Im having my mechanic give me a drain plug for the rear diff.

[SwaveDave]

Hes going to give me a 1/8" npt plug in the housing of the rearend. Will make changing diff. fluid a snap. Hes going to drill and tap the hole with the fluid still in the case so the little metal shavings come out with the fluid. Has anyone else done this ?

 

[ChuckG]

Why? I don't change my rear diff grease that often....maybe once every 5 years or so. I have a "slurp" gun...looks like a big syringe with a vinyl hose on the end. Easy to suck it out. Chuck

 

[C3forME]

I agree with Chuck.

 

[SwaveDave]

I want it ALL to come out ; i like the ease of the drain plug method , and i change the diff. fluid every other year along with the manual trans. fluid. To each his own.

Dave

 

[Shawn's 78]

For me, I use a "vacuum canister" that is used to change the oil in my (late) boat. You suck all the air out of the storage can, insert the long plastic tube into the oil you want extracted and release the valve. In about 5 minutes it sucks up the oil and is neatly stored in the can for a quick and clean disposal.
You can get one of these cans at any marine supply store - $40.

Shawn

 

[DkBG]

1/8 seems kinda small for draining 90 wt. gear lube . Other than that it seems like a good idea to me . Its hard to get everything out with a suckgun . Especially metal shaveings .

 

[MaineShark]

I think I gotta agree with Chuck, as well. The benefits don't add up, compared to the risks. The plug is on the side of the housing for a reason: it is protected from impacts. A plug on the bottom could be hit by a stone, leaving a hole in the diff housing. Unlike the oilpan plug, there is nothing like the oil pressure sender to tell you that you are losing fluid. Well, not until you start hearing that nasty sound, and it's time to rebuild the rear end...

The small amount of old oil that will be left will not have a detrimental effect, especially with your every-year fluid change.

Plus, you are going to leave shavings in the housing: when he drills, the fluid will come out, taking (most of) the drill shavings with it. But then he will have to tap the threads, and the housing will already be empty, so the shavings from tapping the hole will still be there.

Joe

 

[SwaveDave]

My mechanic will use a strong suction device to get the shavings out after tapping it.

An 1/8" hole is fine for draining, so long as you get the fluid good and warm .. and remove the top fill plug when draining out the fluid (so air can get in there).

The drain plug will be protected from road debris, and, it will will be a galvanized metal pipe plug i use.

Dave

 

[JohnZ]

An 1/8" hole is fine for draining, so long as you get the fluid good and warm .. and remove the top fill plug when draining out the fluid (so air can get in there).

Dave

A 1/8" NPT thread is actually 3/8" in diameter; it will drain with no problem.

 

[Dave L.]

Dave - I think it is a great idea,I have considered it myself. For now though,I continue to use my suction gun as the others do.
I also change my gear oil every other year. When and if I ever need to repair the rear gears,I will install the plug at that time.

Dave

 

[Interceptor430]

Dave, I like the idea too and may use that idea on an old Bird I'm building.....I do, however, remember having the rear end oil changed in another old ford of mine at the quick lube. $10 and it was done in 10 minutes. They sucked it out and filled it in that little time....kinda hard to beat that price and time saved.

 

[SwaveDave]

Thanks for the comments.

I like doing as much work on my vette as i can ; i get into it . And , ive had too many people work on it who dont know whats going on...both Jiffy Lube oil changers and so called 'corvette' mechanics. I like doing the maintenance myself ... its a bonding experience !

Regards, Dave

 

[crf311]

either vette or corvette fever just had a article of a kit one can buy. Looked easy. If I can find the article I will post which mag and issue.

 

[SwaveDave]

CRF

Thats where i got the idea from. It was Corvette Fever mag.

Except, they show the drain hole plug going thru the undercarriage support and into the bottom of the diff. housing ; thats about one inch thick of solid metal to go thru !
My mechanic isnt going to do it that way.

I measured the actual diameter of 1/8" plug threads...and it is in fact, 3/8" wide so that will drain just fine.

Dave