Lexson

I just checked my tranny fluid today and its like barely coming up the dipstick on hot....so I parked it right away and wont drive it again until I fill it.
I just bought the car, so Im not sure how long its been low....could this be a problem? I seem to hear a small noise when I put the car into reverse (before actually backing out)....sounds like its coming from rear actually...and not the tranny.
Any ideas?

PERRYinLA

According to an ATF web page I once checked, a low level of ATF can cause slow engagement and slipping.

Overfilled transmissions, just like engines, can aerate the fluid, which changes its friction characteristics and causes shifting problems.

If your car was shifting smoothly, you've probably dodged the bullet.

SRQ400

To take the guess work out of you dilemma it would probably be a good time to change the fluid. Go to your Lexus or Toyota dealer and get a 4 liter can of Type T-IV Auto fluid about $35. Very easy to do, check search. Unlike older transmissions pre 1990 ours do work better/longer with just a little more fluid in them but no more than a half of a quart. If you live in a hot climate consider an external bypass cooler, could add years on to it

black sc

Check for leaks would be the 1st thing I would do. It should not go that low Check the differential fluid also.

JTJerryls400

be there (low fluid) after flushing
time before from P to R or D take long time.
Ach, and when fluid is low tranny pulls better and slips less.
That is strange pheno but THAT IS TRUE!!!!!!!
when my tranny fluid was low (about 1 litre) tranny was much crisper and sharper.
After I add fluid all become as always, gummy trany as always in lexus
I hate that gummy lexus tranny feeling (compare to Audi or Merc)
Jerry

wwest

"barely coming up the dipstick on hot"

Do you mean barely reaching the "hot" marking on the dipstick?

Or do you mean barely showing on the dipstick at all?

And sorry about this next, but "hot" for a transmission means about 20 minutes of driving, just idling (along) for long enough for the engine temperature to rise will not heat the transmission fluid enough to give a good dirstick measure.

Low fluid in your transmission will typically first be heard by a pronounced gear whine, much like a failing rear diff'l. The hydraulic pump in the transmission is typically a "gear" type, like the engine oil pump, and if the fluid is too low there is no lubricant for the pump "gears" and you hear the whine.

Also if the fluid is low the pump cannot build enough pressure to properly operate the analog computer (pre-95 Lexi) and fully engage the clutches, resulting in slow shifting and clutch slippage.

Lexson

hi there everyone.
ill try to clarify....west i meant there was barely any oil showing on the dipstick at all.
i had driven it for about an hour before....10-20 miles or so....then it had been parked for about an hour or two before i checked the level. right before that, i let the car idle until the needle was at the halfway point where it usually is (the engine wasnt completely cooled down and it was still at over 1/4 when i first started it).
the car seemed to shift fine....smooth as ever on road. like i said...i thought i could maybe hear a small noise when i shifted into reverse (once the tranny actually shifted). i did what the manual said to do....put the car into P, N, D, 1, 2, L and back.
so im not sure at all whether that noise from the rear was even due to the tranny....but if it was due to low fluid....will it go away once ive filled the fluid? (im out of town, so sunday)

wwest

Two hours, or maybe even one at the right ambient temperature, is enough for the fluid to cool and not show up to the hot marking. The fact that you re-heated, brought the engine back up to temp confuses the matter.

Since everthing seems to be operating normally I would drive it for about ten miles AFTER the engine is up to normal temperature, then check the fluid level. It's important that the car be on a level surface and that you insert the dipstick until it actually locks in the tube.

SCV8

Usually the car will freewheel either starting out,or between 1-2 shift,then violently engage into gear.
Check the shaft where the shifter goes into the trans,pan gasket.

Lexson

No, had no violent shakes at all. I did go to the dealer and get the Type 4....$31.00. Mental note....buy a good funnel!! Its hard to fill that stuff...because the lock that locks the tranny fluid cap and then the wires around it make it almost impossible. I had to rig something by making 6 inch piece of paper attached to funnel...and that was AFTER I spilled probably 10% of the jug all over the engine compartment when I tried to do it at gas station right after and the funnels didnt work.
So when the tranny is hot...the fluid level is also at hot. Great, looks good.
But like in the morning....the fluid level is still at the hot mark....shouldnt it be at the cool mark?