Contour Enthusiasts Group Archives Forums General Troubleshooting ATX/Diff Noise - Best way to go

My 98 2.5l/ATX Contour is making classic differential bearing noise - rumbling up through 50-60 KPH, decreasing in noise and then with a slight higer pitched howl abouve 90 KPH. More noise on turns and when braking (Wheel bearings and rotors are all new). Now the transmission has always had a significant buzz/vibration in it when accelerating from rest even when under warranty (have 169KM now)which I assumed was wheel bearing problems. Vibration was felt through steering and through gas pedal as it is now with some noise. I took it ind for service and even when wheel bearing were replaced under warranty I complained to the service rep at the Ford dealer at the time that vibration was still present at low speed. The answer back at the time was that my snow tires tread configuration was the source of the vibration which I disagreed with but did not press as vibration was transitional.
Now that the vibration is getting worse is it worthwhile or even feasible to go back to the dealer and complain for Ford to do the work it should have done when under warranty. It may be a long shot but worth a try. However if they turn me down do I still have Ford replace the tranny or go to a transmission shop and if so which ones are good (in Toronto area) Any experience GTA people?

FWIW, My ATX tour had similar noises and some vibration felt through the steering. After replacing one wheel bearing and starting on the second one (DS) I discovered that the inner CV joint was worn. Once the steering knuckle is off (like for wheel bearings) the axle is not hard to replace and is under $100 @ Napa. These front end noises can be hard to pin down, so getting a second opinion would probably be a good idea, especially before doing any tranny work. If you have papers to show that you brought this exact problem to the dealer and that they did not fix it while under warranty, you *may* be able to get some compensation, but you'll need to negotiate carefully.

Doubt if its the trans,more like CV joints re worse on turns.....

Thanks for the reply tw0wheelin. You may be right. The noise is very prevalent when making turns or rather putting lateral forces on the drive shafts. I assume a certain amount of force (side as well as rotational loading) is pushed back up through the CV joints. The half shafts are reasonable enough to repair and I have done it on other vehicles. The outer CV joints are easy to diagnose but inner ones are so close to everything major in driveline, it is hard to dtermine root cause. I forgot to mention that when up on jack stands and well blocked for safety, after putting car in drive no abnormal noise is heard in drive train even when pushing 'speed' up through 100 KPH. It would appear real drive forces are required to force the issue.
The question is how does one tell. I suspect that I need to take it in to Ford to tell me. How did you determine is was inner CV joint?

When the wheels are spinning you can look at the shafts.

When the wheels are straight, and there is no play in the Inner or Outer CV Joints,
the shaft should rotate without any other movement noticeable.

When the Inner joints go, the shaft will be loose, and you can see it spin in an elliptical fashion.

This elliptical movement will be even greater when the wheels are turned.

Also could be a bad tranny mount. Many ATX Contours rubber mount sinks a little allowing the tranny to bump and vibrate against the engine carriage. You can place some washers under the vertical bolts to shim it up a little. The mount costs about 75 bucks. Crawl under the car and check the clearance. Sometimes they bump a bit when starting the engine. Feels like something is loose under your feet.

Sometimes I feel a bump, though not normally when starting engine, just when shifting sometimes or when turning air/hear on. what's this?

That sounds reasonable RoadRunner. Of course a manual inspection of play without the engine running and transmission in drive would be prudent to begin with, then an inspection under dynamic conditions. Is there not also an intermediate shaft bearing on the right side driveshaft that also may be suspect?
It does not sound like the transmission mount (but worth an inspection) since noise only occurs with vehicle motion. The vibration (rotational) can be felt at low speed almost like a buzz up through the steering that has a dragging kind of quality to it. It feels as if something is tight within the driveline. Some days worse than others. The noise builds to a loud thrumming up through 60 KPH then mostly goes away to turn into a slight background howl which increases over 80 kph. Turns ins and braking accentuate the noise at all speeds but more so a lower speeds, worst being in the 55 to 60 kph area. It is definitely not wheel bearing since the local Canadian Tire has changed them under warranty twice in the last month (they give a lifetime warranty when they install them).
Anyways if it is the inner CV joints it will be a relief to have them fixed. I have changed half shafts on Chrysler minivans and other front wheel vehicles so it is just more of the same old stuff.
Personally I think real wheel vehicles with proper weight balance are easier overall to drive and maintain if one keeps all the toys to a limit. It is a lot easier to work on ttransmissions and front suspensions of cars with the driving wheels at the rear. An I don't think the packaging is any worse. BMW seems to be doing fine with it's product line.