[ImperialCrown]

With the vehicle up on a lift and held to 55 mph, the technician should be able to locate the source of the rumble. If it is tire rumble, you will not hear the noise with the wheels off the ground. A rough tread surface feel while running your hand across the tire tread could confirm a tire noise.
If you can hear it inside the vehicle, you should be able to hear it and locate it from underneath.

 

[00Molavi]

I will have to put it on stands and test myself. I have been firing my mechanics (2 so far). But your comment got me thinking. FWIW this noise has been there despite tire change and the current tire is new. So chances are it is a bearing or something inside the differential. I had a 3spd automatic Corolla that did the same thing and they were notorious for differential failures.

 

[00Molavi]

I know it has been a while, but now at 140K miles, the rumble is yet again more prominent. Can not drive over 65 mph on the fwy without being annoyed. I have rotated the tires, balanced them, gotten two alignments and no change. These were mostly done due to a bit of pull which has resolved.

I put the car on stands today, I increase the speed to 50 mph and the whole front end is shaking-something that is not that obvious while driving. Could this be from the front raise on stands were not perfectly even? Does this give any clue where my rumble is coming from?

 

[ImperialCrown]

The rumble sure sounds like transaxle final drive (differential) bearings to me.
The front end shake may have been from the increased angle of the half-shafts when the jack stands were supporting the frame and the front end was allowed to hang down.
It may be unstable supporting the vehicle under the lower ball joints with the front wheels spinning and you underneath the vehicle to keep the half-shafts at a more normal road-going angle.
Please stay safe. A lift would be the safest way to raise the vehicle for this kind of diagnosis although I do realize that you are trying to do this yourself and save money.

 

[00Molavi]

Thanks Imperialcrown; I am more chicken than you think, did not go under the car. Actually no need to either, because the rumble is so audible from the driver seat, that I don't need to get under it. I guess the shaking is from the stands, on second thought, there might be a bit of fine tremor at high speeds too. All in all, you confirm my suspicion of transmission/differential bearings. I used to drive pretty beaten up RWD cars and this rumble is very familiar. Over the last 80K miles, I have been through a lot of tires and balancing, so it should have gone away at least once.

So, I guess, given the reputation of these transmissions, 140+ miles is not bad, and it is still driveable, just not over 65MPH. I was hoping that my frequent ATF 4 changes would do some miracle.

 

[chuzz]

Have you taken a close look at the cv boots and made sure that one of them isn't split and slung out all of the grease. I'm sure IC probably nailed it, but check the half shafts anyway. Maybe you'll luck out.

 

[00Molavi]

CV boot are fine. I will check the half shafts too. At this point, I think I am going to drive it until something happens. The mechanics around me have not shown to be very bright. I am not going to spend big $$$ on this car. Has had a lot of issues over the last 2 years and I have just babied it to no end.

 

[00Molavi]

Update;

Waterpump went and had to pay to fix because of my shcedule.

BUT, finally with some research, decided to tackle the wheel hubs just for fun. Logic; I could do it with loaner tools from Autozone. So paid for one hub and the noise got better. With the second hub change, now the car drives with no unusual noise. The rumble I had was not typical of wheel bearing noise at all. No wiggle on the wheel and no change with turning. So hopefully this might help someone else. Also I had a split opinion between two mechanics, one said it is the transmission and the other said wheel bearing.

As fas as the job; there are youtube vides on it. That helped. Actually the job was not as difficult as I thought, probably easier than the front brakes or on par. I was worried about the axle nut, so rented th 24" breaker bar and was ready to throw all the weight on it, but started to give with just slight push.

 

[chuzz]

If that axle nut gave pretty easily, then I'm going to suggest that they were not properly torqued to start with. I've replaced several axles over the years and always had to have a breaker bar to help. And I'm not a small guy at 5' 11" and 200 pounds.

 

[00Molavi]

If that axle nut gave pretty easily, then I'm going to suggest that they were not properly torqued to start with. I've replaced several axles over the years and always had to have a breaker bar to help. And I'm not a small guy at 5' 11" and 200 pounds.

I did use a 24" breaker br. Had never used one, so not sure how much leverage it adds relative to other jobs (other than the simple physics of it). I still say, from what I have seen on the internet videos, mine went pretty easy. I made sure I torqued in properly.