How long can I drive like this?

It seems my rear differential is leaking. I plan to replace it but can’t get to it immediately. Is it okay to drive for a week or so? Should I add more fluid in the meantime?

Try to unscrew the fill plug (should be up high on the cast housing, with a square socket). If you can reach in there with your finger and touch the top of the oil you’re in great shape. Otherwise you might want to pump some more gear oil in there in case it has gotten really low.

I would say you’re at least safe to drive to the store and pick up the gear oil.

If this is pretty recent, I’m going to guess you’re still in good shape …but it’s hard to say without checking the oil level.

Honestly, I’m not even sure if mine has any fluid left… the rest of the truck will probably give out before the differential becomes a problem.

Depends on how much fluid is left in it. It’s an easy job to do

Just keep the gear oil topped off, and it should be fine. The gear oil bottle usually has a cone-shaped squirter cap. If you attach about 2 feet of vacuum or fuel line that fits on the cap, it makes it much easier to get the oil into the differential.

I have a question for everyone here. Do we all agree that the leak is coming from the differential cover? I’ve personally never seen a differential leak from the top, but that could just be my experience. I was actually wondering if it might be coming from the brake distribution block above, which would be more concerning.

Just keep it topped off with the right fluid until you can fix it

This post really makes me see how common diff leaks are, and most people just brush it off.

It definitely makes me feel a lot better about the leaky diff on my Grand Marquis.

Mine has been like that for a year already

Just resealed mine. Was still at operating levels after 5 years.

This thread came at the perfect time and is really reassuring.

I just noticed mine looks similar and was quite concerned, even thinking about bringing it to the shop.

It’s really simple to reseal when you have the opportunity, but it also won’t fail anytime soon.