that for good measure. No change in sound.

I moved to the front. I though the sound changed slightly with steering, so I replaced the front wheel bearings. I also noticed slight play in the lower bjs so I replaced those as well. This tightened the front end and I thought I had fixed it, but within a few days I noticed the growl.

As a test, I drove down a straight wet roads locked in 4wd. The growl is much louder and comes with vibration around 20-30mph. There is a loud growl/howl under hard acceleration or deceleration.

I removed the front driveshaft. There is no noticable difference in sounds. This should eliminate the ds and tcase as suspects.

At this point I do not want to spend any more money without a firm diagnosis. My gut tells me front carrier bearings, but that seems to be a really rare event from all my searching. My truck only has 50k miles on the clock.

No play in front pinion flange. The front gear oil looks clear, but there is no magnet on the fill plug to catch filings.

Any thoughts?

 

[CDW6212R]

What does the TC fluid look like, and had it been changed ever before? Pulling the front drive shaft eliminates the shaft joints, but the front diff, and TC can still be the issue. You changed the front hub bearings, what brand were the new ones just for the hell of asking?

I'd double check things, start with the front brakes as that's easiest. Be sure nothing is interfering with other parts etc. A bearing noise can be from an area far from the noise appears to come from. You've addressed several things, maybe one of those is still the issue.

I had an engine miss ten years ago that ended up being a coil pack, which was new 2-3 years earlier. I changed many tune up items just to be thorough, and then began swapping parts around. The coils were the last thing I tried, Accel parts I'll never buy again. They are on my black list, a coil should not fail in less than 6000 miles and a couple of years old.

 

[Retroboy1989]

I looked over the brakes when I did the hubs and I didn't notice anything odd. It is worth another look. The tcase fluid was new one year ago. It's the Valvoline full synthetic transfercase fluid. The bearings are timken.

I was tempted to remove the front diff and CVs to see if that eliminated the growl, but apparently it's not safe to run without the axle nut torqued on the hub.

I am considering dropping the diff and inspecting the carrier bearings, but I don't have much time to wrench these days.

 

[CDW6212R]

How did you see the gear oil in the front, you said it was clear? With that low mileage, it's hard to point at things that might have wear/age etc. We need more symptoms or clues.

 

[Retroboy1989]

I keep wondering if all of this is a result of the Torsen i put in the rear end, but I tore that apart at 500 miles (300 miles after the sound started) and I everything was tight. The bearing surfaces looked good and everything rolled smooth. I used Timken bearings in the rear as well and I did not touch the pinion. Backlash was identical before and after the swap. .011.

I pulled the front fill plug and the stuff that dribbled out looked brand new on a paper towel. I changed in the Fall of '18 with the Tcase. Is there a magnet anywhere in the case? I am thinking about buying a magnetic plug for the front.

I am dealing with a 20mph rumble and a drone/growl from 30-40mph. Above 45, it either goes away or is drown out by road and wind noise. I can feel it slightly in the floorboards.

As far as clues, i put the front driveline back in. Here is what I am observing:

No front drive line (Tcase in 2wd or 4x4): same 20mph rumble, the 30-40mph growl hardly noticeable, but definitely there
Front drive line installed 2wd: same 20mph rumble, more noticeable growl
Front drive line installed 4x4: more 20mph rumble, more driveline noise and vibration, the growl/drone is loud at speed especially under accel or decel.

My working theory is this: removing the drive line took some drag off the front diff, so it quieted down. The opposite is true when locked in 4x4.

I have been doing some reading about the CV support bearings on each end of the diff. I am tempted to pull the CVs and inspect those, however there is no leaking, which makes them unlikely. I will at least crawl under and inspect for play in the inboard CVs.

How does the intermediate shaft come out without opening the diff? I find very little information on the Dana 35 SLA teardown.

I did run my Dana BOM number to confirm i have the D35 and not the Super 30 that were found in some 01-05 SportTracs/Sports. So parts should be easy to match and source if I do get into it.

I also noticed Ranger 4.10 diffs are a dime a dozen on ebay if it came to that. Some of them have under 80K on them, but then I look at my own with 50K and wonder what I am missing.

Thanks

 

[CDW6212R]

That's a good list of steps taken. With that low mileage again, it's tough to think of something, everything coming to mind is mileage or age related.

I'd see how tight the front diff/case is though, be sure it doesn't move around much in any direction. The three main bolts are easy to check, but with age the bushings get worn and a bit loose.

