mlevk

Anyone know if I can flush the tranny myself ?

Is it possible to connect 2 hoses to the cooling lines,
one into a "full container" and one for draining ,
let the tranny do the work by starting the
engine and let it run until it is flushed out ?



Also , does anyone know if the 91 LS has limited slip diff ?

Lvangundy

I don't have the direct link, but there was a similar forum posted in the LS430/400 forums about my experiences with the trans flush. But if you do get it done, make sure you use Toyota fluid from the dealer. I'm not sure if you can do a flush because they use some kinda high pressure system. I know they flush 25qts of fluid through the transmission.

About the limited slip differential, I'd like to know too ;-)


1990 LS400
Socal.

Traveler

Hi,

The early 90 LS trannies never required a flush according to the manual. However, they get less than Lexus smooth if you do not refresh the fluid.

And when you refresh, you really need to use the expensive Lexus house brand of fluid -- neither other brands nor synthetics will deliver the same performance.

Since you are unsure about how to flush the fluid, consider refreshing it each and every time you change the engine oil/filter. This means removing the transmission drain pan drain plug and letting its 1/2 gallon of fluid drain out. When you replace the plug, you will need a new metal plug gasket from Lexus (usually free to $2.00 depending on the dealer). Fill the tranny from the check stick under the engine hood (this will require a narrow hose and a funnel if you do the work yourself).

As a warning, some Lexus maintenance shops will bill you for the entire gallon for this work ($24) when only 1/2 gallon is used. The justification is that the fluid must be used quickly when the gallon is uncapped so the fluid does not oxidize.

The dealers do not throw out the rest of the gallon but just use it in the next car down the line. Bit of a rip. Of course, you avoid this if you do the work yourself or just level with the service department that this practice is known to you.

As to the diff being limited slip. I believe the answer is that they are not (should check to be sure). On the models with traction control, when you disengage that feature there is NO limited slip. I suspect they were all built that way since trac was available and worked better than limited slip diffs.

Take care,
db

mlevk

Thanks so far for the replys.

I know about using TOYOTA TYPE 4 ATF , I hope everyone else does too.

Still doesn't answer my original question about letting the tranny
do the work of purging all of the ATF.
I'd like to get out most if not all of it. I guess I wouldn't consider it a power flush .

wwest

I would bet that more damage occurs to tranx due to "gofers" being used for "routine" tasks than would ever occur if the tranx fluid was NEVER changed out.

Tranx fluid has ALWAYS been formulated to allow particles to settle out and form a residue in the bottom of the case. Absent a failure of some type the only foreign particles available would be from the clutch pak surfaces. The only other reason to change this fluid out is if it becomes over-heated and that typically doesn't happen unless you are "towing" or again, something has failed.

The only reason thjis issue has come up is becuase Lexus is a single marque shop and with the product's extreme reliability their service bays have no work except for "make work" like this.

Take a look at a 90,91 0r 92 owners manual and then a newer one. Look around you, every concieveable product you can imagine has undergone significant improvements in the last ten years, yet the Lexus line's sheduled maintenance requirements have ballooned out of proportion.

The early LS had TRAC would eliminates the need for LSD.