E-250 rear differential fluid change
 

Hello, I've got a e-250 van with the 4.2 v-6 motor. I want to change the rear end fluid and am curious what axle ratio I've got. On the driver's side door jamb, the sticker says the axle code is 24, what does that mean?
Also, any tricks to changing the fluid? There's a plug about 1/3 to 1/2 up the rear cover, but I'm sure I've got to pull the cover to drain the fluid? New gaskets? Should I use the Ford gear oil or something else? This van is worked pretty hard on a daily basis.
Thanks,
Jim

Fluid is synthetic, Ford fluid price is nuts, plus if you have a limited slip like me, you gotta run a friction modifier, holds 3 1/2 qts BTW. I bought Royal Purple synthetic gear lube from the speed shop, cheaper than Motorcraft, far better and needs no friction modifier. The cover needs no gasket, there aren't any, it's glued on, you use RTV sealer, it's hell to get off, so you have to work at it, chizeling around the cover until it finally pops loose on one side. Mines a 99 E-350, the tag bolted on one side of the cover, under one of the hold down bolts says 3.50 and limited slip.

To eliminate the possibility of an axle swap don't rely on the door jamb sticker, look at the tag on the axle itself.

That plug is the fill hole & establishes the proper fill level. Quickie rear end oil changes are sometimes accomplished by using a suction pump to draw out the old oil-I don't recommend it, but if your paying to have somebody else do it be sure to specify. When you remove the cover to drain oil properly you have a chance to inspect the ring, pinion & bolts, as well as clean out any debris that has accumulated on the bottom of the housing. Some place a magnet inside to collect any steel that might circulate. Older Econolines did have gaskets & my parts store was unable to be certain which gasket to sell me by the numbers! I took 2 & had to match what I found & return the other. Be sure you use the friction modifyer required for limited slip.