'89 Lo3. When I am going 40+mph and i push on the gas pedal, there is this high pitched tone emmitted. When I let off the gas, it stops. My moms '02 Ford Explorer did this and they had to rebuild the rear end. Why is mine making this noise?

 

how much fluid is in your rear differential?

 

Dont know

 

There should be a fill plug and occassionally a drain plug as well. If you take the fill plug out and stick your pink in it, if it has less than up to your last knuckle (the one right by your nail) then it's too low.

Also, rear diff fluid is very clear when put in there. If it comes out sludgy or something then you will want to replace that anyways. I find that rear differentials are the most neglected part of a car.

 

There's oil in the rear end?!?!?!?

I never knew that.

Learn something new every day, I guess.

(I'm kidding, just kidding!)


Where is this "high pitched tone" coming from? Up front? Out back? Can't tell? Is it only in a certain gear or at a certain RPM or at a certain MPH?

I wouldn't necessarily jump to the conculsion that the rear end is going out based on what little info is in this thread.

 

It seems to be there at all speeds, but only when i have my foot on the gas pedal. Im not sure but i think it is loudest at 40-50mph. I realy havent drvin in faster than that yet, but i think it might actually get quiter past 55mph. as soon as i let off the gas, it stops.

 

If coming from up front you could also have a vac leak...

 

Im pretty sure its coming from the rear of the car, and is loudest at 45mph