I have a 1999 Mercury Grand Marquis. i noticed a little diff fluid coming from the right rear wheel. I changed the wheel seal and axle bearing and put it all back together and filled the rear diff with 80/90 fluid as per the owners manual stated. I did not change the axle or any seals in the rear diff. Since, i have noticed a strange sound in the right rear tire. it sounds like a unbalanced tire jumping as i drive. i checked the tire and it is fine as well as the rear diff fluid. the noise starts around 30mph and continues untill i reach 30 or below mph. the car does not shake at all, just the noise. Any idea's?

SOURCE: clicking noise front driver side after repairs

CHECK THE LINK RODS

SOURCE: 2001 Mercury Grand Marquis hesitation and jolting from 35-45 mph

Sure, the more the throttle and the longer its open the more gas is being injected so if the spark is not there it will spotter. I think you have nothing to loose with an ignition tune-up. It'll be more economical than taking it to a mechanic and still ending up with the same problem. You should change the fuel filter also it could be clogged and there is'nt enough fuel delivered at these speeds. You can also try a fuel injector cleaning solution the kind you pour in the gas tank. This might work for you.

SOURCE: how to remove rear axle from a 2000 mercury marquis

Open the rear end, and take out keeper that holds the axel in..

if you push on the axel a bit and feel it slide into the rearend, that will show you the keeper at the other end...

Remember to have a catchpan under the rearend when takeing the cover off, as the fluid will drain out, and make sure to replace the fluid, (can't tell you how many get in a hurry and forget that part) Check with Ford to make sure what type fluid it is, (synth mix, full synth, or standard 80/90)

SOURCE: i have a 2001 mercury sable. when the car is

Take a spray bottle and put water in it and with engine running start spraying around the vaccum hoses and manifold intake, even ignition wires and coils...you are looking for vaccum leaks of some kind, or electical leaks. If the engine levels out at any point that you spray, inspect that area for a bad hose or leaking gasket. If it gets worse around the electrical wires, coil, ect, you can replace that componet. You will be able to buy an empty spray bottle at Automotive stores.

SOURCE: My 1978 Mercury Marquis

hi,

make sure your vacuum advance doesent have a slow leak, attach a spare piece of vac hose to the vac advance mod on the distrributor and s u c k on that hose., it should hold air and not leak make sure you dont have any other vacuum leaks. the vac mod on the tranny could have the same problem. open the jets on the carb a little by turning counterclockwise, you see the engine mellow out. theres two screws up under the front of the carb might need a rebuild, fuel filter could be half clogged. and then re time the engine..

jm