If nothing else turn up an issue, I'd consider replacing the front hubs, which are an item that can have bearing noises/feel, without external clues. I've only had four bad hubs over the years, but all of them were higher mileage. My Crown Vic though had two new ones go bad in less than two months each, defective obviously.

 

[Retroboy1989]

It has been some time with me driving and listening to the annoying growl. No new symptoms, but I have done something crazy:

I bought two refurbed CVs off rock auto on clearance cheaper than the $30 the junk yard wanted I then swapped out my CVs for the stubs from the refurbed CVs to apply the proper preload to the wheel bearings. I also put the inner cups in the differential to keep oil in and dirt out.

I have not had a chance to go for a drive yet, but I did notice something that seemed odd. When I spin the differential by one of the cups, I hear and feel gear tooth noise. Quite a bit of it. I would have expected the differential to be fairly smooth and tight. Does this sound right?

The swishing noise is the lip of the outer seal. Listen for the growling that almost has a metallic ring to it at one point.

The front drive line was not spinning as I turned the cup. The carrier bearings should be stationary, ring and pinion stationary. The only moving parts should be the support bearings and the spiders.



Ill take it for a drive in the next few days and report back.

 

[CDW6212R]

That sounds dry, have you checked the grease level lately?

 

[Retroboy1989]

I agree it sounds dry. I pulled the fill plug and oil dribbled out when i started investigating this.

Also, there is not any oil buildup to indicate a leak anywhere.

 

[CDW6212R]

How did the grease look, did it look to be clean, or dirty/fouled with metal at all? With that noise I'd be making plans to drop the diff, and pop the cover to see the gears etc.

Does the rear pinion shaft move side to side much, and how much play is in the gears? It is common to be able to turn the pinion a little more than you'd think is right, so that is a tough gauge to trust.

 

[Retroboy1989]

When you say grease, do you mean gear oil? The stuff that dribbled out from the fill plug looked as clean as the day I put it in two years ago.

There is no lateral play in the pinion. I'll see how much lash there is. I agree the diff probably needs to come out. With my little setup I can drop the diff and keep using the vehicle. It's basically a 2wd now.

 

[Mbrooks420]

It doesn’t rule out the t case as it’s all still spinning inside. Same with the front axle. Removing the front shaft only rules out the shaft itself.

 

[CDW6212R]

Ditto, the noises can easily be from a connected part. I had a growl in my Mountaineer in 2003, Christmas Day. I had spare hubs and axles, so I put the two left ones in. That didn't fix it, and I pulled the front drive shaft. My front diff sounded okay by hand, so I figured on the TC or the front shaft. It turned out to be the CV joint of the drive shaft, and the boot was intact. I'd have sworn the noise was from the left front are. Many people have done that and found the issue elsewhere later on.

 

[ptf18]

Retroboy.... This is wwwwwayout there. In 2002 the wife bought her NEW S/T (still has it). At about 12-13k on the dial the S/T developed a "noise" similar to what you are describing. We had the dealer look at it a couple of times (just before the warranty expired) and they found nothing wrong.

Poking around the internet (2002/03) I came across a couple S/T web-sites...maybe this one..... who's members were posting questions about "unusual noises and vibrations" they were experiencing with their S/Ts. Have to remember that the S/T was relatively new to Fords lineup.

Won't go into the LONG story about what alot of S/T owners were dealing with... "unusual noises and vibrations" but what was the cause of the problem was Fords use of the Ranger P/U front end on the heavier S/T. The symptom was not only "unusual noises and vibrations" but ALSO weird front end tire wear. (cupping of the inner tread...very hard to see unless you ignored it). Ford "fix" was to tell its S/T owners to rotate the tires at every oil change (3k). Total BS as far as I was concern.

In the end, what many of us "problem" children did to really "fix" this issue was to install better quality shocks and get the front end adjusted to different specs than what Ford said to use.

Our S/T has 240k on the dial. Its a 2 WD so perhaps your problem is something else. But the "unusual noise and vibration" along with cupping of the tires is a very distant memory.

 

[Mbrooks420]

I’ve always used to have trouble keeping the front end aligned. My solution was to plan to rotate my tires every 5k. I’d run the tires for a year, have 25% tread in the front, and cupped. Rears at 50-75%. Then, I’d buy new tires. Young and dumb, I guess.

Oh, I’ve got 50k on my TAKOs. Any bets on current tread front and rear?

