2000 Buick Century ATF change?

[JimmyJohns]

Hello folks, happy humpday.

I come do you today looking for some input regarding my mothers vehicle, she owns a 2000 Buick century with just about 85k miles on the dash, bought it about 5 months ago.


I really want to do my best to take care of the car, and a transmission fluid change is on the list, but I'm weary to do so. There is no maintenance history of the fluid and filter being changed, the only thing I know for certain is that transmission lines were done on it about 2 years ago, I know the mechanic who performed the service. Previous owner was an old fella who most likely drove like a grandpa, and my mother drives like a grandma(the car definitely fits her)..

I have attatched a link to an Imgur album contain pictures I took of the fluid on the dipstick, looks like its right on the border of burnt, smells like it's on the border as well, not an an overwheliming smell of burnt ATF but just a hint of it.

Trans dipstick fluid


Here is where my concern is highlighted, under normal driving circumstances, the car shifts fine, nice and smooth. Can't really feel any down shifts, but around 5-10 mph you feel the torque converter unlock I do believe.

I drove it the other day to get a feel for it, and if you really lay on it, 1st to 2nd almost seems like it slips, takes too long to shift in my opinion, doesn't rev high, just takes too long to get into 2nd and go again.

I know these cars transmissions were known to have issues with the accumulator springs, so I'm curious if anyone has had any experience with this and can chime in. I have no problem rebuilding the accumulator with this kit but I'd like to know if anyone has had the same issue before I jump in


If I do perform the service, I will be dropping the pan, changing the filter, rebuilding the accumulator, and reusing the gasket on the pan after I clean it all off,



I'm not sure if that fluid is past the point where it's safe to change it, I'm trying to play it safe here since she needs the car daily for work so I can't really gamble too much with this.


Any input is greatly appreciated and opinions on the fluid and 1st to 2nd shift are strongly encouraged. Anything else that I missed that should be serviced if I do happen to perform this service please share.


Thanks for reading.

 

[JC1]

That fluid doesn't look too bad. Just do a drain and fill. What ATF is specd is the owners manual?

 

[JimmyJohns]

I have not checked yet, but I see some people run valvoline maxlife. I will do my research before deciding what to refill, I just haven't gotten that far yet.

 

[ls1mike]

Use DEX III or DEX VI

This should be the 4T65E. A pan drop with filter is 7 to 8 quarts. (7.4 to be exact)

I believe the transmission holds around 13 quarts.

Consider putting in a Trans Go shift kit. It will make shifts crisper/firmer and will certainly help the 1 to 2 shift.
Should give you some extra clutch life.

 

[JimmyJohns]

Originally Posted By: ls1mike
Use DEX III or DEX VI

This should be the 4T65E. A pan drop with filter is 7 to 8 quarts. (7.4 to be exact)

I believe the transmission holds around 13 quarts.

Consider putting in a Trans Go shift kit. It will make shifts crisper/firmer and will certainly help the 1 to 2 shift.
Should give you some extra clutch life.



That is indeed the correct transmission, just looked it up, Dex III is the recommended but Dex VI is compatible as well evidently. That transgo kit is exactly what I wanted to put in there, not sure if you spotted my link in the orignal comment, but thank you very much for the suggestion. Very reassuring so far.

 

[ls1mike]

I have had 5 4T65Es in my life. The Trans Go works great and is easy peasy!!!

 

[Chris Meutsch]

Let's go Buffalo.

Use the fluid the above posters mention, you will get the best life.

 

[901Memphis]

Factory fill was Dexron 3, the correct fluid is now DexronVI. I run Maxlife in my 2002 century (same transmission) which is a 2 year old rebuild by triple edge and it shifts great. Part of their rebuild includes the shift kit from transgo along with lots of other goodies.

Definitely change the fluid if you can. Definitely install the kit if you can. But be mindful the kit helps preserve intact clutches so if yours are already worn and slipping it won't help much.

Have it scanned for transmission codes, as long as it doesn't have the dreaded max adapt code the clutches are probably okay enough that the kit will help prolong the life.

My original transmission had a lot of miles on it with the previous owner driving all highway and never changing the fluid. I got it changed the fluid and drove it on max adapt for two years (30k+ miles) banging gears and occasionally slipping before I had the money for the new transmission.

They have their quarks but not anymore than others automatics and they tend to run to 150k city miles if you don't a hard part or band which is another somewhat common problem.

Here is a resource from the guy who did my transmission rebuild. He's the expert.


http://www.tripleedgeperformance.com/4T65E-Common-Problems.html

 

[R18Civic]

I highly recommend you do a drain and fill and replace the fluid with Dex VI. It has a much longer service life and the friction modifiers are a 100% improvement over Dex III.

I change mine in my 2009 Buick every 50k and it still has a nice pinkish/red color to the fluid.

 

[JimmyJohns]

Any issues removing the tranny pan bolts? The last thing I want to do is snap one off.

Go slow and easy is the name of the game I know that much, if it gets too hard to turn then screw back in a bit and back off again.

 

[901Memphis]

Originally Posted By: ls1mike
Use DEX III or DEX VI

This should be the 4T65E. A pan drop with filter is 7 to 8 quarts. (7.4 to be exact)

I believe the transmission holds around 13 quarts.

