Is color an indicator of ATF condition?

[SecondMonkey]

I have a Jeep Cherokee with an AW4 transmission. At over 200k, I like to keep all the fluids as clean as possible. I generally drain the transmission pan (4 quarts out of 8) at every other oil change. (3k OCI) I just changed it again today, and even though I change it all the time, the ATF still seems quite dark to me, compared to the new stuff. (Dexron III)

So my question is, is ATF color an indicator of it's condition? Should I keep changing half the ATF until the color looks closer to new, or am I just wasting my time?

 

[CharBaby]

Well, it seems like changing your ATF every 6000 miles has worked very well for you although, most people would think that it's overkill. Color is only a small portion of what is going on with the ATF, usually at much higher mileage though. I've seen factory installed ATF still looks red at 50,000-60,000 miles. It puzzles me to say the least. If your is darkening by 6000 miles, I just think that it's because your mixing with the older stuff but it too puzzles me! Have you dropped the pan and changed the filter/screen? If not, maybe the pan could use a good cleaning and a new filter/screen wouldn't hurt either. Does the tranny still shift nicely?(The way that you expect it to?)

 

[Whitewolf]

Color isn't a very good indicator. Part of the ATF function is to keep dirt dispersed in the fluid rater than fro it to settle out somewhere where you don't want it. Some transmissions that use ,for instance, carbon fiber materials can make the fluid black in quite a short amount of time.
Color can sometimes help though particularly when coupled with smell (as long as you know what the fluid smells like in the first place).

 

[gonesurfing]

Does the ATF smell burnt despite changing it? Is it slipping?

What I've found in a couple high mileage transmissions, is the pan surface collects a lot of crud composed of burnt ATF and worn friction material. This black crud may be getting recirculated in your clean ATF, turning it dark. Drop the pan, change the filter, clean the pan with brake cleaner, and reassemble with a new gasket.

 

[unDummy]

Make sure that your ATF cooler is working. If partially clogged, or rendered inefective by any means(leaves dirt pinched hoses....), you could be baking your new ATF.

With a 6k ATF partial change interval, it should always look pretty good. Take gonesurfing's recommendation. Time to drop the pan for some cleaning. Another option is to install apermacool/magnefine ATF filtration.

If your ATF cooler is working, and pan is clean, then your ATF choice isn't cutting it. I would upgrade to a better fluid. A synth blend(like Mercon-V, DexVI, or some univeral multi fluids) would be a smart move without breaking the budget. A full $ynth should be considered if vehicle sees ANY type of work, but not really needed at this mileage level.

If you want to stick with cheapo dex/merc, consider a bottle of lubegard or smartblend red.

6k partial ATf changes is not a waste of time.

 

[zrxkawboy]

If it were mine, I'd do a UOA out of curiosity.

 

[SecondMonkey]

Hmm, well, here's some pics of the fluids so you can see what I'm talking about.

As you can see, it's quite dark even though I change it so much. I don't think it really smells burnt, but it definately smells stronger than the new stuff. As far as I can tell the cooler is working OK, but even if it didn't, I don't think I would be burning the fluid, because 95% of my driving is less than 15 miles round trip.

As far as the pan, no, I haven't taken it off, and for now, I'd like to just leave well enough alone. I don't want to end up finding or making a bigger problem.

But even if it was dirty, shouldn't it be getting cleaned out pretty well by now? Should I just keep draining the pan every 100 miles or so until something cleaner comes out?

BTW - the transmission still shifts like new, and I'm using Chevron ATF.

 

[crashz]

Ugh - thats pretty ugly!

I was thinking dark, but still fairly clear. That looks a little milky. MAybe test it? I looks to me that you might have coolant mixing with the tranny fluid, or water getting in.

 

[SecondMonkey]

Originally Posted By: crashz
That looks a little milky. MAybe test it? I looks to me that you might have coolant mixing with the tranny fluid, or water getting in.


If that was the case, would the water settle to the bottom after a while in the empty 2 liter bottles I keep the old fluid in? Unfortunately a UOA isn't in the budget right now...

 

[Whitewolf]

It only takes just over 0.1% to start to make the fluid look milky. At that level the water will not drop out. You really should get a UOA. It may not be in the budget but if there is something wrong it could turn out to be a bargin!

 

[gonesurfing]

Strange... dark ATF usually has a purple tint to it, not brown. I can't remember if the AW-4 has an external or combined ATF cooler. If it is built-in the radiator, I back Whitewolf, and recommend a UOA. If coolant were leaking in, it may react with the air in the ATF rusting your lines. The good news is that if it is water and you're not experiencing shift problems, you may save the tranny by fixing the problem. If it's not water, you can focus on your ATF choice and properly cleaning the pan.

 

[PT1]

UOA definitely. Blackstone $22

 

[SecondMonkey]

If there was a very small amount of water getting in, just how bad would that be for the transmission? I'm not losing any coolant or anything, so if there is water in there, it's not much. I do have an external cooler I might install, though I was saving that for another project...

For now I think I'm just going to keep changing it very frequently until I see a color difference. I mean, it's got to run out of dirt eventually, right? I have two cases of ATF already, so it won't cost me anything.

BTW - Chevron ATF isn't a bad fluid, is it?

 

[Whitewolf]

At 0.1% the water will start to react with the FM and produce acidic by-products that can change the friction characteristics.
Water can also react with other ATF components causing additive drop out. At higher levels of contamination the friction materials can sustain irriversable damage.

 

[unDummy]

UOA is a must here.
Also, change your ATF at EVERY oil change.
Dropping the pan is a must for cleaning and filter replacement.
Fluid starvation can cause similar 'baking' of the ATF. Do NOT leave well enough alone.

I've seen plenty of roasted ATF. Check the flow through your ATF cooler. And, how are you checking your ATF level?

I'm not worried about water here. It'd be more noticeable. I do worry about antifreeze. You don't need to see the level to drop to have enough contamination to kill a tranny quickly. How long will you be able to save the tranny with those maintenance intervals?

Chevron ATF is good enough.

 

[Whitewolf]

I'm really curious to see what your UOA reveals. If anything!
Full ICP
KV 100C
KV40C
TAN
and in this case KF water
Is my minimum, if that's any help. I'm sure that's probably what you have done already.

 

[SecondMonkey]

Unfortunately I just don't have any spare cash for a UOA right now. Still paying off $30k in medical bills from last year.

The only reason I'm changing the fluid is because for some reason I have two cases of it in the garage...and I can't even remember why I bought them.

For now I'm just going to keep changing it every 100 miles or so, and compare each sample, to see if it's getting any cleaner looking.

How do I check the flow through the ATF cooler? Just disconnect the line and start it up?

Another thing - I tend to be a little hard on the vehicle. Most starts are WOT at 5000 RPM...with some tire squeeling here and there. Might that be what's darkening my fluid? She still really gets up and goes pretty well for an old jeep.

And - I want to make it clear, it still shifts PERFECTLY.

 

[mjoekingz28]

I use this method for Type F in my power steering. When started it was similar to the first picture. Now, 10-15 times at 8oz each....I believe 3-5 quarts of new supertech fluid, it is now difficult to tell whether the fluid is used or new. It was a hot day and I was out of drink and it looked just like some cherry koolaid.


btw, this is over a 2 month period of about 1000 miles.

 

[Hillbastard]

Why ask for advice then blatantly refuse it?

Transmissions are forced to pass 100% of their fluid through the filter (unlike most engines) and I would say you need one, and especialy a rag to the inside of the pan.

 

[Hillbastard]

I would guess there's a inch of mud in that sucker.