I changed my diff fluid, front and rear. I realized I left the little o-ring off of the filler plug for the rear diff, so I went to take the plug off again.

As I tried, it immediately stripped the edges. I've tried everything I can to get it off, but the plastic just eventually rounds or chips off and makes the job even harder.

I'm strongly considering just leaving the plug in there as it sits.

But here's my question: how tight of a seal does the rear diff require for the filler plug? The plastic plug itself is obviously on there somewhat tight, but I'm worried that it doesn't have that O-ring in there to seal it.

 

Also: I don't go off-road or submerge the diff in the water, so I wouldn't need to access the diff fluid again for a long time, especially since this car isn't driven often.

I just want to make sure that when the oil gets hot as the car is driven, it won't start seaping out of that plug, without the o-ring there.

 

I wouldnt worry about it just drive it around then take a look for any leaks. You should be fine.

 

It would probably be ok to drive it until you get a brass plug from Rovahfarm. But I wouldn't put it off.

 

Those plastic plugs are junk, buy a pair of new metal ones, all of the Rover supply web sites sell them, the DI and DII use the same plugs so you can order a pair of DI diff plugs if you want to.
Then you can tear apart that stupid plastic plug to get it out, throw it away and use a man's style diff plug.

 

Well I guess that's the problem: how do I get the old one out? It's entirely rounded now, and the little dimple in the middle is now a circle, too, since I tried to get it out that way.

Whoever had the idea to use plastic ones here should be forced to come to my house and get this stupid thing out.

 

You can use any method you want to get it out, needle nose pliers, drill a hole in it and thread in a screw or bolt.
Drill out the center and then bend whats left to get it away from the threads on the diff side...you are not going to reuse it so destroying it is your only option.

 

Use a heat gun to melt or soften it and then use pliers to pull it out. Piece of cake, if you have a heat gun.

 

Man good thinking!!!
A propane torch would work too, just wave it over the plug, just enough heat to soften the plastic like "0304" said.

 

drill two holes, and poke in needle nose pliers, even if you have to turn them with a screw driver as a lever.