280zsteve

So, I was curious if this forum had a write up on how to change the transmission fluid in the automatic A340/A341. I came to the conclusion that there were write-ups on it, but they involved getting under the car and either removing the drain plug or pan to remove only 2-2.5 quarts of fluid over time or were very vague in their description of the process. Of course I mean no disrespect in saying that, but I feel I can contribute to helping anyone who's curious about doing this flush.

This write up will cover how to change the fluid in the LS400 and most automatic transmissions that utilize an external transmission cooler. If you don't feel comfortable with this or you feel this is unsafe for the transmission, I've done this to every vehicle I've owned and have never had a problem with it if you follow the process correctly. Also as far as I'm concerned, the bare bones of this process is what any independent shop or dealership performs with the exception of the $4500 machine to exchange the fluid. Not to mention this process saves upwards of $100 if you were to take it to a shop or stealership. The fluid that is used at a shop is not Toyota fluid nor is it the best quality, generally it is just bulk fluid that will go in Buicks, Fords, Chevys and Toyotas. So the upside to doing this process is that the fluid is factory.

First things first, ordering the fluid. I used 12 quarts of factory T4 fluid which is what Toyota would have used from the in 1997. I bought it off of eBay and it cost me $85 with shipping. Depending on what kind of tools are around you, you may need to buy some of the items I used to do this flush which were...

Pliers
Long nose funnel
2 one gallon milk jugs (or one jug and one bucket to place the old fluid into)
12 quarts of T4 transmission fluid
6 feet of 8mm-10mm hose (Just something to extend the input line for the cooler)
A vacuum connector (Unless someone can watch the fluid fill the jug for you)
Tape

This flush was performed on my 1997 LS400 with 199000 miles on the odometer, which means this process could be performed on any LS400 from 1990 to 2000 I believe. This can also be performed on most vehicles with an external cooler as mentioned above.

Start by safely jacking the car and placing it on jack stands. I found this to be time consuming because of the skid plate directly blocks any placement of the hydraulic jack, yet to take the skid plate off it has to be raised... Anyway once the car is up in the air remove the skid plate if you haven't already done so.

First obtain an empty single quart bottle, oil/transmission/power steering quarts work, then find an empty gallon milk jug. Fill the empty quart with water and then place the water into the jug, mark the jug where the water is leveled at. Then repeat the process for the second quart and mark it off. I do 2 quarts at a time because I feel comfortable with removing that much fluid at a time from the transmission and the process goes by quicker instead of only doing one quart at a time. Here's the marked jug;



Locate the transmission lines going to the radiator, the cooler is placed inside the radiator for cooling. The line you're looking for is towards the passenger side, view the picture below;


Next, if you are performing this process alone find enough hose and a fitting that can attach to the cooler line to reach a one gallon jug sitting in the engine bay. With a pan under the area of the cooler line, detach the line from the radiator and attach it to the fitting with the hose that extends into the engine bay. Be sure that the lines are snug or use a clamp to ensure they won't fall apart while you're in the process of filling the jug... if you don't it can get really messy, believe me I know. You're gonna find that the jug wants to fall over when the hose is placed inside of it. I used tape under the jug to stick to the core support to keep it from falling over, however I ended up just directly taping it to the core support. View the pictures below for a idea of how I attached the extended hose to the cooler line and the set up from the cooler line to the jug;





Now that the jug is secure and the extended hose is placed inside the jug, check that when sitting in the divers seat you can visibly see the marks on the jug. See picture below;



Start the vehicle. You'll find that the fluid fills the jug to the two quart mark in roughly 16 seconds. When doing this part you'll find that after shutting the vehicle off there are a few ounces of residual oil that raises the level to above two quarts, so shut the car off at about 1 and 7/8ths of a quart and it should be on the money. Take the marked jug and place the dirty fluid into the other jug (or container of some kind). Then place 2 quarts of the new fluid into the transmission through the dipstick tube using a long nose funnel. Repeat the process for the other 10 quarts of fluid now. View pictures below.;




Now that you've completed the above process, remove the extended line and attachment from the cooler line, reattach the cooler line, and clean any old fluid from the vehicle. Before taking a test drive, let the car idle for about 15 minutes to ensure there are no air pockets in the system. Take the vehicle on a long test (30-45 minutes) drive to heat the transmission up to full temperature and check that the level is correct, top off as needed.

jaaa

Only critique I'd have for what you did is to remove the other line on the oil cooler and hook the line that goes to your jug directly to oil cooler so that you can flush through the cooler too. I do a variation of this by doing a pan dump first and then pretty much follow what you are doing.

280zsteve

@jaaa That makes sense, that never occurred to me. I'll have to do it that way when I perform the flush on my SC. I appreciate the input.

Sin1UZFE

Very nice, been seeing these on youtube...but my luck id be the one to screw it up

Fit1too

Excellent write up and pix. Really appreciate the your effort!

Sherl

does the 98 has same line as 97?

280zsteve

Yeah, it'll be very similar to the above process.

lsghost

Can someone confirm a 2000 LS400 has an oil cooler? Seems they do not.

400fanboy

https://www.clublexus.com/forums/ls-...ml#post9894967

paulo57509

Most all auto transmissions have a cooler in the lower tank of the radiator. The only exception that I know of are some GM TH350's that were installed in the Vega and Nova. These were air cooled.

If you look at where the cooler lines exit the transmission, the line exiting the front of the transmission is the pressure; the one in the rear is the return.

lsghost

Ok - i was confused by post #2 by jaaa @ https://www.clublexus.com/forums/ls-...-pictures.html. He says to "remove the other line on the oil cooler and hook the line that goes to your jug directly to oil cooler so that you can flush through the cooler too". What is this cooler?

Yamae

That cooler is the lower part of the radiator.

perrobot

I'm doing a flush on my 1995 LS400 and following this process. Just want to confirm that the the the hose should be connected to the outlet which is the right transmission line on the cooler looking up from underneath towards the front of the car. Thanks!

djamps

Just did this... passenger side (left side, looking at front) is the pressure line. However as someone noted, it's easier to attach a drain hose to the driver side cooler exit than teeing into the pressure line, plus it flushes the cooler this way.