Lexus LS 400 Tranny - questions about shift soli.

[yummy88]

I have a 91 LS 400 with 200K miles and awhile back I complained about tranny slipping.

After driving the car around, I now feel that it might be the shift solenoid. The car would just drop into OD when car is going at 30 mph in the city. The RPM would then be around 1200 and engine would be lugging a little. And if I accelerate a little the tranny would shift so no issues with shifting to another gear.

Also is the shift solenoids affected by ATF? Meaning would flushing the tranny or rather dirty ATF affect operations of the tranny.

I have read that should a solenoid fail in the Lexus there are other solenoids to compensate but the net effect would be very sluggish response. No idea what that means.

 

[unDummy]

Yep, if the ATF can't keep the tranny clean, then the solenoid could bind up in varnish or crud.

Just about all my past cars(toyota, nissan, ford, mazda...) have shifted into OD very early. Its all about CAFE and MPG. Disable the OD or manual shift it. In my vehicles, I usually leave the OD disabled when city driving.

Some cars also start out in 2nd and require a lead foot for 1st gear starts from stop signs/red lights. Usually a programming change(aftermarket or dealer) can prevent it.

 

[Donald]

What is the history for your tranny with 200K miles? If it looks like driveway sealer its time to change the fluid, filter, drop the pan, etc.

If the ATF is in bad shape, its still fine to change the fluid, get a flush, etc, but the pan and filter need to be serviced first to get a handle on things.

A Magnefine filter should help also (after the ATF change).

 

[biomed_eng_2000]

Sounds like time for an Auto-RX transmission clean.

http://www.auto-rx.com/auto-rxnet/index.html

Don't worry, the same formulation is used in $30 million printing presses too.

 

[biomed_eng_2000]

Oh yeah, this is what a LS 400 owner wrote:
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1998 [Lexus] LS 400 with 70,000 miles. Ran 8 oz of AutoRx in transmission for 1500 miles. I have had this intermittent "jerk" on takeoff from standstill since I bought the car with 30,000 miles. Well, well, I just finished doing a backyard flush this evening, refilled with Toyota Type IV ATF, drove it around to get fluid hot so I could get proper amount of ATF in tranny. Overfilled (why do I always overfill????) and had to suck a little out.

Guess what. So far I've had 20 or so stop and goes with no "jerking." Hmmmm...

I get confused when stuff I buy actually does what it is supposed to...
Gebo - Virginia
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