98BuickRegalGS

Ok I been doing reading on fluids I read every search result and every google result and I still dont know what to put in.

So Im going to do process of elimination

What are you guys running? How long have you been running it? Did it destroy your transmission?

I want smoother shifts but the paper blocker thing makes me paranoid and I dont want to destroy my transmission putting the wrong stuff in. I would like smoother shifts but If I have to I will put in the stock stuff.

1Sweet66

I've been looking at these threads too for my '99 6 speed. Seems like a lot of talk about it. I'm just looking for a fluid that I can get locally ( Pep Boys, AutoZone.....) that would be a good all around fluid. No raceing fluids just a general use fluid.

I'm up for any suggestions.

71'AirStrike

my 2 cts

around the 99 to 00 years the 'plates'(?) went from paper to Carbon fiber.

If your tranny has been rebuilt by GM any time after 00' it was swapped with Carbon Fiber units.

the thinking is that the Synthetic stuff (royal purple, Amisoil, yadda yadda) will swell the paper plates(?) and shorten the life of the tranny. If you have Carbon Fiber, put in all the Synthetic stuff you want.
I too have a 99' and I used GM Synchro Mesh fluid in the tranny(pricey stuff). used it for 12K miles with no problems so far.

cheers
Chad

lucky131969

I don't auto-x my car, so Dexron non-synthetic was a no brainer(what the service manual calls for). Changed the fluid around 70K miles. Dramatic difference in shifting smoothness, and no more issues getting into 1st gear at a stop.

mcgilles

intersting. I have some issues in 1st at stoplights also. been wanting to swap the fluid but didn't know what to go with. the owner's manual says it never has to be changed! so you just put in the basic Dextron III ATF and saw improvements?

replacement procedure is remove the drain and empty it, then plug the drain and open the fill and pump it in until it drips out correct? did you have to run the engine for a few minutes to pump all the old fluid out or anything?

I've heard that amsoil ATF is safe for the B&W trannys would that be better than dextron?

lucky131969

Yep, huge improvement. There is just no reason (unless you are doing auto-x events) to run synthetic fluid in the trans. A lot of guys post about how smooth the shifting is after switching to synthetic....but it's their first fluid change...so they have nothing to compare it to...just the old fluid. Truth is, just changing the fluid will make a difference, be it regular or synthetic fluid.
Just follow the service manual procedure....piece of cake.

You'll find plenty on this forum to say yes...

How in the world did airplanes fly, cars race, and tanks fight in wars before synthetic fluid...?

98BuickRegalGS

So Syncromesh isnt synthetic?

98BuickRegalGS

http://64.209.142.240/faq/tutorials/tranny.htm

1Sweet66

Thanks 98BuickRegalGS ! That's exactly what I was looking for and I already have the pump!

Off to the store to get 4 qts of Dexron ATF!

Smokin Joe

Had the stock stuff through 40k.

Switched to Redline synthetic (not sure which one, but talked to a Red line tech before buying) to 85k. The last 20k or so, reverese became harder, and neutral to 1st is stiff...shifting seems to become slightly tougher. Also, I have a trans leak since about 75k.

Switched to Royal Purple from 85k-90k (syncromax). Didn't notice a difference in shifting smoothness.

Oldvetter

I ran Mobil 1 ATF in my 1998 Coupe for 50,000 miles, then it started grinding going into 6th gear. I changed to Amsoil ATD and it immediately stopped. Now 20,000+ miles later all is well.

DO NOT use Mobil 1 ATF with 1997-2000 C5s, they have paper blocker rings and it will damage them.

Mike99FRC

I'm using GM Synchromesh now. I did notice an improvement in smoother shifting on my 99 FRC.

happa

I use Dexron ATF and havent had any issues for 20k+ miles

RyanR0101

'98 with 114k on the clock. Prior owner used the GM fill up until about 106k when I went to AMSOIL ATF. No problems.

FlyboyZR1

I bought the Amsoil Synthetic ATF at NAPA and put it in my 2000 ... shifts very smooth, no problems at all.

GettnBetter

The Mobil 1 ATF for me was horrible. Hard to put in 1'st gear, reverse required double-clutching, shifting hard 1'st to 2'nd and 3'rd was slow and not very smooth. That was with brand new Mobil 1, not once but twice I had the fluid changed. Horrible stuff both times.

I finally went with the Amsoil ATD. A little more durable fluid than the Amsoil ATF. It made a huge improvement. Shifts are silky smooth. I noticed and immediate improvement.

I made the change primarily because 4'th grinds. It still grinds in 4'th even after the ATD. I've read many other 97-2003 owners complain about 4'th. My tranny is the older style 6 speed without the carbon syncros.

c3andc5

I have been running Mobile 1 ATF since my first fluid change at 25,000 miles. I used Mobile 1 again when I replaced the fluid at 50,000 miles. Now I'm at 67,000 miles and my 6-spd shifts EXACTLY the same as it did with the original, factory fluid. I have not experienced any problems or issues regarding shifting performance.

C66 Racing

For those looking for the AMSOIL ATD mentioned above, this is the fluid:
AMSOIL Torque-Drive Synthetic Transmission Fluid (product code ATD1G - you'll need a gallon for a 6 sp manual)

For the DIYer, this comes in handy:
AMSOIL Hand Pump (product code G2039)

Ordering info in my sig. Feel free to PM with questions on the AMSOIL Preferred Customer Program which allows customers to buy at dealer wholesale, about 25% under retail.

TGstring

98 coupe
running exactly what the guys who engineered the car recommend:

regular Dextron auto tranny fluid.

tranny shifts fine at 95,000kms

I don't pretend to know more than the guys who built my car... so I'll listen to their directives.

longdaddy

if the rings are not an issue, i would vouch for amsoil ATD (thanks, subdriver, I think I am still using your code). I tried Redline too but in my experience shifter feel if more consistent with amsoil once the temperatures go up.