Harbor Freight or an auto-parts store will have a cheap fluid tranfer pump to remove the fluid (take your time and don't spill--used gear oil is nasty & it stinks). You want to move the hose around and get as much of the old oil out as you can.
For refilling, I bought 2 quarts of Lucas heavy duty 85-140 gear oil, and two bottles of trans-x posi-trac limited slip additive at Advance Auto. A full bottle of each, followed by a half bottle of the trans-x, then top off with the gear oil.

 

I just bought one of these to bleed my brakes, it should also work to siphon the differential.
http://cgi.ebay.com/ebaymotors/Mityv...Q5fAccessories

Put the additive in first, if not you may not leave room and have to take oil back out. I used 80w gear lube from advance an GM additive.

BTW, someone told me the additive was originally made from whale oil,
don't know if that's true.

 

hey guys i'm getting up bright and early to change the fluid but i have a problem. i have a haynes manual and a GM shop manual but neither specify what viscosity fluid to use and what the capacity's are?
anyone know the spec's
ps. or i cant find them in the manual(which is a possibility

thnx
J

 

Both psycho dad and I have suggested weights...?

It isn't necessary to know the capacity, because you fill the diff until fluid runs out the fill hole. You just have to make sure you get the additive in before its full. Couple of posters have mentioned this as well.

 

90 bucks a hour

whoa...................

 

you'll need 2 bottles, there'll be some left over.
Godd luck.

 

sorry about the redundant posts. I'm just a little nervous as this foray into working with the diff is new for me. The grinding noise that I'm trying to address is taxing my mechanical abilities. lol
It shouldn't be because while i'm not a mechanic I've accomplished more involved tasks before.
I'd also like to THANK all the forum members on this site for the advice and suggestions. this is gonna sound cheesy but on more than one occasion this site has kept me driving my vete instead of saving to pay the mechanic. Wish I could for the advice

PS. eta on diff fluid change t-4hours lol

Thnx
J

 

Mission failure!
Well finished changing diff fluids wasn't so bad after all.
BUT, problem still there.
Maybe it's one of the u joints? Anyways at least the diff is done for a while. Guess the vette will go to the Dr. After all.
On the upside I guess the "other women" is always expensive. LOL

 

It will not make a difference that your not a mechanic, I have met plenty of mechanics that should not be mechanics. With that said approach it systematically. First let me try and figure out what you are hearing or feeling. When this issue happens, are going straight or any turn no matter how slight. Usually if you have a clutch chatter you will feel it in the seat of your pants and it will feel as if something is very wrong and the back end is about to come out of the car. Normally you use two bottles of GM grease and one bottle of additive. Some cars will require two bottles of additive. Usually a chatter will happen when the car has not been driven instead of 25-30 min later though.
So if those symptoms are not what you have you NEED to check the wheel bearings. Start by jacking up the car safely and use a jack stand. You want to grab the wheel at the 12 and 6 o'clock position and try and move it up and down. Now you dont want to move the top in and out but up and down. Moving it in and out will not tell you if the wheel bearing is bad, but will let you know if you have trailing arm movement or the stub axle is bad. Move the wheel up and down will check for bearing play, if you feel anything then it is time to pay to have it checked or just be on the safe side and replace it.
This is a good time to get a good Corvette mechanic involved, check with your local Corvette Club and find out who is good and they recommend. This will actually save you money in the long run and get it fixed. While you may find a "cheaper" alternative for a experienced Corvette mechanic, in the end it will cost you more if it is not done correctly. Don't be discouraged though, these are old cars and sometimes they just need a little more TLC, but in the end it is well worth it when you get to go cruising in it. If you have questions please don't hesitate to PM and ask me.
Thanks
Justin

 

thnx jabbott

pm sent

 

pm replied.

 

okay getting up early to try last available option to me at my skill level.
I'm gonna try lubing the half shaft u-joints
I know I'm gonna need to by a lube gun but i dont know what type of gun or lube to use?
suggestions? options from autozone/advance or type. and remember your talking to a layman here


thnx in advance
J

 

also as a reply to earlier post i checked the movement of the wheels while the car was jacked up and i dint notice any unusual play in the up/down or side to side movements.
neighbor suggested there might be trash in the caliper causing the piston to stay out. any one with a suggestion on how i can rule that out without taking the caliper apart

 

Just curious. When you say all parking brake hardware removed are you also saying the little brake shoes inside the rotors are also removed? Sure sounds like the shoes rattling around or broken off parts rattling around.

How do the teeth on the spindle look?

Jim

 

well here's an update

checked the u-joints they seem fine. So ran by local vette mechanic and he did a quick once over and said he doesn't think its u-joints or bearings
his advice was to try a few things first and if that didn't work set up a appointment
1. bevel the brake pads on the corner edges
2. try adding the friction modifier to diff anyways(also previously suggested by forum members)
and if those don't work bring it back.
another thanks to all the forum members who've helped up to now
I will let you know what turns out

ps. jdp6000 thnx and there is Nothing left regarding parking brakes

J

 

still sounds like a wheel bearing to me.

 

Start cheap. Agree with changing the fluid and ensure additive is added.

 

Another possible problem is that your flexible (rubber) brake lines [at each wheel] are degrading. When that happens, you apply the brakes and that flex line can actually retain pressure on the caliper--even though you've released the brake pedal. The small passage in the flex line interior gets plugged up with the degrading (and swelling) rubber so that all the pressure can't release.

The end result is that one or more calipers can be partially applied and cause some dragging on those wheels. After driving it for a bit, stop and walk around the car feeling each wheel (not tire) for any heat buildup. If you find any that are hotter than the others, that's likely your problem. If so, that's a dangerous condition that could end with a brake fire....followed by a CAR fire! And, if you replace one of them, replace them all!!!

I hope that's not your problem, but be certain that it is not. P.S. This happened to me before I knew that was even possible...and caught it just in time. The last ride before I discovered it left the right/rear wheel smokin' hot.

 

i know everyone is talking posi and u- joints, but i would consider the wheel bearing. this is exactly like the symptoms i had with a bad wheel bearing. it would only start grinding ( not squeal ) when driven about 1/2 hour. this will be expensive but worth the headache and safety factor.good luck.

 

Sometimes it takes 100+ miles for the new additive and fluid to work.