I have a whine towards the rear of my Aerostar when decellerating. My father suggested that I check the fluid level in the rear end. I remember doing this years ago with him in the garage on one of the family cars and all we did was remove a bolt in the differential and make sure the fluid level was up to the hole where the bolt came out. So I crawled under my van on Saturday to check and couldn't find the bolt for checking the fluid level.

Can someone tell me how I am supposed to check the fluid level in a 1993 Aerostart differential? I assume I will add fluid in the same place if it is low.

Thanks,
Drew

 

On the 8.8" differential, the plug is on the driver's side facing front. It has a 3/8" square hole, and you can use a 3/8" socket extension to fit into it in order to turn it. Make sure you hold the extension straight, as you may need to apply a lot of force, and I hear that square hole is easy to strip.

 

Excellent! Thanks. I'll crawl back under there and check it out.

For what it's worth, I noticed on the way home last night that the whine is when I decellerate not accellerate. If that rings a different bell for anyone, please let me know.

Thanks,
Drew

 

Once you locate the fill hole and remove the plug, use the "pinky method". You stick the end of you little pinky into the hole and the fluid level should be just below the fill plug hole.

The whine noise on coasting is most ikely worn pinion bearings. Sometimes the pinion nut works loose and causes the same noise. If the nut is loose, try re-torquing first to see if you still have the same noise.