FAST99Z

Just spent $100 for 12 quarts of Mobil 1 Atf for a complete TC and tranny change. I have heard some people say that synthetic ATF is BAD for a transmission and I don't understand if that is so. What do you think?

Colonel

Slippage is bad in an automatic (and that's an understatement when speaking of the 3-4 clutch pack.) I hope synthetic doesn't promote that (as in, if it's slicker.)

Jorday

I've heard that it's a good idea to stay away from it, but have not had any experience with it myself. Most of the transmission places I talk to say to use regular fluid.

Jordan

Doc

iTrader: (9)

You paid 8.33 per quart? There seems to be a lot of panic on these boards when it comes to synth atf. Horror stories of trannies spewing their entrails everywhere. I would think that if all of that were true people would be standing in line for the class action law suit. ATF too slippery? It's oil. I wish I had the time to scientifically prove or disprove this myth. For now though just because "My mechanic, Crazy Kooter, sez "Dat stuff be bad," has gotten enough airplay on this board. Prove it.

SDB

iTrader: (7)

I was told by Carl Rossler to use conventional trans fluid, I have used Synthetic in the past with OK results, no better or worse than conventional. i am using Castol ATF now in my stock trans, and will probably use it in my Rossler built trans I will be getting this winter/spring. I see that on his website he does sell Red Line and has told me that Royal Purple synthetic ATF is OK to use. THe best thing is to change it often, as opposed to using synthetic and thinking it wil be good all year. Get a drain plug in it and change out 4-5 quarts every couple months and I bet it will be better than using synthetic once a year...cheaper too!

Big Noodle

Colonel

"ATF too slippery? It's oil."

Yes, I would be concerned if it were too "slippery"...as in not having enough friction modifiers. Yes, it is oil (well, if you call hydraulic fluid "oil"), but it's sole purpose is not to reduce friction. In fact, in some regards it should aid in friction. However, if it meets the same certifications that Dextron III meets, it should do this just as well. So, does it?

Doc, how long have you been using synthetic ATF and what have your experiences been with it?

Ragtop 99

iTrader: (7)

I agree with SBD. FWIW, Mike at Yank has stated that too slippery can lead to issues as well.

02 SOM WS6

FWIW, Mike at Yank changed the converter in my old Z28. Converter was full of Mobil 1 when it went in. At the same time he dropped the pan and changed fluid & filter & filled with Mobil 1. Drove at least 40000 miles after that with lots of 1/4 mile passes. Car had no extra trannie cooler. It gets pretty warm down here in the Houston area. Transmission was still going strong when I traded the car in at 52000 miles.

Les

Raughammer

I just use whatever is on sale.

Seriously. Never had one single tranny problem on the stock one or the Yanks.

Synthetic is just for your YOUR peice of mind. If it makes YOU feel better..... then buy it.

Good luck

Superman

Better to change the fluid more often then use better(debadable) fluid IMOP.

42NightZ28

i was told by Speed inc and Mike ant Yank that Amzoil Powershift 10w is ok to use both in the Stage 2 trans and the Converter so thats what i have been using.

horist

when I got my FLP Stage IV i was told NOT to use synthetic...

joecar

I use M1 synth. ATF and I noticed that after my daily commute the end of the dipstick is much cooler compared to non-synth. ATF; heat degrades ATF so cooler ATF is good.

I have just over 15K miles on M1 ATF and no problems.

My WS6 is stock other than I used a Predator to firm up the shifts (+10%) and reduce the shift times (-10%).

FAST99Z

I went with the Mobil 1 atf because the synthetic engine oil has such a good reputation and I hoped the same would be true for synthetic atf. Next time I will probably save the bucks, use a good Dextron III and put in a tranny temp guage to monitor temperature.

Would appreciaite some more advice on the benifits of synthetic (good or bad)

Colonel

"Doc, how long have you been using synthetic ATF and what have your experiences been with it?"

Doc, you out there?

Anyone who wants cooler fluid temps should get a tranny cooler rather than hoping synthetic will run cooler. I like having a tranny temp gage in the car.

joecar

Update: I dropped the pan on Saturday (after 15K) to change the filter: there was almost no sludge, and the fluid looks Very clean (compared visually in a glass with brand new fluid, no visible difference detectable; smells new).

There was less sludge with synth than when I was using non-synth.

I will open this filter up just to see what it collected,
but I'm fairly certain there won't be anything.

I "launch" aggressively about 4 or more times a week when getting on the freeway; here in So. Cal. we have "metered" freeway on-ramps (signal turns green, you go )

Doc

iTrader: (9)

Col, Sorry for the late reply, been having too much fun. I used the Mobil 1 ATF for one "cycle," which is about six months. I have a B&M deep pan and cooler. The car is not a daily driver. Although I have gotten stuck in traffic and I haven't seen much difference in temps btw synth and reg; with the fans set in the PCM to come on earlier. I think if you perform regular maintenance + with a deep pan and cooler reg hyd fluid is fine. I was just "fishing," to see if anybody has gone the distance and really tested this stuff via hyd ananlysis. The bottles'lable and Mobil 1 website are very vague. I am sorry, I did not want come off rude with my comment about the "slippery," stuff. I just would feel better with a term like viscocity or something that can/could actually be measured so we could compare. I am on vacation right now but, I do believe the guys down the hall at my work could work up an hyd analysis.

Doc

iTrader: (9)

One other thought,
Product Description
Mobil 1 Synthetic ATF is a synthetic fluid designed that meets the demanding requirements of modern passenger vehicles. The synthetic baseoil composition enables excellent performance even in the severest of operating conditions. It offers outstanding gear shifting and power transfer performance. Versus conventional ATF fluids, the inherently high viscosity index and stability of Mobil 1 Synthetic ATF protects against thermal breakdown at high operating temperatures, while still providing outstanding performance at ambient temperatures as low as -54º C.

Features
Advantages and Potential Benefits
Enhanced, long-term frictional properties Improves and extends transmission efficiency, smooth shifting performance and fuel economy
Exceptional thermal and oxidation stability Keeps transmissions clean to extend life and performance even under severe driving conditions
Outstanding film-strength and anti-wear properties Significant wear reduction and longer transmission life
Excellent low-temperature fluidity Provides prompt and reliable lubrication at ambient temperatures down to -54º C -<That's -65 F>
Exceptional shear stability Viscosity retention even under the severest heavy duty, high temperature operating conditions
Compatible with mineral ATF fluids and all common seal materials Reduced concern in top-off emergencies and excellent leakage control

Typical Properties

Mobil 1 Synthetic ATF

Viscosity, ASTM D 445
cSt @ 40º C 34 <104 F>
cSt @ 100º C 7.6 <212 F>
Brookfield Viscosity, ASTM D 5293
-cP @ -40º C 5190
Viscosity Index, ASTM D 2270 199
Pour Point, ºC, ASTM D 97 -54
Flash Point, ºC, ASTM D 92 236
Density @15º C kg/l, ASTM D 4052 a
Colour Red

So they tell you how cold you can use this stuff. Uh I am in Hot *** Florida and I will never see -65 F. Notice the viscosity numbers they give...@ 104 F and 212 F I don't know about you guys but I don't want my tranny going anywhere near 212 F. I don't know what the "CST," numbers mean in relation to those temps? The point at which the Hyd Fluid is breakin down? Help, someone who is sicker than I am for performance explain this. Thanks.

FAST99Z

tttop

MyLS1Hauls

iTrader: (2)

FWIW, numerous people have had poor results with M1 ATF in their 6spds. Its hard to change gears, which leads me to believe its a slipperier fluid which prevents the synchronizers from working as fast as they should.