'98 LS400, Do I Need A New Transmission?
#1
Driver
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After the car has been sitting for a day, I've noticed it take me 10 seconds to shift from reverse to drive, after a 10 second wait, the car shifts. The shifting action itself is smooth but it takes 10 seconds for it to start, the transmission is otherwise perfect and it's fine at highway speeds etc. If I have driven it earlier in the day it shifts perfectly upon startup. I got a Bluetooth scanner and it gave me a error code for the Shift Solenoid SLU, I replaced the solenoid (I made sure it was in fact the correct solenoid in the valve body) with a new OEM one and made sure to use T-IV fluid to replace the fluid lost.
Also, I tested the old solenoid and it turns out it was working the whole time! Nonetheless, the code went away (why did I get a code if it was working in the first place?) but still my transmission is still sluggish after it hasn't been started up in awhile. I did notice that I got a code P0763 for solenoid C after replacing the SLU solenoid, but solenoid C is only for the higher gears and my higher gears are perfect. Also, I've found two forum posts online with my problem but they never followed up on which solution worked for them.
Is my problem with something else in the transmission, or are the solenoids still the culprit here? What do you guys think?
Also, I tested the old solenoid and it turns out it was working the whole time! Nonetheless, the code went away (why did I get a code if it was working in the first place?) but still my transmission is still sluggish after it hasn't been started up in awhile. I did notice that I got a code P0763 for solenoid C after replacing the SLU solenoid, but solenoid C is only for the higher gears and my higher gears are perfect. Also, I've found two forum posts online with my problem but they never followed up on which solution worked for them.
Is my problem with something else in the transmission, or are the solenoids still the culprit here? What do you guys think?
#2
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Sounds like you have a problem with the pump in your torque converter. The fluid in the TC will slowly drain down into the pan after a day, or so, but is quickly drawn into the pump at startup. The pump then provides pressure for various clutch packs, depending on gear selection..The solenoids control which packs get pressurized.
Your problems with solenoid codes suggest loose connection issues with the internal wiring, and/or sticking solenoids due to dirty fluid, OR a pump that is losing it's prime. Was your fluid badly discolored, or very dark? That can cause these issues.
Your problems with solenoid codes suggest loose connection issues with the internal wiring, and/or sticking solenoids due to dirty fluid, OR a pump that is losing it's prime. Was your fluid badly discolored, or very dark? That can cause these issues.
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RA40 (04-01-19)
#3
Driver
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Something that may point to the issue.. If I put the car in drive, I previously mentioned that it takes awhile for anything to happen, but, if I push on the acceleration, it kinda jolts the transmission back to life life a lot faster than if I just waited for it to shift on its own. Sometimes, pressing on the acceleration is the only way to get the car to shift into drive. Do you think that could pinpoint the issue?
The fluid was brown with a slight tint of red, it needed replacing but it could've been far worse. That said, I did a drain and refill that replaced a quarter of the fluid, and nothing really changed at all.
The fluid was brown with a slight tint of red, it needed replacing but it could've been far worse. That said, I did a drain and refill that replaced a quarter of the fluid, and nothing really changed at all.
#4
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What debris was in the pan? If you found a lot of brown goo or metal particles in the pan, that's a sign of worn clutch packs. Having to rev the idle speed to engage the tranny is a sign of either a failing pump/ bad seals, or clogged fluid passageways. Either way, I'm afraid your tranny is on borrowed time , before major work will be necessary.
Last edited by fixmiester; 04-01-19 at 05:39 AM. Reason: Spelling
#5
Driver
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On the magnets in the pan, there was a bunch of goop stuck on them, I've seen pictures of stuff sticking to the magnets online, but mine were much worse. Really the whole bottom of the pan was covered in this goop, It had a different consistency the tranny fluid. There were also a fair amount of metal particles all the way of the bottom of the pan I drained the fluid into.
#6
Lexus Champion
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sounds like you have already cleaned your pan out, next I would do a tranny fluid one gallon flush, using the cooler lines to get a gallon out and then put the new gallon in, and see what happens.... and come back and let us know..
I done that to my 99 ls and i was NOT having trouble, but had 200k and wanted to freshen up the fluid..
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