I have an '01 Crown Vic LX that started having a noise some where in the rear axle area. It started about a month after the car was rear ended at a stoplight; maybe coincidence. Only damage found was rear bumper and bumper "shocks", and this was repaired. Tires are all season with about 40K miles, less than half tread remaining. Wear pattern is normal and even. Noise is (best description) a "wuh-wuh-wuh. It seems to start around 40 mph, but doesn't stop until until the speed has dropped to about 25. Applying brakes or "feathering" the park brake does not change sound. Over inflating all 4 tires does not change the sound. There is no clicking or clunking or grinding sound. Low speed "donuts", cc or ccw, make no noise. Rear air bags were replaced with spring and shock kit back in summer. It seems that the noise lessens at interstate speeds. Any ideas where to look? Thanks.

 

Check for oil from the rear axel area on the tires
my 01 started making a whoop/whoop sound on a long trip..was worn out axels ans bearings..seals
I ran over a dead deer on the turnpike ..that seemed to start the problem..500 miles futher the rear bearings and axels were junk

 

Thanks. It was the rear axle bearings. Had to replace them both with the "bearing repair kits", because they had started eating the axles. Mechanic said this was caused by spinning the tires. A friend borrowed the car for about 3 weeks; during that time, the alternator went out, then the axle bearings. We don't make a habit of spinning the tires, but said friend got the car stuck and no telling how much spinning was done then.

 

those cars ain't hot rods. they were meant to be drove by little ole lady's unless it was for the police or hp

 

My Crown Vic has 260,000 miles..the Vic is built tough..and I am 63 ..so im a little old man (and dont hot rod any longer )..that said..parts wear out..fix it and roll on
Both axels were replaced along with bearings and seals..and it made the trip back to Texas from Illinois getting 27 mpg running at 65/70...car has new tires ,brakes, hoses, belt,new high flow cats and 3x18 glasspacks necked down to 2 1/4.180 deg thermostat E3 plugs and homebuilt water vapor injection, K&N filter with modifyed air box
Im a semi-retired mechanic..so I tend to tinker with it some..

 

Your mechanic doesn't always know what he is talking about. These are heavy cars, but can take a lot of abuse. Why do you think the cops use them? Now if you were jumping over high spots in intersections or a bridge, the weigh going back down on those axles after being airborne will cause the bearings to really go bad. But like everything else, the bearings do wear out. You just rebuilding the parts until about 300,000 miles then get rid of the car when you see the road at your feet.

 

I did auto/truck repair from '66 thru '87, so I am fairly familiar with motor vehicles. The '01 Vic in this story has the Performance and Handling package, minus the air suspension, which was replaced with springs. It has 153K, and my wife was driving it daily; she's 62.
My other Vic is an '03 P71 with Street Appearance package. It was a detective's car, and was not slammed around like a cruiser would be. It has 114K. Naturally, it handles and rides much better than the '01. We've both been using it more lately since it's "newer" and has less miles.And I'm 65. Neither of us poke around town with these cars. We run the posted speed, usually more. I used to run the P71 pretty hard, but have stopped that for the most part.
So I know how tough they are, especially the P71. I know that some spinning is not gonna do any damage, but these axle bearings (not just in Fords) should be better designed, instead of the bearing running directly on the axle with no inner race at all.

 

[quote=littleman;72538
So I know how tough they are, especially the P71. I know that some spinning is not gonna do any damage, but these axle bearings (not just in Fords) should be better designed, instead of the bearing running directly on the axle with no inner race at all.[/quote]

It's a shame what the penny pushers have done to the market. I guess that explains why so many racers have custom rear-end assemblies made for them. A good axle with pressed-on bearings running on an inner race in the tube would make one hell of a strong axle assembly. But they just wanted to save pennies. Look at the Pinto. What was it, a 75 cent rubber covering over the bolt would have prevented all those fires?

 

It would be nice if these full size RWD cars came with full floating rear axles, like in mid to full size trucks, IMO.

 

you may be dealing with a worn u-joint, rear end gears or bearings. something like getting rear ended. puts a shock into the car/drive line.. the frame may of been pushed in some. not enough to visually see any changes. enough to change alinement of moving parts… which can cause a component to wear out quickly..

i had a steering box give out about 6 months after having a low speed head on,, on a icy road. no visible damage to a tire or wheel.. all damage was in the bumper. (jeep wrangler) just used a pipe to straighten the bumper until a replacement arrived.