99 LS400 Dexron III?
08-21-13, 07:50 AM
#1
Driver
Thread Starter
99 LS400 Dexron III?
My brother just bought an extremely clean 1999 ls400. All the maintenance has been done including timing belt and water pump at 90k miles. The car has 130k miles now. I was looking through the 3 inch stack of service records and found the transmission fluid flush receipt. It was done at an indy shop and the mechanic used Dexron iii. That was at 65k mile and it was never changed since. The fluid is still red and does not smell burnt. Transmission shifts fine except small slip when cold start.
I guess my question is should i drain and fill with dexron iii or flush and use newest t type fluid?
I guess it also seems dexron iii is not a problem even after 65k miles.
I guess my question is should i drain and fill with dexron iii or flush and use newest t type fluid?
I guess it also seems dexron iii is not a problem even after 65k miles.
08-21-13, 08:11 AM
#3
Driver
Thread Starter
I will, just to be safe. Not to be argumentative but i was wondering if theres actual facts or evidence that dexron iii will damage the transmission. I wonder because the dexron iii was in there for 65k miles with no ill effects. Am i on borrowed time? A ticking time bomb because dexron is in it?
08-21-13, 08:13 AM
#4
Lexus Champion
yes, you should start a drain and fill ritual of every other oil change!
transmissions are expensive!
I would use T-IV from the dealership, starting now.
A flush is not required nor recommended. The flush will happen naturally, after a few drain and fills. T-IV is backwards compatible, the fluids are OK to mix.
transmissions are expensive!
I would use T-IV from the dealership, starting now.
A flush is not required nor recommended. The flush will happen naturally, after a few drain and fills. T-IV is backwards compatible, the fluids are OK to mix.
08-21-13, 08:15 AM
#5
Lexus Champion
08-21-13, 08:22 AM
#6
I did find this:
T-IV is basically a standard Dex-III product with more advanced friction modifiers. Since the time it was developed the whole industry has advanced and the new fluids surpass the standards of both. T-IV does not have superior basestocks or fluid qualities. T-IV was designed to be backward compatible with Dex III.
Last edited by Lavrishevo; 08-21-13 at 08:32 AM.
08-21-13, 08:32 AM
#7
Lexus Champion
Dexron III is not the ideal fluid for shift perfection, but it is very similar to T-IV and is fine in a pinch and will not ruin or even harm your Aisin A-series transmission. - In fact, the A340E found in my 96 model, which is the same exact transmission with one less gear than the A650E in the '99, came from the Lexus factory with Dexron II 
However, something than many LS400 owners do, not coming to a complete dead stop, before shifting from reverse to drive and vice-versa, will ruin the transmission!
However, something than many LS400 owners do, not coming to a complete dead stop, before shifting from reverse to drive and vice-versa, will ruin the transmission!
Last edited by LScowboyLS; 08-21-13 at 08:42 AM.
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08-21-13, 02:25 PM
#9
Lexus Champion
a 10 minute drain might yield 2.5 quarts, whereas overnight might yield 4 or more
the dipstick is the final arbiter, use the cool setting for a rough fill, then get tranny really hot from an extended drive of half an hour or more, then on a very level surface, use dipstick hot mark for precise top off
08-21-13, 05:56 PM
#11
Dexron III is not the ideal fluid for shift perfection, but it is very similar to T-IV and is fine in a pinch and will not ruin or even harm your Aisin A-series transmission. - In fact, the A340E found in my 96 model, which is the same exact transmission with one less gear than the A650E in the '99, came from the Lexus factory with Dexron II
However, something than many LS400 owners do, not coming to a complete dead stop, before shifting from reverse to drive and vice-versa, will ruin the transmission!
However, something than many LS400 owners do, not coming to a complete dead stop, before shifting from reverse to drive and vice-versa, will ruin the transmission!
Dexron II =/= Toyota T-II. not even close.
i'm more likely to think they used the right fluid used the wrong line-item when writing it up. I've never heard of any place using straight D3/M fluid in an LS and it not causing problems.
08-21-13, 07:05 PM
#12
Lexus Champion
It didn't ship with DEXRON II, it shipped with Toyota T-II, the predecessor to T-IV. Look in your '96 owner's manual and it'll say the same thing.
Dexron II =/= Toyota T-II. not even close.
i'm more likely to think they used the right fluid used the wrong line-item when writing it up. I've never heard of any place using straight D3/M fluid in an LS and it not causing problems.
Dexron II =/= Toyota T-II. not even close.
i'm more likely to think they used the right fluid used the wrong line-item when writing it up. I've never heard of any place using straight D3/M fluid in an LS and it not causing problems.
and I am not saying Dex II or III is optimal for shift quality, I am saying it won't ruin the transmission.
if you want to catch the cowboy in an error, probably A/C, transmission, and ECU are not good areas to target
Last edited by LScowboyLS; 08-21-13 at 08:01 PM.
08-21-13, 07:51 PM
#13
Lexus Champion
yes
yes, drain & fill is easy and prolongs the life of the transmission, every other oil change is a good, yet safe, frequency
as you drain & fill over time, you are, in fact, "flushing" the transmission and getting it to pure T-IV, but in a gradual, gentle way to therefore avoid problems of shocking the transmission
always use a new drain bolt gasket and drain bolt! (the pair is around $5 at any Toyota dealership)
Cowboy, is there a reason why you recommend every other oil change instead of every oil change?
as you drain & fill over time, you are, in fact, "flushing" the transmission and getting it to pure T-IV, but in a gradual, gentle way to therefore avoid problems of shocking the transmission
always use a new drain bolt gasket and drain bolt! (the pair is around $5 at any Toyota dealership)
Last edited by LScowboyLS; 08-21-13 at 08:00 PM.
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