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Rear End Fluid Change

M

Ms Kiss

Guest
Has anyone ever installed a drain plug for the differential? Or, know of an easy way to change the fluid without tearing it all apart?

Barbie
 
Joined
Nov 4, 2000
Messages
946
Location
Scottsville, Kentucky
Corvette
08 Jetstream Blue Z51 coupe
differential oil change

Barbie,

I don't of anyone who has installed a drain plug in a differential. Even if you do, you usually have to remove the cover to install. At least thats the way it works when installing a drain plug in a transmission pan. Removing the diff cover is no big deal. Usually the gasket is a thin application of blue silicone. Remove the bolts except one or two on top which you want to leave backed out at least a 1/2". Gently pry the cover loose, use care not to bend it by working around the circumference. Clean all the old silcone off both faces, wipe out any debris and sludge with a lint free rag. Apply a thin bead of silicone and re-install the cover. Don't over tighten the bolts or you will squeeze out the silicone. Good luck!!

Dale
 

trrgod

Well-known member
Joined
Feb 24, 2001
Messages
92
Location
Santa Monica CA
Corvette
1989 Black Coupe 6 sp
This is how I changed my rear end fluid.
Open fill hole with proper allen wrence.
Use a suction device(my buddie's shop has one that hooks up to his air supply, I've heard that you can buy a hand pump type at auto supply stores). Make sure the tube is as far down into case as possible.
Suck out all fluid.
Fill with oil and posi fluid.
You're done.
Why Corvette decided not to put in a drain plug is hard to understand.
 

vigman

Motor head!!!!
Joined
Feb 13, 2001
Messages
3,471
Location
Valencia, CA,USA
Corvette
88 Convert ( SOLD ) /1973 coupe 4 speed/1964 Vert!
Fluids

I did the same thing as trrgod.... anything else is a hassel!
Mike
 

Ken

Gone but not forgotten
Joined
Jan 30, 2001
Messages
8,236
Location
Hermosa Beach, CA
Corvette
1987 Z51 Silver Coupe
drain plug...

I'll have to go to the garage later to find it, but I'm sure I saw an article not too long ago that described the installation of a drain plug in the third member of Corvettes.

Remind me if I don't get back to you in a reasonable amount of time. ;)

Ken
 
M

Ms Kiss

Guest
The responses are appreciated. But what about the metal shavings? I am sure prior owners dumped the clutch once or twice. I plan on keeping this car and figured instead of tearing the unit apart why can't I drill a hole, tap it, irrigate it, use a magnet pen for the shavings, one more flush and fill, and throw a plug in. And, do that anually. Always thought that was part of regular maintanance. Estimates I got from GM dealerships just for a fluid change, were obscene.
Recommendations are very welcomed.

Barbie
 

Ken

Gone but not forgotten
Joined
Jan 30, 2001
Messages
8,236
Location
Hermosa Beach, CA
Corvette
1987 Z51 Silver Coupe
That's it!

Ms Kiss said:
...why can't I drill a hole, tap it, irrigate it, use a magnet pen for the shavings, one more flush and fill, and throw a plug in.

Barbie, I can't find the article and I went back thru a years worth of Corvette Fever and Vette Magazine! I do believe that is how it was done. Sorry I can't be of any more help, but I'm sure if ya took yer time and measured everything twice, there shouldn't be a problem with your idea. ;)

I did find an unrelated article that I was looking for; "Project: Lazarus" - vigmans story sounded familiar. :L

Ken
 
8

84c4

Guest
Barbie,

Ken was looking for the November 1998 issue of Corvette Fever, page 36. There is an article on installing a drain plug.

Contact the Corvette Clinic in Sanford, FL at 407-323-7804. They sell the kit that includes a template for where to drill the hole, drill bit with stop on it so you don't drill to far and a tap.

When you drill the hole the oil will keep the filings from going into the diff. A magnet will only collect material from gear wear since the housing is aluminum. Use Mineral spirits to flush with, solvent evaporates to quick and leaves metal behind.

One more thing, take a short drive to warm up the oil, but let the exhaust cool down, the oil will still be warm.

Have fun :)

Dave
 

Ken

Gone but not forgotten
Joined
Jan 30, 2001
Messages
8,236
Location
Hermosa Beach, CA
Corvette
1987 Z51 Silver Coupe
84c4 said:
...November 1998???

Man, I must be getting old. I could have sworn that I read that just recently! At least within the past year.
Oh well, at least you finally got the real dope Barbie. See, I wasn't crazy after all. ;)

Thanks Dave

Ken
 

trrgod

Well-known member
Joined
Feb 24, 2001
Messages
92
Location
Santa Monica CA
Corvette
1989 Black Coupe 6 sp
84c4- Have you actually put the drain plug in using this kit? I also have reservations on getting all the shavings out of it.
Barbie-any compatent mechanic can drain and fill. This should not be very costly. Certainly no more than 1/2 hour labor. Be sure to get the posi stuff from the dealer to give to the mech. to put in also with the new oil. You should not have to change rear oil every year unless you put a lot of miles on the car. Whoever does it must have a pump to put in oil because there is no room to tilt the oil bottles high enough. You can buy one of the pumps cheap at almost any car parts place.
 
