ATF recommendation for 2002 buick century

[901Memphis]

Looking for a fluid recommendation for a 2002 buick century with the 3.1 v6. Have heard of using OEM fluid, maxlife, and have considered Mobil 1. Any thoughts?

Also does anyone know the pan size and total system capacity on these trannys?

 

[JohnnyZ52]

My 2002 car uses Maxlife and performs very well. I don't know how much difference the fluid actually makes, I think the condition of the transmission when it's changed makes more of a difference. Have heard good things about a Lucas additive, though.

 

[umungus1122]

I'd go Maxlife or Supertech Dex 6 with Lubeguard Red.

 

[sciphi]

Should be a 4T65 with a capacity of 12 quarts of ATF. Pan size is about 5-6 quarts. Maxlife does very well in those older GM transmissions.

 

[JHZR2]

Id run straight Dexron VI. No need for anything else, no additives, etc.

 

[WishIhadatruck]

I have a 2001 Grand Prix with the same trans.

Here is my history and what I've done.
Bought new.
30k I did a pan drop and filter change with M1 Dex IIIh
60k I did a pan drop and filter change with M1 Dex IIIh
90k I did a UOA, it looked good. Flushed with Dex VI after the pan drop.
120k I did a pan drop and filter change with Dex VI Installed a shift kit to fix occasional hard shifting issue.
150k I did a pan drop and filter change with Dex VI
180k I did a UOA, looked even better than at 90k. I then flushed it with Redline D4 after the pan drop.
Around this time I was getting erratic shifting and torque converter lock-up. It was not better with the D4 and eventually got worse. Changed out the MAF and all is good now with 193k miles.

You get about 8 quarts of fluid out with a pan drop and filter change, a pretty large % of the fluid capacity. I honestly think that 30k interval pan drops and filter changes are adequate. I like to experiment a little which is why I have D4 in there now but I'd just recommend Dex VI of any brand.

My previous car was an older GP a 4T60E (vs a 4T65E) and I did 30k pan drops and filter changes its entire life (212k miles and 13 years when I got rid of it) and all I ever used was name brand Dex III, nothing synthetic. It was a flawless trans the entire time.

 

[901Memphis]

So if i went with maxlife i would just get the DEX/MERC or does the DEX 6 make any difference?

 

[dnewton3]

OCI plan?

Any normal interval would be easily serviced by a good house brand Dex/Merc alternative. I believe DEX III was the FF.

 

[Whitewolf]

Originally Posted By: 901Memphis
So if i went with maxlife i would just get the DEX/MERC or does the DEX 6 make any difference?


The difference is that some so called 'DEX MERC' product could be literally anything, however a genuine DEXRON branded product is by definition tested, approved and controlled.

 

[901Memphis]

So would Dextron VI be a good choice then? Also is it bad to mix DEX/MERC with Dextron 6?

I saw a couple brands available, Valvoline, Pennzoil and Castrol both make a DEX VI. Are they equal?

 

[Whitewolf]

Get rid of the DEX/MERC and replace it with DEXRON-VI.

 

[Whitewolf]

If they are real DEXRON-VI then they are equal. Look for the licence number on the label. That is vital.

 

[901Memphis]

What does the license number look like?

 

[Whitewolf]

It's a J-followed by five digits.

 

[Whitewolf]

If you go to www.gmdexron.com you can see an example.

 

[Whitewolf]

And I should add get a link to the approved fluids list.

 

[901Memphis]

After getting a better look at the condition of the fluid i think i might put some DEX/MERC in there to get all the old junk out then switch to DEX 6.

The old fluid looks pretty bad though. I'd hate to send it in for UOA. Could possibly be almost 100k miles on this fluid.

 

[johnsmellsalot]

Dexron VI is better than Dexron III. It is backwards compatible too. Don't use additives.

 

[901Memphis]

The fluid looks like fresh motor oil. Light brown but not burnt smelling. I think its been in for 100k. Going to need to get it out soon.

 

[martinq]

Originally Posted By: johnsmellsalot
Dexron VI is better than Dexron III. It is backwards compatible too. Don't use additives.

Yes, yes and yes.

Originally Posted By: 901Memphis
I think its been in for 100k. Going to need to get it out soon.

YES!