Consider putting in a Trans Go shift kit. It will make shifts crisper/firmer and will certainly help the 1 to 2 shift.
Should give you some extra clutch life.


Keep in mind there is no valid license in place for DexronIII since DexronVI superceded it. Be careful buying cheap mineral based fluids claiming to meet Dex/Merc unless they're from a major brand, but even so DexronVI is a synthetic blend and is better than DexronIII or any mineral Dex/Merc you can get.

All DexronVI carrying the official GM license will perform identical due to the strict requirements on base oils and only one additive package they approved. This means Supertech $4 a quart DexronVI is just as good as the $10+ quart of AC Delco or other name brand Dex6

That being said I prefer Maxlife over DexronVI and consider it a superior fluid.

 

[R18Civic]

Not issues with the tranny bolts. Just make sure they go back in the same spot they came from. When reassembling only snug em up plus 1/4 turn. Manual only calls for 89 in lbs.

 

[3800Series]

It can't hurt really. Typically it's a good idea to do it as most transmission failure is do to overheating and a majority of the time it can be linked to poor maintance.

I agree with dropping the pan and replacing the filter. It's not that hard to do at all if you already have ramps. You can get a gasket and filter kit from almost any auto parts store. Take the gasket out a day in advance and lay it out flat and put a few flat objects on top of it to flatten it out. That will make it a lot easier. You can also get some RTV gasket maker to help hold the gasket in place.

 

[zzyzzx]

That car has a transmission dipstick?

 

[R18Civic]

Originally Posted By: 3800Series
It can't hurt really. Typically it's a good idea to do it as most transmission failure is do to overheating and a majority of the time it can be linked to poor maintance.

I agree with dropping the pan and replacing the filter. It's not that hard to do at all if you already have ramps. You can get a gasket and filter kit from almost any auto parts store. Take the gasket out a day in advance and lay it out flat and put a few flat objects on top of it to flatten it out. That will make it a lot easier. You can also get some RTV gasket maker to help hold the gasket in place.


I know with the 4t65e the gasket has metal ribs for reinforcement and can be re-used. The parts store replacement gaskets are typically paper, cork, or a thin rubber seal with holes for the bolts and don't look like they last very long.

 

[BigD1]

Are you guys using blue thread locker on the transmission pan bolts? Don't have the book on that transmission, but I do know some GM tans require some of the bolts to have thread locker.

That fluid looks a lot better than what came out of my 92 Olds. It was brown, but it's normal as long as it does not smell burnt.

 

[92saturnsl2]

The 4T65E has always had sort of mushy slow shifts, IMO. It's a Buick Century, so they're certainly not going for performance. I've drive a handful and I like them well enough though.

I installed the Transgo shift kit into my '00 Bonneville, but it had the 4T65E-HD, the heavy duty one used on the supercharged 3800's. It made a big difference in shift feel, but if you're used to slow, mushy shifts, it can feel strange at first (a bit abrupt.)

I haven't always coveted the idea of using the lower viscosity Dex-VI in older, high-mile transmissions that originally used Dex III. I did however, switch to Dex VI in my Bonneville at around 130k with no noticeable ill effects. When I traded it in at 175k miles, it felt like the transmission needed a rebuild. The shift feel was pretty sloppy by that time, and it had a weird torque converter lockup issue, where the TC lockup wouldn't disengage at times. Tranny issues at 175k was probably not that unusual for a 4T65E of that vintage, but I still wonder if I could have eeked out a few thousand more miles of life by using an ATF with viscosity closer to the orig. Dex III. If I need a good synthetic ATF for older vehicles, I use https://www.amazon.com/Mag-Synthetic-Multi-Vehicle-Automatic-Transmission/dp/B0051ZHC3C nowadays. The Dex VI is too low a viscosity for an older auto trans in my opinion, unless it spec'd a low viscosity fluid (Dex VI, Mercon LV, Honda DW-1, etc.) from the factory. For those vehicles that do spec a LV fluid, I like to use https://www.amazon.com/Mag-64092-6PK-Multi-Vehicle-Viscosity-Transmission/dp/B00DE7LVSG which is a synthetic Dex VI clone. I've had zero transmission faliures or issues in many years, using these two fluids.

Regarding the fluid color / trans condition: The color of fluid on the disptick, to me, says old/used fluid, but still looks serviceable. Used & abused fluid will lose it's pink/red hue and begin turn brown (burnt) or greyish if there's suspended particles (wear metals, clutch material, etc.) in it. I wouldn't hesitate to change it out and get fresh fluid and filter in there.

 

[slacktide_bitog]

Dorman makes a transmission pan for your car, so you won't have to drop the pan again, making future ATF changes much easier

 

[Trav]

This is a very easy unit to do a line off exchange on, you are looking for the Accumulator shift kit not an actual shift kit that requires removing the valve body, that is a semi difficult job on this unit in the car. I suggest you get the Sonnax line clamp when you do the accumulator.
I run Amsoil ATF not the ATL in all these units, One I have has a GMR Torsen and GMR 1" chain living behind a high output engine for some years now, the fluid holds up nicely.

https://www.amazon.com/Sonnax-84532-01K-KIT-RETAINER-DIFF/dp/B00DP5Z7E6

 

[JimmyJohns]

Yes the accumulator is what I planned on rebuilding, rock auto has it listed as a shift improvement kit manufactured by transgo. May I ask what the job of that line clamp is?