new fluids in used car?
Thread Starter
Staging Lane
Joined: Feb 2004
Posts: 65
Likes: 0
From: alabama
new fluids in used car? i just got a used 2000 Trans Am M6 (50k miles) and i want to put all new fluids in so that i know exactly what it's running with... what's the best stuff to use? would flushing any of the old fluids be necessary? i don't know if it was running synthetics previously...
Joined: Nov 2001
Posts: 34,632
Likes: 2,558
From: Schiller Park, ILL Member: #317
Well your oil choices are basically endless. There are a few that many people here swear by, like German Castrol, Mobil 1, Amsoil, Royal Purple, etc. Best bet would be to do a search on that to determine which one you feel best about. Personally, I'm using Mobil 1.
As for trans fluid, not sure what the M6 people like to use. The T56 trans is not my specialty. I'm a 4L60E type of guy.
Rear end fluid; since you have a 2000 I'd use a 75W90 synthetic fluid and throw in the GM additive as directed by the GM service manual.
Coolant; stick with Dexcool, and get the system flushed since it's probably been in there for the last 6 years. What I do is to drain and refill mine every spring, but that only replaces about half the coolant (I get about 1.5 gallons out of the 3+ gallon system). I think that's plenty so long as you're doing it every year, but after 6 years and 50K miles I'd say to fully flush it at least for the first time.
As for trans fluid, not sure what the M6 people like to use. The T56 trans is not my specialty. I'm a 4L60E type of guy.
Rear end fluid; since you have a 2000 I'd use a 75W90 synthetic fluid and throw in the GM additive as directed by the GM service manual.
Coolant; stick with Dexcool, and get the system flushed since it's probably been in there for the last 6 years. What I do is to drain and refill mine every spring, but that only replaces about half the coolant (I get about 1.5 gallons out of the 3+ gallon system). I think that's plenty so long as you're doing it every year, but after 6 years and 50K miles I'd say to fully flush it at least for the first time.
Stick with GM fluid for the M6. I know there is a reason you can not use Synthetic in an M6. Something to do with it being corrosive to something in the tranny.
I use Mobli 1 5W30, Dexcool, Rear end is Royal purple w/ Gm additive. I did not change power steering or brake fluid.
I use Mobli 1 5W30, Dexcool, Rear end is Royal purple w/ Gm additive. I did not change power steering or brake fluid.
Congrats again on the new car, Amanda. 
I use Mobil 1 5w-30, dexcool with additive (similar to water wetter), standard ATF in the T56 and JT-7 non-synthetic in the rear diff. If you take your car up to Walker's, he has a coolant flushing machine he can hook up to your car to remove the old fluid, clean the system and add new fluid. It's a lot neater than pulling the block plugs, but it will run you about $70.
I use Mobil 1 5w-30, dexcool with additive (similar to water wetter), standard ATF in the T56 and JT-7 non-synthetic in the rear diff. If you take your car up to Walker's, he has a coolant flushing machine he can hook up to your car to remove the old fluid, clean the system and add new fluid. It's a lot neater than pulling the block plugs, but it will run you about $70.
TECH Addict
Joined: Nov 2001
Posts: 2,003
Likes: 0
From: Live Oak, FL - in the woods where the creatures lurk.
I'm pretty much with RPM here.
Dunno 'bout the M6 too much.
Oil change, differential oil change, flush/refill
coolant goes without argument.
I'm not **** about frequent oil changes with
the Mobil 1 engine oil, but my 10 bolt and A4 I service
about every 25K miles. Still running stock A4
& 10 bolt (see sig)
Dunno 'bout the M6 too much.
Oil change, differential oil change, flush/refill
coolant goes without argument.
I'm not **** about frequent oil changes with
the Mobil 1 engine oil, but my 10 bolt and A4 I service
about every 25K miles. Still running stock A4
& 10 bolt (see sig)
You should not use synthetic in the 2000 M6, stick with Dexron III.
For coolant, stick with Dexcool, no other choice.
I used Royal Purple syn for the rear, does not require additiive.
Now for the hard part, the oil. Personally, I like Mobil 1 5W-40, should use M1 anything -30, its too thin. Search through posts, make you own decision.
Good luck with the car, you will love it.
For coolant, stick with Dexcool, no other choice.
I used Royal Purple syn for the rear, does not require additiive.
Now for the hard part, the oil. Personally, I like Mobil 1 5W-40, should use M1 anything -30, its too thin. Search through posts, make you own decision.
Good luck with the car, you will love it.
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
12 Second Club
Joined: Sep 2005
Posts: 354
Likes: 0
From: Springfield, Missouri
Originally Posted by nikon1999
i definitely agree with everyone on the oil/getting antifreeze flushed. In terms of the m6 tranny though i hear the synchromesh fluids make a big difference 
Originally Posted by waiting2bl33d
the m6 is a dexron mercon III mobil 1 makes a synthetic dexron III that i used and i used the mobil 1 75w-90 synthetic w/ GM additive. my camaro never has shifted driven better after the change and im right at 60000
Originally Posted by waiting2bl33d
very interesting. do they take ATF or do they use gear lube in the eariler models.
I had put M1 synthetic ATF in my 00' M6 about 4K miles ago. The shifting was getting harder. I dumped the M1 and put in regular Dexron III and it shifts great again.
12 Second Club
Joined: Sep 2005
Posts: 354
Likes: 0
From: Springfield, Missouri
Originally Posted by 2000 TAWS6
I beleive that all the m6's were specified as Dexron III, but the later ones were okay with synthetic. Therer is a thread somewhere on here that discusses that.
I had put M1 synthetic ATF in my 00' M6 about 4K miles ago. The shifting was getting harder. I dumped the M1 and put in regular Dexron III and it shifts great again.
I had put M1 synthetic ATF in my 00' M6 about 4K miles ago. The shifting was getting harder. I dumped the M1 and put in regular Dexron III and it shifts great again.
Originally Posted by waiting2bl33d
yes i think i found the thread and read it. very interesting. i have a 02 so i guess im good w/ it but i just figured i'd give my .02 but thanks for the info now im more informed
This place is kind of like "The Collective", we're here to help each other by sharing our knowledge.