Dirty ATF?

Messages
3,297
Location
West Michigan
On our 3.5L Olds Aurora I replaced the ATF (Dex3 spec) back in the spring of this year and a couple thousand miles ago (probably 2-3k) with Napa Dex/Merc fluid. Did the pan/filter method which supposedly on these trans does get the vast majority of fluid- spec is 7.4qts capacity and it took 7.0qts to refill. Checked the dipstick yesterday and noted the fluid looked very dark, which I know does not really mean a thing with ATF but considering the low miles on the new fluid combined with the high miles on the old fluid I was wondering if its worth spending the $25+ on a UOA, if its better to just do another fluid exchange or maybe not worry about it at all. Trans seems to shift pretty good, certainly hasn't changed at all.
 
Messages
1,847
Location
Laramie, WY
Give it a try, I have done that pan drops with filter changes plenty of times, it replaces half the fluid in my cars and they went from brown to red and 40k miles later they are still red...I used Amsoil & Castrol Import ATFs though, so can't say much about the rest of the ATFs
 
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pbm

Messages
8,889
Location
New York
I would guess that your new fluid cleaned out some accumulated gook from the original 'extended' ATF interval. I would just do another fluid change (not a UOA) and call it good.
 
Messages
132
Location
United States
If it were me I'd change it again, 7qt of fluid is cheap enough for piece of mind that the tranny is not going to die from the dirt being dislodged/cleaned by the new fluid. You see that happen all the time.
 
Messages
5
Location
Northern Delaware
I have a old BMW (only 103k on clock) with the GM 4L30e auto transmission (it's a variant of the GM 4L60 found all over the place). Trans is S-L-O-W into reverse - count to 5, then it engages. Forward gears & shifting good, no slip, no bang. Fluid level is correct, color of fluid is a good red. I *think* previous owner changed the fluid, since color is good. People who are familiar say "reversing valve" in the body is sticky. I've been thinking of changing fluid, hoping that might will cure it, but, worry that it dirt dislodged might kill it instead. evanautumn's idea (practice?) of multiple fluid changes to flush-out the dirt makes sense to me, say fluid change #1 drive a few hundred miles, fluid change #2, wait a month, fluid change #3... This is strictly a weekend cruiser; I've been driving it with slow reverse for years (about 15,000 miles), figuring that it's just annoying, and when forward gears begin to go, that's soon enough to spend the $$ for a rebuild. Let it alone, multiple fluid changes?
 
Messages
1,462
Location
East Mountains, NM
A friend of mine used to own a transmission repair shop. He would not do fluid changes on trannies that had over 100k on them, unless the owner could verify that the fluid had been changed previously. Why? Because the accumulation of gunk that would be freed up by the fresh fluid would often cause problems, shortly after the change. I pointed out to him that folks with an unmaintained transmission most often thought to change fluid after a problem reared its ugly head......Thus the bad results. He agreed that this could also be a contributing factor to failure.
 
Messages
19,686
Location
Sunny Florida
Originally Posted By: Greasymechtech
Skip the UOA and repeat with full synth ATF, or at least a blend.
yep. I would probably try Maxlife. I am amazed you got 7 quarts out of it, that's a neat trick...
 
Messages
12,925
Location
Northern Kentucky
I would do a few more drain and fills starting with one now and then again in 1000 miles to get some more of the older spent fluid out. I would recommend Maxlife dex merc which is far superior to any of the mineral fluids available.
 
Messages
1,909
Location
Tracy, CA
GM 4-speed transaxles will drain quite a bit of fluid with just a pan and filter change. I'm with the others that recommended another fluid change a short distance down the road. Maybe the same time as the next few oil changes? A drain plug kit might not be a bad idea either.
 
Messages
1,555
Location
Oregon coast
Originally Posted By: 4wheeldog
A friend of mine ...would not do fluid changes on trannies that had over 100k on them, unless the owner could verify that the fluid had been changed previously. Why? Because the accumulation of gunk that would be freed up by the fresh fluid would often cause problems, shortly after the change.
Wrong. This my be his justification, but the reality is that he did not want to be the last person to touch it before it died of neglect/old age. Same as patching a bald tire, LIABILITY. Changing ATF in a properly functioning transmission, regardless of age, will only do good.
 
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Messages
1,847
Location
Laramie, WY
Originally Posted By: asand1
Originally Posted By: 4wheeldog
A friend of mine ...would not do fluid changes on trannies that had over 100k on them, unless the owner could verify that the fluid had been changed previously. Why? Because the accumulation of gunk that would be freed up by the fresh fluid would often cause problems, shortly after the change.
Wrong. This my be his justification, but the reality is that he did not want to be the last person to touch it before it died of neglect/old age. Same as patching a bald tire, LIABILITY. Changing ATF in a properly functioning transmission, regardless of age, will only do good.
I think so too, my two cars with straight brown fluid after a few D & R actually shift and drive perfectly now...
 
Messages
2,201
Location
socal
Originally Posted By: paulo57509
GM 4-speed transaxles will drain quite a bit of fluid with just a pan and filter change. I'm with the others that recommended another fluid change a short distance down the road. Maybe the same time as the next few oil changes? A drain plug kit might not be a bad idea either.
I agree. I installed a tranny pan w the drain plug on 2 of my vehicles and I do regular drain and refills with valvoline syn dex 3 compatible. Both vehicles work great
 
Messages
9,783
Location
Saskatoon canada
On transmissions without a drain I use a cheap transfer pump to do drain and fills. You can drain exactly a jug by using an empty one as a guide,then just replace with new fluid.
 
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