I did a service on my 1990 Toyota pickup. Its a 22re 4x4 with auto trans. I just did the service not a flush. My old fluid was black. What is that I sign of? I've never seen trans fluid turn black.

 

Its a sign you should have changed it a long time ago.

Also...if its not shifting weird or anything....leave it alone.

Dont even think about a auto trans if its runnung good.

The mere thought alone could cause one to blow.

 

Why would it make it blow. Black fluid can't be good for it right??

 

The trans blowing by thinking about it was a metaphor for the delicate nature of transmissions in a modern world.

Black trans fluid....is just really dirty fluid. It didnt smell burned up did it?

If your trans is shifting good...do nothing more than change the fluid and filter.

Automatics are tempermental. If they think you are worried about them...they will act up just to spite you.

 

It smelled fine. I just drained the fluid, then dropped the pan, the changed the filer. That's all I did. I was just wondering about it being black. The truck has 280k miles and was wondering reckon that might have been original fluid?

 

When I was looking at 2nd gen 4runners to buy, I encountered several that had black ATF in them. All those that I saw still seemed to shift OK, but it was enough to put me off, even though they appeared well kept otherwise.
I ended up finding a 5 speed I liked and I'm very glad to have it.

 

Black fluid is just like I said really really dirty. With aluminum residue...clutch material....and all the things inside that wear over time..they contaminate the fluid and it gets dirty. Theres a good chance that it was never changed. I say auto trans fluid changes are one of the biggest neglected items on cars. That and coolant flushes.

Unfortunately..I've had more than my share of auto trans nightmares. (ford mach1) Im of the shool of leave em alone. Ill do a fluid change about every 2 years or 20k. Id never power flush.

I think of them as a magic box. Open the box...the magic comes out. Only a certified magician can put the magic back.

Best upgrade you can do...bypass factory trans cooler and get a big arse stacked plate trans cooler. Buggest mofo you can mount in a safe place....and with toyota 4x4's theres a ton of room.

I was told the cooler it runs the better. Cooler trans last longer and fluid last longer. Warmer it runs...dramaticaly scales for the worse.

 

Your opening up a can of worms. its black because its old and burnt. Maybe the PO did some towing or hauling with it. Who knows but the whatever the reason the damage is done. The last thing you want to do is a flush. Your pushing it with the filter change. Why you ask? Well the auto tranny relies on "grit" in the fluid to make a crisp shift. Don't believe me? Rub some brand new ATF between your fingers and you'll feel the grit. By flushing out the old black ATF your removing alot of the build up grit and your tranny may start slipping a lot. Someone once told me you can pour some sand in the dipstick tube to buy some extra life in an auto tranny. good luck

 

I have successfully rebuilt more than a couple automatic trannys, although no Toyota made ones yet, and I can say for certain that no properly functioning auto tranny requires any 'grit' in its fluid in order to function correctly, and further, that no new ATF has got any 'grit' in its formula.
One of the best things that can be done to increase the life of auto trannys is to install an inline filter such as the Magnefine.
It may well be true that an already thrashed tranny is best left alone if some small additional service is to be got from it.
I have seen an improvement in a couple near dead trannys when old Type F fluid was changed into them. Type F is basicly a simple hydraulic oil with none of the friction modifier additives that more modern fluids contain.

 

While I do subscribe to the notion that automatics might fail shortly after a fluid change, I am not for a minute going to believe it's because there's sand in there. Putting sand down the dipstick might let you unload a car on some unsuspecting sucker, but would not be the moral choice.

Toyota specifies ATF in the power steering system of these old trucks. How would "grit" help in that situation?

 

Millball what do you think friction modifier is? its a fine grit. Your contradicting yourself.

 

The friction modifiers make the oil slicker, not less so.
That's why changing to the Type F may have some helpful effect in some trannys, sometimes, at least briefly.
The oil with no friction modifiers is less 'oily'.

The History of ATF:

http://www.lifeautomotive.com/pdfs/history_of_atf.pdf

 

I highly doubt friction modifier is actually a solid particle that would cause wearing to transmission components.

There is anecdotal evidence that a tranny can fail after a long-overdue fluid change. I've heard that it is smart to ease the fluid into a clean state. So if you trans hold 6 quarts, drain out 2 and refill with 2 fresh quarts. Drive for a while, repeat. That way you prevent a shock to the system, maybe causing deposits to suddenly let go.

An inline filter in the ATF cooling circuit is always a good idea too. Check out Magnefine.

 

I was told at AutoZone to use dex merc for my truck. I changed it a month ago and its doing great

 

lol I hate, am terrified of and have a huge respect for automatic transmissions!