8

84c4

Guest
trrgod,

I have not done it to a Corvette, but I have done it to several other applications where aluminum housings are involved. You don't get metal shavings like you do with steel, the aluminum is soft and the drill flutes pull it out, plus the warm oil is flowing outward washing everything down your arm. I feel it is a better way than trying to suck it out. The stuff you need to get out of the rear end has settled to the bottom. It has to be washed out to do it right.

Just my 2cents

Dave
 
M

Ms Kiss

Guest
Exactly what I was hopeing for!

Thanks guys!! I thought siphoning wouldn't get all the harmfull deposits, and I am surprised more people haven't persued this.
Is this something I should be overly concerned about? I'd rather maintain it then have to fix it. And as far as mechanics go, boy, that's a hole other story.

Barbie
 

Jack

Well-known member
Joined
Dec 27, 2000
Messages
1,825
Location
Florence, SC (Timmonsville SC)
Corvette
71 War Bonnet Yellow VERT 71 BH Blue CPE (SOLD)
drain plug kit at Eckler's

Barbie:
Judging from your 6-speed logo, I'm assuming your pride and joy may be a C4 or C5. If it's an '84-'96, Eckler's latest catalog # 131 p 152 has a differential drain plug kit # 37626 at $70...kit has long drill w/stop, tap and plug...and instructions. I've seen similar kits at other vette houses. I second the warmed oil and mineral spirits. I do not have personal experience tapping vette diffs. Unfortunately, us C3 folk are apparently stuck using the turkey-baster or oyster-shuck methods. Good luck & let us know how it unfolds.
Jack
'71 cpe
 
M

Ms Kiss

Guest
Hi Jack

Well low and behold, how right you are. I am going to try the kit. Just when you think you have bought everything possible from Ecklers, Mad, CC, Zip etc., there is always something else isn't there? No wonder I am on a first name basis with the UPS delivery guys. :L
Thanks again.

Barbie
 
B

BubbleHead

Guest
Barbie,

The diff plug is not a bad way to do things, BUT it's better to pull the cover and do a quick check on your gears and bearings. I do this on my Jeeps constantly. Both of them see rivers and deep mud pits. My case is probably a worst case scenario, but I always feel better to be able to check the wear pattern on the ring gear, along with the over all condition of my diffs.

Just something to think about.

Tim
 
M

Ms Kiss

Guest
Hi Tim

?????? Isn't that like taking the oil pan off to do an oil change?????? Don't think I want to have to do that annually. :eek:

Barbie
 

vettenuts

Well-known member
Joined
Nov 13, 2000
Messages
123
Location
Wakefield, RI
Corvette
2002 Mag Red Convertible
I am in the no drain plug camp. I don't feel confortable drilling without ensuring no metal shavings. I have the miti-vac with fluid transfer kit. Eastwood sells this amongst others. I can change the fluid in about 20 minutes and I take my time. Not sure why you want an annual change unless you are racking up the miles. With a good synthetic (I use Redline) you should be able to go many miles between changes. 30K is a reasonable mileage unless the car has severe service (racing, etc.)
 
B

BubbleHead

Guest
Re: Hi Tim

Ms Kiss said:
?????? Isn't that like taking the oil pan off to do an oil change?????? Don't think I want to have to do that annually. :eek:

Barbie

No, you don't have a ring and pinion in the motor :D

Seriously, you make it out to be a hard job and it's not. I can do both axles on my Jeeps in about 45 minutes, taking my time. I like to inspect the ring and pinion for signs of premature wear. You add ten minutes to the job (only one axle). If you are not concerned about the condition of your gears, the drain plug is the way to go, I guess.

I just look at a few more minutes as cheap insurance and piece of mind.
 

vettenuts

Well-known member
Joined
Nov 13, 2000
Messages
123
Location
Wakefield, RI
Corvette
2002 Mag Red Convertible
Re: Re: Hi Tim

BubbleHead said:


Seriously, you make it out to be a hard job and it's not. I can do both axles on my Jeeps in about 45 minutes, taking my time. I like to inspect the ring and pinion for signs of premature wear. You add ten minutes to the job (only one axle). If you are not concerned about the condition of your gears, the drain plug is the way to go, I guess.

I just look at a few more minutes as cheap insurance and piece of mind.

The C4 cover removal requires removal of the cat back exhaust, spare tire carrier, half shafts, tie rods, camber rods, drive shaft, transmission support beam and then full rear differential removal. There is no cover like the Jeep, the cover actually is bolted to the frame just above each rear wheel. Don't think you can do it in 45 minutes. I have done it several times, and my best removal time is 2 hours. Installation is another issue though:D
 

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