I think the tranny is probaby toasted!

[LawfullyChaotic]

Due to neglectance, the car has ODO of over 100k miles without transmission oil change. Now there's a slight delay between the 3rd and 4th shift. Does that necessarily means the transmission needs a rebuilt? Or just change the oil w/filter?

 

[andyw]

So are you saying it's been running about in 3rd gear for 100,000 miles.

 

[LawfullyChaotic]

So are you saying it's been running about in 3rd gear for 100,000 miles.

No, the car's transmission ran fine until very recently without oil change, it struggles to shift to the 4th gear until the engine is close to 4000rpm when running at cold start.

 

[adrianr]

Does it change ok when up to temp?

i thought auto boxes hold themselves in lower gear top get up to temp faster - my Previa used to ?

Might be wrong though.

 

[LawfullyChaotic]

Does it change ok when up to temp?

i thought auto boxes hold themselves in lower gear top get up to temp faster - my Previa used to ?

Might be wrong though.

It shifts perfect in normal operation temp, the problem is only when the vehicle is cold.

 

[uHu]

No, the car's transmission ran fine until very recently without oil change, it struggles to shift to the 4th gear until the engine is close to 4000rpm when running at cold start.

If you read the manual, you will find that this is normal behaviour.
The TC will not go into lock-up until the coolant has reached a certain temperature (was it 60 or 65 deg C?), that is what feels like not going into the top gear.
Running with open TC generates more heat, and helps the engine getting up to operating temperature (where it is more efficient, and lubrication works better). As the ATF flows through the bottom part of the main radiator, the engine coolant and ATF keeps the same temperature, more or less.

 

[Brian the Sn@il]

Maybe also the recent cold weather also makes it more noiciable ?

GET the Oil Changed NOW !!!

 

[rnjacobson]

probly need to take it in to auto trans service place to get adjustments made on the transmission etc

 

[LawfullyChaotic]

UPDATE:

-Changed the transmission fluid today, the old fluid is almost pitch black with a burned smell! Strangely, the filter was absolutely clean (almost AS new) and no signs of metal flakes. Am I still in the safe zone?

 

[adrianr]

I think id be inclined to run it for a hundred miles or so and change it again - its impossible to get all the fluid all through and out. The ATF us definitely past its best in the condition you describe.

 

[uHu]

UPDATE:
-Changed the transmission fluid today, the old fluid is almost pitch black with a burned smell! Strangely, the filter was absolutely clean (almost AS new) and no signs of metal flakes. Am I still in the safe zone?

How much fluid did you exchange?
When doing a drain-and-refill, you change only about a quarter of the fluid. If you do this three times, you have changed about half of the fluid, which is normally noticeable when it comes to gearshifts, given the condition of the atf as you describe it.
Otherwise, it sounds about normal to have black, burnt fluid after all your miles. Sounds like my fluid after only 100 k km. (That's on my 2000, with the 4-sp box. The newer 5-sp seems to be a bit easier on the fluid.)

Nothing on the magnets sounds good. And with nothing in the mesh your box is probably like new.
What year and month is it?