Stuck differential fill plug, filling through vent.

A $10 propane torch should get you enough heat to unstick the fill plug.

how do you know that you need to put fluid in the rear end?

"187" wrote in news:006a3001ebc657684a0777e703022ec8 @localhost.talkaboutautos.com:

More importantly, how will he know if he's putting too much?

What about having the local welding shop weld a fill plug bung in the diff. cover while you have it off? You could mark the cover at the level of the old fill plug and have the shop weld the bung there. Problem solved.

If you can't get the filler plug out how do you know the oil level is low, and more importantly how do you know the correct amount of oil to add. I would under no circumstance make a hole in the differential to glue a WD-40 straw as a second vent hole. Get someone to heat the plug and remove it.

Since the cover is bad anyway, either buy a cast cover with a fill plug in it. Or take the new cover to a welder and have them weld a fill plug bung into it. DON'T add a new vent. It WILL leak when the gears start turning.

Most rear diff.'s have no vent, it is presumed that the correct amount of gear oil is added to prevent pressure. Get a new plate, they don't cost very much, with the standard drain plug. If you looked at the manual, you loosen a few bolts on top, which allows enough air seepage to drain the fluid easily. Then, it a matter of pumping enough oil into the drain opening to leak back out, BUT>>> have someone turn the wheels while the diff. is geared to transfer oil through the shafts, do that for a say 3 minutes. After that, top off the gear oil into the drain plug until it leaks out again.

Why do ya think there is NO vent plug in rear diff. covers? [for most rides]. The idea is to get the lube to the drain plug level, and that is usually the max. level required for the rear pig.

This is just so stupid that it deserves a reply. All diffs DO have vents. The purpose of the vent is to keep the gear oil from being pushed out past the seals when the diff gets hot.

Get a new plate, they don't

No need to loosen any bolts unless the cover is going to be removed.

Then, it a matter of pumping enough oil

WTF ??? What are you talking about ? There is no pump. There are no shafts for the oil to travel through. The differential is splash lubricated by the ring gear slinging oil around as the vehicle is driven.

After that, top off the gear oil into the

Because the vent is in the housing so you don't need another vent in the cover. Also, if the vent was in the cover it would most likely leak from the ring gear throwing oil at the cover.

Dumb question time...

How will you know when it is 'full' if you are 'filling' it from the vent line?

The full 'indicator' is the plug hole... and gear oil coming out there when it is 'full'.

Full doesn't mean 'full, you know. I think you need to get that plug outta there and do this right.