 

[ptf18]

Mbrooks420.... As per my post..... We haven't "cupping" issues in many many years. I rotate the tires every 10k Tread wear is pretty even across on all 4 tires. Another "thing" was the method of rotation. I use to go front to rear and when I was having the weird cupping issue (that would be very noticeaqble by 2500 to 3K miles) another "recommendation" was to "cross rotate" the tires which I was "directed" to find the instructions to do so IN MY OWNERS MANUAL.

 

[CDW6212R]

The front alignment has a ton to do with front tire wear. I think the camber has the most to do with it, that's easy for a shop to get wrong or too far from where it should be. That also needs to vary by the driver, highway use needs zero camber, hard driving in turns needs much more negative camber.

I have extra wear from tons of steering at low speeds, usually one front wears faster than the rest for me. Right now on this white 98 it's the right front, my black one was the left front(same alignment shop etc, same tire sizes, same rotation time and method, same driving conditions). I'm having am interesting time now with snow tires, I put on these close to two months ago, being over ten years old, they need to be used up. So far they are wonderful in all rain, but as expected the rubber is being eaten fast. They looked like new when I put them on, and now they look like they have about 1/4 tread left. I give them a month before I'm thinking of yanking them.

 

[matthfam]

I'll try to make this short. I'm trying to diagnose a growl/rumble that starts at about 20mph and is most noticable at 35-40 mph. Any faster and I don't hear or feel it. It is not the wheel bearings or the front driveshaft.

I first noticed it 200 miles after installing a rear limited slip. The logical conclusion was that something had gone bad in the install. I waited untill 500 miles and pulled the rear end apart. I removed the carrier and inspected the new bearings. Everything was smooth and tight. No damage the the bearing surfaces. I installed new rear wheel bearings after that for good measure. No change in sound.

I moved to the front. I though the sound changed slightly with steering, so I replaced the front wheel bearings. I also noticed slight play in the lower bjs so I replaced those as well. This tightened the front end and I thought I had fixed it, but within a few days I noticed the growl.

As a test, I drove down a straight wet roads locked in 4wd. The growl is much louder and comes with vibration around 20-30mph. There is a loud growl/howl under hard acceleration or deceleration.

I removed the front driveshaft. There is no noticable difference in sounds. This should eliminate the ds and tcase as suspects.

At this point I do not want to spend any more money without a firm diagnosis. My gut tells me front carrier bearings, but that seems to be a really rare event from all my searching. My truck only has 50k miles on the clock.

No play in front pinion flange. The front gear oil looks clear, but there is no magnet on the fill plug to catch filings.

Any thoughts?

I realize this post is four years old, but I'm hoping you got to the bottom of the problem and found what the problem was. I am having the same problem with my 2012 Ford Explorer. Did you find the problem?

 

[matthfam]

I'll try to make this short. I'm trying to diagnose a growl/rumble that starts at about 20mph and is most noticable at 35-40 mph. Any faster and I don't hear or feel it. It is not the wheel bearings or the front driveshaft.

I first noticed it 200 miles after installing a rear limited slip. The logical conclusion was that something had gone bad in the install. I waited untill 500 miles and pulled the rear end apart. I removed the carrier and inspected the new bearings. Everything was smooth and tight. No damage the the bearing surfaces. I installed new rear wheel bearings after that for good measure. No change in sound.

I moved to the front. I though the sound changed slightly with steering, so I replaced the front wheel bearings. I also noticed slight play in the lower bjs so I replaced those as well. This tightened the front end and I thought I had fixed it, but within a few days I noticed the growl.

As a test, I drove down a straight wet roads locked in 4wd. The growl is much louder and comes with vibration around 20-30mph. There is a loud growl/howl under hard acceleration or deceleration.

I removed the front driveshaft. There is no noticable difference in sounds. This should eliminate the ds and tcase as suspects.

At this point I do not want to spend any more money without a firm diagnosis. My gut tells me front carrier bearings, but that seems to be a really rare event from all my searching. My truck only has 50k miles on the clock.

No play in front pinion flange. The front gear oil looks clear, but there is no magnet on the fill plug to catch filings.

Any thoughts?

I realize this post is four years old, but I'm hoping you got to the bottom of the problem and found what the problem was. I am having the same problem with my 2012 Ford Explorer. Did you find the problem?

 

[oklagp1200r]

I realize this post is four years old, but I'm hoping you got to the bottom of the problem and found what the problem was. I am having the same problem with my 2012 Ford Explorer. Did you find the problem?

Yours a 4 wheel drive??
If so maybe the front hub bearings.