"Sealed" Auto Tranny Service Interval

[Applejack]

Didn't see any post directly dealing with this and didn't want to continue to jack anyone's threads so.........
Toyota claims a 100k transmission flush, is the earliest you'd want to change the ATF on the late model Taco's with the fully sealed automatic. Some have told me "Change it early, change it often." but the dealer urges me not to do it, for fear that the tranny may slip, under load. Anyone here change theirs earlier? What was the effect?
Again, this is only for the "fully sealed" autos. No dipsticks, no nothin'.

 

[keezer36]

I have some 25k ago.
After taking a sample of the fluid and noticing how dark it was, usually an indication of the fluid being overheated. I figured the only thing that would slip is a little money from my wallet.
There was no effect from doing this. The truck performed well before and after the change.
I've since travelled across country and climbed in excess of 8k feet in 110 degree heat loaded down, no slipping. I've also towed 8.5k pounds for 10 miles with some small hills with no effect, at least not on the tranny. Brake performance was another matter altogether.
I will not concern myself with the tranny again. I've a '98 BMW that has a sealed tranny with well over 100k miles and it has performed flawlessly. I think they've got this technology down.

 

[Jacket]

Is there a different interval recommendation in the maint. manual for towing or "hard use." I seem to recall that 100k was for "normal use", but Toyota recommended something else for towing. I guess I could check my manual...

 

[BrandX]

are you going to try it yourself or take it to the dealer?

 

[jbs]

I had mine changed in my 06 4Runner at about 35k. I did this only b/c when adding a transmission cooler, the few tablespoons I caught in a cup had some light metal shavings. I was not sure if they came out with the fluid, or washed off the frame with the drips. My dealer was having a special where they did not charge extra for the WS fluid (normally ~$10/qt). I sent a sample to Blackstone labs for analysis so if it was a transmission problem, I'd have evidence of it b/f the warranty expired. The fluid looked new and the analysis looked good:

I have towed my adventure trailer a good bit over the last year and spent a fair amount of time in 4Lo offroad, but most of the miles on the vehicle are highway miles. In retrospect I would have waited until 75k or so (still not the recommended 100k). I've never heard of issues from changing it early. I have heard that once a transmission starts to go (slip, clunk, etc), changing the fluid can hasten its demise.

The procedure for changing the fluid is a bit of a pain, but still something I would normally do myself. (http://www.lcool.org/technical/100_series/auto_fluid/auto.htm). In this case, the dealer flush only cost me about $40 more than the fluid alone, so I had them do it.

broc

 

[Overland Hadley]

I have heard that once a transmission starts to go (slip, clunk, etc), changing the fluid can hasten its demise.

Why would that be?

 

[SOAZ]

Why would that be?

I've heard it too, but I think its an old wives tale. Kinda like, if its already going, don't mess with it. Just hopes it holds as long as possible.

I wonder if there is any truth to it. I for one, change it often.

 

[jbs]

I've heard it too, but I think its an old wives tale. Kinda like, if its already going, don't mess with it. Just hopes it holds as long as possible.

I wonder if there is any truth to it. I for one, change it often.

The reason I heard is that the contaminants in the dirty fluid are needed to provide friction in the worn transmission. Perhaps it is indeed an old wives' tale. I mentioned it only in counterpoint to the claim that changing the fluid to soon could cause problems. As in, I've never heard that one.