Yet another rear diff question...

[Recoil Rob]

I know there's a lot of info posted on this forumand I did my best to figure it out so bear with me and help if you can.

Truck is a 2002 w/40,000 original miles, I just noticed a leak at the rear diff. I'm not sure if it's the cover gasket or the pinion gear, I'll get down there tomorrow to find out.

In the meantime am I correct that the Axle Code on my drivers door, being "45", denotes a conventional axle, not a Limited Slip?

Am I correct I need to top it off with 75/140 oil and friction modifier is not necessary?

I see some oils already have friction modifier in them and claim they are fine for conventional diffs, is that true or will it do harm to use one of these?

Finally, when refilling after draining, 1.5 qts should do it?

thanks for your patience.

Rob

 

[TechGuru]

Ford Friction Modifier is not needed if you are sure it is not a LSD.

I would use Lucas 75W-140 Gear Oil.

No need to measure, fill until it's level with the bottom of the fill hole or dripping out of it.

 

[Recoil Rob]

Thanks Guru, I got under today and saw that it's the left rear axle seal leaking. I did some Googling and find it was probably a factory defect as it seems a lot of people complained about these seals leaking with low mileage.

As much as I enjoy doing auto work (maybe not) I draw the line at power train/ suspension stuff. Brakes and other stuff OK but I don't have the tools or inclination to start removing rear axles. I have an appt with the local Ford Service for Thursday to have both sides done. I've read the original seals were 2 piece and leaking was a problem. they have replaced them with 1 piece which should last a while.


thanks,

Rob

 

[drdoom]

I don't know about an '02 but my '05 calls for an 8oz overfill through the ABS sensor port. YMMV

 

[TechGuru]

I don't know about an '02 but my '05 calls for an 8oz overfill through the ABS sensor port. YMMV

Hmm, Mitchell1 OnDemand 5 is showing 3.5 pints (1.75-1.80 quarts) for all 02-05.

I have no idea if that comes to at, below, or above the fill hole.

 

[drdoom]

Tech that checks out with an overfill, I had about six ounces or so left out of the two quart bottles I used to refill my open rear axle.

 

[TechGuru]

Tech that checks out with an overfill, I had about six ounces or so left out of the two quart bottles I used to refill my open rear axle.

Considering the fill plug has a magnet in it, it would make sense for it to be submerged by it being filled to the top of the fill hole.

I guess this means mine is low since I only filled to the bottom.

 

[drdoom]

I have the Ford dealer workshop manuals, and I went by that. Fill to bottom of hole, reinstall plug, then add 8oz through the sensor port.

 

[imp]

Considering the fill plug has a magnet in it, it would make sense for it to be submerged by it being filled to the top of the fill hole.

I guess this means mine is low since I only filled to the bottom.

This is pulling the goose's leg. Don't you think, picturing those gears spinning round and round, that the entire interior of the housing is constantly bathed in oil?

Picture it, tell me I'm off-base, and I'll move on. I'm believing you two guys are my knowledgeable equals here. DON'T TAKE OFFENSE, OK? imp

 

[TechGuru]

This is pulling the goose's leg. Don't you think, picturing those gears spinning round and round, that the entire interior of the housing is constantly bathed in oil?

Picture it, tell me I'm off-base, and I'll move on. I'm believing you two guys are my knowledgeable equals here. DON'T TAKE OFFENSE, OK? imp

You're off base. lol

When moving yes you are correct but once you park everything is well mixed and if submerged that magnet can draw suspended particles to it. If not submerged that magnet won't be doing anything when parked.

Ideally the magnet should be in the bottom...I checked the drain plug for one and nope...

 

[drdoom]

Correct. The the fill level height increase by the overfill is minimal, probably 1/4" or less.