Mt 2000 has 65K miles on it and the dealer says the trans. should be serviced ($150.00) I called around and received quotes from $98.00-$179.00!! I told him the book says it doesn't need to be changed (good for life ). I'm not above changing it myself, however I don't have a lift. One of my books says it holds 12 quarts! Is that a misprint? I'm NOT talking about the auto. trans. but the MN6. I find it hard to believe that it holds that much. Am I waisting my time and money? I'd have to buy a pump and the fluid. I did my own brakes a few months ago, and had no problem. Is the fluid change a relativly simple procedure? I'm looking for encouragement here.

 

It's easy. I put Redline in mine when I had the car apart last winter. I bought a hand pump (Like a big handcleaner type pump) for about $5 or so at Autozone. I don't remember the amount of fluid, but I'm sure it's not 12 quarts! You might want to do the rear too. I replaced the plugs with magnetic ones.

 

The dealer replace the rear not too long ago. They couldn't fix the leaking seal on the left side and then it ate a carrier bearing. It was under extended warranty

 

It holds less than 4 qts. If you can do brakes you can easily do this job. I did mine a while back and shifting was improved significantly.

 

That's primarily why I'm changing the fluid. The shifting is getting a little "notchy" especially the 2nd to 3rd shift. The dealer just installed a new shifter a few months ago. The service tech. thought it was a little difficult to shift. I don't know if that was the correct "fix" but it was covered by warranty, so they did it.

 

I've changed my MN6 twice now. First time at about 50,000 miles, I used Mobil 1 Synthetic, better shifting, but after 50,000 miles (at about 100,000 total miles) it started grinding going into 6th gear. I changed to Amsoil ATD and it fixed it.

1997-2000 C5s have paper blocker rings and can only use certain synthetic oils, Amsoil is one of them. Not all people agree on this.

These transmissions are sensitive to dirty fluid, I would recommend changing every 50,000 miles. It is easy, they have a drain and fill plug. You do need a fluid pump ($5-10 at an auto store). It takes less than 4 quarts. Make sure you have the car level when filling (I use 4 ramps).

 

 

Go buy 4 qts of Redline D4 ATF and a hand pump and you're set to go.
The M6 takes 4.1 qts to refill after a complete overhaul and slightly less than 4 qts on a drain and refill. You're going to spend more time jacking it up than you are draining and filling it. It will make a noticable difference in the shifting.

 

Much thanks! It sounds like a straightforward process. I couldn't see spending $100-200 for someone else to do it.

 

Piece of cake!

 

The MN6 holds 3.7 quarts.

Though GM change intervals are really long, they aren't fill for life. My 02 Z06 owner's manual says 100k mile unless you operate in one of these conditions:
- In heavy city traffic where the outside temperature regularly reaches 90F or higher.
- In hilly or mountainous terrain.
- High performance operation.
Uh... it's a Corvette, doesn't that last one apply to all of us?
In these cases, the owner's manual states to use a 50k mile change interval. Personally, I think that is too long.

Check out how Texaco Havoline performed in this test:
AMSOIL vs Havoline ATF Viscosity Testing

It failed the viscosity test at 500 hours. How many miles is that? 25k maybe?

Changing the manual transmission fluid is pretty easy if you have a good jack and some stands. I use Rhino Ramps (about $25 a pop at Walmart). Here is a simple primer:
- Lift car and put up on ramps/stands. Ensure it is level.
- Open fill plug (driver's side about halfway forward and halfway up - where tranny temp probe plugs into tranny)
- Open drain plug (passenger side, bottom rear corner where diff and tranny mate)
- Drain fluid
- Replace drain plug
- Pump in new fluid until it comes out fill plug. You'll need something like this: AMSOIL Hand Pump. You'll need 4 quarts, but the fluid will likely reach the fill hole at about 3.5 quarts.
- Replace fill plug and reconnect tranny temp probe
- Lower car
About an hours work for me, but I've done this more times than I can count.

 

Thanks for the input. It sounds easier than I thought!