Should I flush my tranny fluid? Pics

[yukon]

Recently had a chance to get some transmission fluid all over me (installing my tranny cooler) and was lucky enough to catch some in a cup. Now I've wanted to do a flush of the fluid in my 99 limited for some time now, and have read that some say you can mess things up if your transmission has dirty fluid already. So here's what I have, what say the masses, should I go ahead and flush, or hold on to what I have?

Old in a cup

New and Old

More new and old

(sorry for the relativly crappy pics, its hard than you think to get good pictures of this stuff)

I have 120k on the clock, un-known if a flush has been done before. The fluid smells like I would expect old stuff to smell like...

What say the masses? Any experts on here that might have some advice?

 

[pillguy]

I am very interested in this topic as I have am planning a transmission cooler install to avoid the "S-milkshake"

 

[raydouble]

I would think a drain and fill is in order. I did my first at 90,000 miles. If you tow anything or load down the rig heavy, you might want to skip and go straight for the filter and flush. Looks old and burnt enough to justify it.

 

[Duane]

Well I went through this topic when I had my transmission flushed on my 96 runner with the 2.7 litre I4 engine..different tranny than behind the 3.4 I think. No filter in mine just a screen.

I ended up with problems and my fluid was better looking than yours. What i think happened was the garage I took it to put something else in or maybe the seal conditioner/additives they like using ended up binding my throttle via a spool valve in the tranny valve body. We tried a synthetic after that and still problem with a binding throttle, a hard shift or delay upshifting as well.
Ended up researching that the local Toyota dealership uses an Esso Dexron III fluid..same as the local Minute Lube so I ended up going to the minute lube for a flush to get out what ever the local garage had put in there and it fixed my problem with the binding throttle cable to the transmission. A flush at the Minute lube was about the same price as the service at the dealership. 13 litres compared to 3 litres
I talked to 2 dealerships... both preferred the drain out and top up method as opposed to a flush. 1 dealer said if the fluid looked bad enough they would chose a flush over the drain and top up/blend method. Dealerships here recommend the tranny fluid service every 30,000 miles and Toyota schedule up here says every 15,000 miles.
My 2 cents would be that it looks dark enough that I would go the flush route. A transmission is too expensive to run dirty fluid in it. Trying to blend it clean by replacing a 1/4 of the fluid at a time will take several times to clean it up.
A sort of nice idea is to drop the pan and clean out the gunk as well first because the concern about flushing is stirring up the sludge and pushing it through the rest of the system.
See what the masses suggest and then pick your route!

 

[raydouble]

Well I went through this topic when I had my transmission flushed on my 96 runner with the 2.7 litre I4 engine..different tranny than behind the 3.4 I think. No filter in mine just a screen.

The filter in the V6 trans also has that screen style filter. I have heard of a lot people just pulling them out spraying them out with brakleen, letting them dry and using them again with no issues.
As long as they are cleaned and not damaged, there should be no issue reusing them.

The pan can be a pain in the ass....the gasket is a red Toyota FIPG(forminplacegasket) and can be difficult to separate the factory seal.

I flushed and filled mine to make myself feel better about delaying the actual filter flush and fill.....so if you have the funds and the way, with the fluid looking like mine smelled, I'd do it all up and start fresh.