80W90 gear oil.Use a slightly higher number if you have excessive rear end noise,or mix a "little" Lucas oil stabilizer to it.Works really good.
You can also add a little bit of friction modifier.This stuff is generally used in differentials with posi,or clutches.V6 dont have this (one wheel peel...hehe) but this additive still helps control wear.
Put additive in first then fill with gear oil till it just starts to dribble out the plug hole.
Howdy,
I put 75/90 Fully Synthetic PAO stock based in mine w/friction modifier. I do have the TractionLok/Posi w/3.73 gears and a 9" Billet Stallion 2800 stall torque converter that puts approx 40% more torque to the rear tires. Tuned torque modulation, shift firmness and rpm times. If you're hearing noise you may want to get a new master bearing kit w/shims etc... If you just upgraded gears and you're hearing whine etc.. then they were not installed correctly and time to do it over. My .02 worth.
thanks for the info, i have no noise it was smelling like gear lube on long trips so i just figured i would change it out,knowing it has never been changed,is it necessary to add any kind of additive to it?
thanks for the info, i have no noise it was smelling like gear lube on long trips so i just figured i would change it out,knowing it has never been changed,is it necessary to add any kind of additive to it?
No it's not neccessary but it does help.It's only required if you have posi (or what Ford calls Traction Lock Axle) ..as in 2 wheel burnouts.I'm not positive on the exact reason,all I know is that the clutch in those types of rear ends need this to function properly.
You're smelling gear oil probably because the cover seal to the diff is leaking.Replace the seal while your in the process of changing the lube out.Carefully scrape old gasket material of the plate sealing surface.Make sure it's smooth and put new gasket and/or use copper rtv sealant.Last time I changed my geal oil,i didn't use a new gasket,i just beaded up some copper rtv all around and bolted it back up.I waited 2 hours before I added the oil to it to allow it to dry.
dont mean to steal thread here but to change rear end oil, would you just pull the gurdle and drain it. then put it back on and put new oil in through top???
dont mean to steal thread here but to change rear end oil, would you just pull the gurdle and drain it. then put it back on and put new oil in through top???
Gurdle? Not sure what that is,but if you mean rear cover plate on diff then yes.Stuff a wide catch pan underneath the diff and start lossening the bolts from the bottom side first.That way it starts draining out before you get the cover off;and also prevent from making a huge stinky ass mess.You will probably have to loosen about 3/4 of the bolts from the bottom up then carefully wedge at the bottom to get it unstuck.When done,best to fully remove plate,inspect gears,clean out then re-seal.Fill through plug hole on back side.