Hi, I have a fully rebuilt Lexus IS300 AT transmission and am currently running the Toyota T-IV fluid which I believe is very similar to Dexron III. I get very smooth shifts on normal driving, but when Im WOT it lags, sometimes slips, and sometimes causes me to hit the rev limiter. I know a person that has ran the Amsoil Type F ART in the same transmission and swears that it will run fine and better, but Im still hesitant. I purchased 16 quarts of the Amsoil ART, but need to get second opinions before I flush out my type-iv fluid. If it runs too roughly would I be able to add friction modifiers as needed to comfort the shifts? Thanks
Amsoil Super Shift ART in a Type-IV/Dexron 3 Trans
- Thread starter KerryB
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T-IV is NOT similar to Dexron III. T-IV has a higher level of friction modifiers, such as what is found in Chrysler ATF+/+3/+4. Amsoil Supershift more closely resembles Ford Type F, which has even fewer friction modifiers than Dexron III.
Your AT will shift gears more quickly, which can easily wear out a factory transmission. However, since I see you did some serious modification to your car, all bets are off when it involves transmission life.
I think you should probably use it, because many drag racers use Type F in their Dexron III/Mercon transmissions because of their unique needs.
Your AT will shift gears more quickly, which can easily wear out a factory transmission. However, since I see you did some serious modification to your car, all bets are off when it involves transmission life.
I think you should probably use it, because many drag racers use Type F in their Dexron III/Mercon transmissions because of their unique needs.
Your choice - I probably would have progressed - Amsoil: ATF - ATD - ART.
Give it a shot.
Where did you buy the ART?
Give it a shot.
Where did you buy the ART?
Fuzzy logic and adaptive TCM programming can cause it to choke. Amsoil ATF would have similar shift quality to T-IV, as would most universal ATFs. Being a full synthetic, that would a good choice---- Amsoil ATF, and not ART.
The problem with lower(ATD) and non-HFM'd fluids(ART) is that the TCU programming could drop the line pressure to smooth out the shift. You don't want that to happen.
If you're unhappy with the shift speed, then maybe that fully rebuilt transmission isn't as 'fully' as you thought?
Check to see if there are any programmers that can address the transmission parameters. Even a factory dealer installed update might be better then what the vehicle shipped with.
You should also monitor transmission fluid temperature. It may be possible to acknowledge that 'someimes slips' with ATF temperature. If it slips when too cool, you need an ATF thermostat. If it slips when too hot, you need a big ATF cooler. Another option is to trick the ATF temp sensor by replacing or modding it with a resistor. Again, you'll need to know the temp/shift/PSI parameters to select the best resistor to trick the TCU to provide maximum PSI or shortest shift duration.
Find a shop that can modify the valve body for quicker shifts. A little more line pressure, a little less accumulation, a little more ATF flow through VB porting, can go a long way in speeding the shift.
How old is the T-IV? If it has more then 10k miles on it, its probably toast already. Flush it out and get an ATF UOA.
Excessive wear caused by excessive engine output, will be suspended in the ATF. That wear can mess up shifts. Toss some sand on a basketball court and see how the players react. Get a good fullflow ATF filter, like the permacool unit with a quality PH8A sized oil filter(pureone, amsoil, x2, napagold, stilko, trasko). The filter will keep the fluid free of particles that can get inbetween friction bands/clutches.
The problem with lower(ATD) and non-HFM'd fluids(ART) is that the TCU programming could drop the line pressure to smooth out the shift. You don't want that to happen.
If you're unhappy with the shift speed, then maybe that fully rebuilt transmission isn't as 'fully' as you thought?
Check to see if there are any programmers that can address the transmission parameters. Even a factory dealer installed update might be better then what the vehicle shipped with.
You should also monitor transmission fluid temperature. It may be possible to acknowledge that 'someimes slips' with ATF temperature. If it slips when too cool, you need an ATF thermostat. If it slips when too hot, you need a big ATF cooler. Another option is to trick the ATF temp sensor by replacing or modding it with a resistor. Again, you'll need to know the temp/shift/PSI parameters to select the best resistor to trick the TCU to provide maximum PSI or shortest shift duration.
Find a shop that can modify the valve body for quicker shifts. A little more line pressure, a little less accumulation, a little more ATF flow through VB porting, can go a long way in speeding the shift.
How old is the T-IV? If it has more then 10k miles on it, its probably toast already. Flush it out and get an ATF UOA.
Excessive wear caused by excessive engine output, will be suspended in the ATF. That wear can mess up shifts. Toss some sand on a basketball court and see how the players react. Get a good fullflow ATF filter, like the permacool unit with a quality PH8A sized oil filter(pureone, amsoil, x2, napagold, stilko, trasko). The filter will keep the fluid free of particles that can get inbetween friction bands/clutches.
very good info thanks! I'll def take your advice
My situation really is not that bad as I put it to be. It doesnt slip often and I do monitor temps. Its always in perfect operating temp as what the manual stated ~150F. SOemtimes it slips and sometimes it doesnt. More boost = more slip. I remember that my tuner suggested me to use a Dexron 3 fluid instead of the toyota t-iv because it has less FM's so its less prone to slip.
so it looks like i will be exchanging my ART for the regular ATF or is any other ATF you would suggest?
...how does Redline ATF compare to Amsoil ATF?
My situation really is not that bad as I put it to be. It doesnt slip often and I do monitor temps. Its always in perfect operating temp as what the manual stated ~150F. SOemtimes it slips and sometimes it doesnt. More boost = more slip. I remember that my tuner suggested me to use a Dexron 3 fluid instead of the toyota t-iv because it has less FM's so its less prone to slip.
so it looks like i will be exchanging my ART for the regular ATF or is any other ATF you would suggest?
...how does Redline ATF compare to Amsoil ATF?
I have used Mobil1 Synthetic Mercon V in several cars, and I like the stuff. It also works well where DexIII is needed. It doesn't have the friction modifier levels found in T-IV.
That in mind, I never used it in any specially modified vehicle.
That in mind, I never used it in any specially modified vehicle.
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