Rear end drain plug stuck, could i fill it through the vent?

[DarkknightGT]

So when changing my differential gasket I made the discovery in place of my 8.8 was a 7.5 rear differential out of a 98 v6 mustang. Car is a daily so while I was a bit peeved I got the wrong gasket, I order another and snagged it. Long story short I tried to take the fill plug off and ended up stripping it. I know I'll need to get it off at some point, but I have been doing a bit of reading that you can fill it through the vent tube on the axle because it goes to the differential. Is this true? I'll still get the fill plug off I just wanna see if I can do that just to get 2 quarts of gear oil in the 7.5 so I can drive the thing again. Any help is appreciated. Thanks for looking

 

[cobrajeff96]

Yes, you can. It'll just take you a long time. But be careful, you can overfill it this way especially since the fill plug can't be opened until you fix it.

My advice, buy a steel hex spacer tube, weld it to the fill plug (carefully). After a few minutes, take a propane torch to the fill plug as best you can for about 20 seconds, then unwind it.

 

[DarkknightGT]

Yes, you can. It'll just take you a long time. But be careful, you can overfill it this way especially since the fill plug can't be opened until you fix it.

My advice, buy a steel hex spacer tube, weld it to the fill plug (carefully). After a few minutes, take a propane torch to the fill plug as best you can for about 20 seconds, then unwind it.

Sweet! I have the car already all buttoned up, I did it backwards, should have seen about taking the fill plug off FIRST instead of the other way around. First time jitters I guess lol, but I will definitely keep that in mind. I work at a parts store so I'm gonna see about getting a replacement and just using an extractor. Unfortunately don't have access to a welder at the moment. But that isn't a very bad idea.

 

[DarkknightGT]

Yes, you can. It'll just take you a long time. But be careful, you can overfill it this way especially since the fill plug can't be opened until you fix it.

My advice, buy a steel hex spacer tube, weld it to the fill plug (carefully). After a few minutes, take a propane torch to the fill plug as best you can for about 20 seconds, then unwind it.

Also, would 2 quarts of 80w90 be enough? It's an open diff so no trac-loc (unfortunately) don't wanna overfill this thing

 

[shovel]

I've heard tales of people just putting ziploc bags full of oil into axles when they couldn't fill through the fill plug. Never done it myself but if you need ideas there's one.

 

[cobrajeff96]

It's really not that big of a deal if you overfill. The excess usually just pukes out of the vent as vaporized oil. But then yea it kind of gunks up your rear bumper and tail lights until you wash it all off. Been a long time since I ran with a SRA but I seem to remember it taking more than just a couple quarts.

 

[RAU03MACH]

id be looking for an 8.8 rear end

 

[cobrajeff96]

I do have one up for grabs, but alas it is in Germany at this time.

 

[DarkknightGT]

It's really not that big of a deal if you overfill. The excess usually just pukes out of the vent as vaporized oil. But then yea it kind of gunks up your rear bumper and tail lights until you wash it all off. Been a long time since I ran with a SRA but I seem to remember it taking more than just a couple quarts.

True that. Tried a bolt extractor and unfortunately didn't work. I'm at a loss right now

 

[cobrajeff96]

Clean it with brake clean or acetone, take it to a shop and have them (carefully) weld a nut onto the plug but not to the housing. I think it'd be difficult for a weld to actually stick to that iron axle but you never know. Or weld a bolt to the plug and that might work better actually, the hex head facing out of course. That should stand it off enough for you to get a socket or wrench on it and twist it right off. It's probably a 3/8 npt plug. You can buy those anywhere online.

 

[Bronco2Fan]

Why can't you just get another diff cover? Especially if you work at a parts store. Just asking.

 

[cobrajeff96]

The fill plug for an SRA is actually on the driver front of the axle and is the true fill line. If you fill it up to the fill plug on most (or maybe all) aftermarket covers, that's a guaranteed overfill and gear oil vapor will spew everywhere.

 

[weendoggy]

The fill plug for an SRA is actually on the driver front of the axle and is the true fill line. If you fill it up to the fill plug on most (or maybe all) aftermarket covers, that's a guaranteed overfill and gear oil vapor will spew everywhere.

There are several covers that have a fill plug in the correct position, plus a drain. You just have to search for them. Summit Racing has at least two to choose from.

 

[Mustang5L5]

The bolt on my 8.8 stripped out a long time ago. Ended up just buying an aftermarket diff cover with a drain and fill port on the cover. That alone was worth the cost of admission as it's just a much easier time filling from the front.

Also, i like using the Lube Locker gaskets. No more RTV. Install them dry and i've had them on and off a few times without leaks. Really nice gasket. I have them on both my Mustangs.

 

[cobrajeff96]

If the OP has OEM cover there is no fill port on it.

 

[weendoggy]

If the OP has OEM cover there is no fill port on it.

I believe this is true, but, the OP already drained the oil and then found the stripped plug. So, all they need to do is replace the cover (that has a fill port) and then fill it.