suloh

My 1992 LS 400 has about 200K miles. I just bought it so I have no idea when the transmission fluid was changed. The fluid looks brownish red but there is no burnt smell. Car shifts fine. Should I go for the complete fluid change draining the ATF from tranny cooler line or should I just do the regular drain and refill.

If I were to do a drain and refill, how much fluid do I need?

If I were to go for the total fluid change, I will probably need 10 quarts to finally clean up the whole transmisson.

So what are your suggestions. I will be using TypeIV fluid. I am tempted with the complete fluid change.

sha4000

iTrader: (1)

just fush it all out and start out new

koolaidman

depends.
if ur having shift problems. do not change it
if the fluid smells burned. do not change it
go to the dealership and ask for a national history on the car
if its was done on a regular basis of 15-30k miles its ok to change
if it hasnt been changed in 50k miles with not very many intervals. do not change it
lexus recomends only doing a drain and fill
have u ever smelled burned trans fluid before
is there a difference smell of t4 and dextron.
there is a lot of questions that need to be answerd before changing it. because if u change the fuild. it starts to shift funny. then its time to either buy a new car or a transmission. and i was told all ls's use t4 but double check with ur manual

suloh

Today, I discovered that my tranny shudders when the torque Converter is unlocking (is that the right term?). And yes the shudder feels just like running over lane dividers or rubber strips. It has been well described in the forum but I have not found an answer. So folks suggest a complete ATF fluid change. I do not know when the last ATF was changed and if the correct Type 4 was used. Fluid smells ok, but it looks dirty. Maybe the safe way if to do the regular drain and refill and see how it goes.

koolaidman

so when ur car goes under 35 mph u get a shudder. sounds like time for a new trans. doing a drain and fill will only make it worse

suloh

The shudder only happens at about 40 mph when you accelerate gently and the tranny goes from lockup to 4th gear. Other than this shudder, tranny runs well and does not slip and shifts very smoothly.

It must be a rather common problems with the LS 400 as I see quite a few folks experiencing the same problem.

SC400-V8

iTrader: (1)

The shudder happened to me too, i dont think a new tranny is needed.

I had the exact same problem, when the car was in overdrive w/ lockup (about 40 mph) and acceleration was needed, it would downshift into 3rd and shudder. it felt like a lane divider. At first I figured it was just some road bumps, but then I realized it only happened when I needed to accelerate at those speeds.

I had a toyota dealer flush the entire thing and refill with type IV, and the shudder went away, runs perfect after that.

suloh

How many miles do you have on the SC400?? Is it still 85K.

suloh

I think I will just do the 2 quart drain and refill and see how it goes. With 200K miles maybe a complete flush might kill the tranny. Don't get me wrong, it shifts fine except for that 40mph coming out of lockup shudder (feels like running of highway wake up rubber strips).

If all is fine, I might do another drain refill maybe in 3k

RA40

iTrader: (6)

There have been a couple threads regarding not changing the fluid after a long interval. Either way, you are at risk of a tranny rebuild, that will come sooner or later. The alternate thought is change it and if it works out, you've caught it and may have saved off the rebuild. Some have had successful flushes while others with Dexron fluids have had the stuff float through the system and wreak havoc.

A $125 flush if it is successful is still is less than a $1,800 rebuild. YMMV

SC400-V8

iTrader: (1)

I think the shudder started at about 60K, I never really ascertained there was a problem until about 63 or 64K. I stated the problem after I read a thread here and my fellow members recommended I flushed it before it got worse, and that usually a flush is recommended every 15K miles or so.

I had it flushed by a toyota dealer taking special care that only type-IV was used and it shifts perfect ever since, I am now at about 90K miles.

How much does a mint tranny go for an SC400 anyway?

suloh

Just found out that transmission fluid was last changed 100K ago. Fluid is not burnt and not black. But it is maybe brownish. When I wipe the dipstick, there appears to be fine dark sediments (very fine). Car shifts fine.

RA40

iTrader: (6)

I'd discuss this with your trusted Lexus mechanic. You may try and PM VVTi about this and get his thoughts.

An alternate thought is thinking of this like coronary artery disease but with the tranny.

sha4000

iTrader: (1)

that is most likely regular wear of the gears considering you have 200k miles on it. i wouldnt worry but all you have to do is drain the pan then take it off and inspect the magnets in the bottom of the pan.there should be 3, there purpose is to catch the shavings b4 they have a chance to flow back through the tranny

suloh

BTW, is there a gasket when I drop the tranny pan?? Some say that you just use some sealant and that will be good enough. Anyone know the part number if there is a pan gasket.