VAM1

I’ve read many posts but wanted to see if there is a Lexus technician that can chime in. Question is do I have the Tranny Oil changed and if so should I just do the 4 Qt or have the entire unit flushed. Tranny seems to shift nicely but 1st gear seems to wind up fast. Almost feels like the torque converter is catching up to the gear. LS was just purchased and I am coming off a vehicle that had a CVT so I am not us to an 8 speed transmission. I know the LS granny is a sealed unit so you can’t even check the fluid level not unless you check the overfill plug. I’m really trying to see what the MFG suggests. I really don’t trust the dealer.

Anfanger

It is funny to me that you think a Lexus technician has better knowledge than this forum.

VAM1

Definitely not but I cannot validate what the MFG suggests. So I am thinking maybe a Lexus Tech that has worked on and is familiar with a LS transmission can offer some advice. Dealerships will offer any service to drive profits up. When a car has 126,000 and is not under warranty anymore they can have a field day.

Anfanger

What I have found in the manufacture manual was steps to take if something goes wrong. I haven't seen any advisory regarding maintaining the transmission. But based on experience of LS460 owners, it is possible to conclude that some transmission issues can be be completely fixed by dropping the pan w/ the strainer replacement (sometimes not required). These days, as you stated, many dealers understand that there is money to be made on services that are not required. It puts us in a weird position where we want to take of care of our cars but we are being taken advantage of while trying to do just that.

I too had gear (3-4) switching issue not so long ago. After dropping the pan, replacing the strainer and 4 fresh quarts of transmission fluid, the issue went away.

One of the most important advantages of forums like this one is collective knowledge and experience of users. I think, it gives you necessary tools to make a decision how much, what and how.

sha4000

iTrader: (1)

Doing a drain and fill won't hurt and is a good option. IMO when you punch the pedal the rpms jump and there is a delay before it drops down to catch up with the great for lack of a better term but this is normal for this car. I completely flushed the fluid myself when I bought the car so I knew where my starting was going forward. A flush won't change the characteristics of the transmission but maybe an ECU flash can help. The dealer will probably tell you that the ECU is up to date though.

VAM1

I am planning on changing the strainer and doing a partial fill. Can you recommend or confirm my steps? My original thought would be to
1. Heat the oil.
2. Drain the pan.
3. Drop the pan.
4. Change strainer and O-Ring
5. Replace Pan with new gasket.
4. Refill with WS until oil comes out overfill.

yyymmm31

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Overall, your steps are good, except that Lexus service manual requires that checking the level of transmission fluid (when you see the transmission fluid from the drain hole becomes a thin stream) should take place between 35-42C (95-108F). If you have Techstream, use Techstream to monitor the transmission fluid temperature to ensure that you measure the transmission fluid level at the right temperature range. Additionally, if you don't like your transmission's behavior, you may use Techstream to reset the transmission memory and the transmission will learn from your driving habit to adjust its response accordingly. Another important note is that you need to keep the engine running/idling when you measure the transmission fluid level. Otherwise, you will end up with less transmission fluid in the pan than required. Caution: the transmission fluid refill plug and drain plug are soft and could be easily stripped (it happened to me). Don't over torque them. In fact, as soon as the washers are crushed, stop torquing them further. Additionally, use new washers for the plugs or you will have leaks. Another important note is to remove the 24mm fill plug first. If you can't remove it, don't drain the transmission fluid.
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VAM1

Okay so when I bolt up the pan and maybe after adding the first quart of WS I should start the engine and monitor TechStream for the oil to heat up?

yyymmm31

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Not exactly. The way I did it is that I measured the amount of the old transmission fluid that came out. It was about 3.5 qts. I added about 0.5 qt more than the amount of the old transmission fluid (i.e., total 4 qts) to the transmission via the 24mm refill hole. I then loosened the overflow drain plug a little bit to make it easier to remove. After that, I started the engine and watched the transmission fluid temperature on Techsteam screen. When the transmission fluid temperature reached 35C, while the engine was still idling, I removed the transmission fluid overflow plug to let transmission fluid flow out of the pan. When the the transmission fluid flow became a thin stream, I re-installed the overflow plug with a new washer. Please see the important note that I added in the above posting about removing the 24mm refill plug first before removing transmission pan, etc., to ensure that you don't end up with removing the transmission pan but can't remove the 24mm refill plug. Here is the torque and part information that may be useful to you:

Transmission pan drain plug gasket: 35178-30010 (drain plug part#: 9031110011,9034110011)
Transmission pan over flow plug gasket: 35178-30010 (same as drain plug gasket)
Transmission WS fill 24mm plug o-ring (gasket): 90301-15004; plug 90341-18059
Transmission filter part number: 35330-50030
Transmission pan part number: 35106-50050

Techstream screen for checking transmission temperature:
Go to “Engine & ECT” screen,
then go “Data List” on the left panel,
and view “A/T Oil Temperature 1” to watch the transmission fluid temperature.
Transmission check level temperature range is: 95-108F or 35-42C

Transmission Torques:
Overflow check plug (10mm hex): 15 ft lbf
Refill plug (24mm): 29 ft lbf
Drain plug (14mm): 15 ft lbf
Transmission pan bolts: 66 inch lbf
Transmission filter bolts: 8 ft lbf

Anfanger

Well, there is no issue if you can't remove the refill bolt. You always can fill the transmission through the overflow drain, though it might take couple times.

VAM1

I replaced the spark plugs yesterday and had to remove the battery. I did notice that the transmission is shifting so much better now. Is this because the computer that controls the tranny is re learning my driving characteristic's?

VAM1

I am planning on doing this on Monday. After refilling the tranny with WS and bringing back to correct temp should I have a helper place the car in drive or leave it in park to drain the excess fluid out the overfill plug? I plan on adding 1/2 quart extra to the measured volume that I had removed from the pan.

yyymmm31

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There is no need to have a helper for this procedure. Park your car on a flat ground. After you connect the Techstream, start the engine, while parking brake is applied and the wheels/tires are blocked with tire blockers, shift the gear from P to each gear for 2 seconds to help the transmission fluid circulate, and back to P, and repeat it until the right transmission temperature is reached. The transmission temperature rises gradually. Once the transmission temperature reaches 95-108F or 35-42C on Techstream screen, place the shift in Parking position, while the engine is idling, you'll have plenty of time to remove the overflow plug, wait for the transmission fluid become a thin stream, and then install the overflow plug with a new washer/gasket to complete the procedure.
See the YouTube below for reference. Although it is a LX470, the process is the same.
https://www.youtube.com/watch?v=ej_6BZpK3gg---
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