How to change the transmission fluid?

I have a 1991 Camry 4cyl Auto, 97Km. So far I always had the shop change the transmission fluid. When ever I checked the level it was always a little above the max. The mechanic said that this is the way it suppose to be. From reading the posts on this NG I realized that the increased pressure can damage the transmission. I have never seen the ATF level below the HOT region when the engine was cold, although the hot level was close to the MAX mark (and not way above it) when the transmission was hot. I would be thankful if someone could give me some tips to avoid overfilling. Since it is much easier to add than remove, is it safe to add fluid up to the COLD region, drive the car and then check if more fluid should be added?

Another important issue that I learned in this NG, is the need to change the differential fluid. When I confronted my mechanic about it, he said that there is no reason to replace it. When it was drained it was black and thick. During the last 5 years I changed the ATF every 15K or less, because it always appeared a little dark - is it possible that the dark differential fluid got mixed with the trans fluid? For 5 years, everytime I change my ATF, the mechanic says that my trans about to die, although it never gave me any problem.

Reply to
bauz
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Cars are not designed to suddenly give you problems because you have a slightly over-filled transmission. To get into trouble, requires a drastic over-fill.

- with automatic transmissions, check them hot (after 15 miles or 25ks of driving) as long as the oil level is within the min-max limits, (preferabley as close to max as possible) it's fine If its *slightly* overfull ( less than 1/8" or 3mm above the max mark) there is no danger. Make sure the car is on a level surface when checking the dipstick.

He's refering to older designed diffs on some rear-wheel drive cars (Fords, GM stuff). The prevailing logic back then was that it was better not to open the diff to contamination, plus they were mechanically removed from the gearbox and thus were not susceptible to oil-contamination from the gearbox (auto or manual),...not so today with transaxles in front wheel drive cars. So the diff should be manitained as indicated in the driver's h/book or a w/shop manual.

When it was drained it was black

It shouldn't be black,...it needed changing.

During the last 5 years I changed the ATF every 15K or less,

-that's a particularly short time interval.

Maybe.

Did he back up his claim by showing you ATF (from your car) which was discoloured and any metal from the auto filter or pan? If not, he was being less than honest.

Jason

Reply to
Jason James

The differential is to be changed with ATF fluid every 30000m . Have you had your trans pan dropped and filter changed, it is also 30000m change. Just fill the trans less and check it before you overfill it.

Reply to
m Ransley

snip

IF you had stayed around a little longer (a day or so), you would also have read a stern admonishment directed at the person who posted that rubbish (over filling causes transmission pressure rise).

This forum is not moderated by a Toyota technician and only a couple of the Users are employed Toyota technicians.

snip

What kind fluid is your mechanic installing into the final drive box? (differential).

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    - Philip
Reply to
Philip

Thank you all for posting your comments.

The fluid that the mechanic used for the transmission and the final drive box was Dextron III.

discoloured and any metal from the auto filter or pan?" He didn't show me any metal, but I was present while he drained it, and it was pretty brown.

have read a stern admonishment directed at the person who posted that rubbish (over filling causes transmission pressure rise)." I am relieved by knowing that a small over-filling should not cause any damage. Several posters put strong emphasis on filling less rather than overfilling. I am trying to prolong the life of the transmission, therefore I replaced the fluid more often when it was dark, and got concerned when I read about the (false) assumption about increased pressure. Since the last differential fluid change (and probably also the first) yield a very dark fluid, I would replace it again soon, and then go back to normal intervals of 30K.

Thanks! (BTW - I am new to posting on a NG and I hope I quoted other replies properly. Is there any guide for proper posting?)

Reply to
bauz

bauz wrote: snip

There may be an avalanche of replies to this question.

In your case, put a space (line) between your reply and the paragraph you are responding to.

As for top vs. bottom vs. interspersed posting, once a top or bottom posting precedent is established, stay with that format. Preserves readability. Try to resist "interspersed" posting.

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    - Philip
Reply to
Philip

I found this good article:

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Reply to
bauz

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