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Good evening. I'm searching for help on when my '05 Cobalt needs to have it's transmission flushed. It's not the SS, just the basic. I'm getting answers ranging from 30k-100k. I would really appreciate some help as even the dealerships give me different answers.

Thanks.
 

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Your owner's manual will say, with normal use, that the trans fluid is good for 100k miles
 

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Your owner's manual will say, with normal use, that the trans fluid is good for 100k miles
A bad idea in my opinion. I would do it every 30k miles at least. Especially if you do a lot of stop and go.
 

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I agree with the preventive maintenance advocates.
I'd rather pay for ATF every 3 years/30,000 miles than get a 2-3 grand trannie bill.
I would not run any fluid for 100,000 miles. Just as I wouldn't run Amsoil for 25K. Would they do that in an airplane?
What's the point? How much do you save? Stuff wears out.
 

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I agree with the preventive maintenance advocates.
I'd rather pay for ATF every 3 years/30,000 miles than get a 2-3 grand trannie bill.
I would not run any fluid for 100,000 miles. Just as I wouldn't run Amsoil for 25K. Would they do that in an airplane?
What's the point? How much do you save? Stuff wears out.
Yea, that's a big part of it - a real sensible, safe, minimum expenditure choice w/o going into it all.

That assumes ( under 'typical' normal operating conditions ) your desired 'average' life expectancy is approx. a little stronger than 8-10 years and 150 -160K.

'As needed' to 15k to 25k for more severe - or for extremely long term ownership.


A real useful add would be to throw in even just one extra somewhere between 5 -15 K ( one time deal ) and keep the time interval ( thereafter ) to 24 months ie 24 mo/30k - which ever comes first.

( I assume we are all assuming the pan will be dropped and it and the magnets will be cleaned when we say a 'complete' flush. )

Of course, Dex 6 and no joke, while it really, really should not matter on that one ( Dex6) - I really do prefer the GM supplied fluid - so far.
 

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( I assume we are all assuming the pan will be dropped and it and the magnets will be cleaned when we say a 'complete' flush. )

Of course, Dex 6 and no joke, while it really, really should not matter on that one ( Dex6) - I really do prefer the GM supplied fluid - so far.
The "pan dropped" part is CRITICAL... way too many fly by night "quickie lube" joints will just hook your car up to a machine which sucks the bad oil out while it pumps good oil in... This technique has never been endorsed by GM engineers. How it keeps the clean oil from mixing with the dirty oil in the pan escapes me and how it keeps the clean oil from mixing with the dirt in the pan also is a mystery to engineers everywhere.


You need to drop the plan and clean out any crap that is there. If accessible, you also need to replace the filter.
 

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The "pan dropped" part is CRITICAL... way too many fly by night "quickie lube" joints will just hook your car up to a machine which sucks the bad oil out while it pumps good oil in... This technique has never been endorsed by GM engineers. How it keeps the clean oil from mixing with the dirty oil in the pan escapes me and how it keeps the clean oil from mixing with the dirt in the pan also is a mystery to engineers everywhere.


You need to drop the plan and clean out any crap that is there. If accessible, you also need to replace the filter.
YEP.

(Although there is a type of 'logic' to it - the fluid more often than not ( assuming nominal conditions ) contains most of the wear particles and a slight 'overflush' can have a useful 'cleansing' effect.)

(Also many times, the add pack or a big part of it has been 'used up' - needs renewing.)

Anyway, back to the 'YEP' - especially when one realizes that the 'filter' is really a 'safety strainer' and 'used' ATF is essentially a cutting oil - that you're circulating thru the unit - all the time.

I don't want to go too far into best practice AT/ATF maintenance - requires too much typing to do it justice - too many variables.

Damn clever how ( industry wide ) useless non filtration is provided - and additive stripping would occur on most fluids used if it was.

( Ford does have some interesting high quality bypass filtration 'across' the cooler on their big stuff )

Technically speaking, there are many ways , schedules and strategies to maintaining an AT 'well'.

Depending on this and that, dropping and clearing/cleaning the pan and magnets ( when equipped ) is almost always at least as important and in some cases more important than getting a full 100% fluid exchange.

Go long enough and 'hard' enough and it's definite.

Use and user/duty cycles blow this topic way up for complete accuracy.

That said, there are 'programs' where a full fluid flush can be used - w/o a pan service - as an adjunct - never as a full substitution.

One of the cheapest, most cost effective and best things a young person can do to prolong AT life is to get a full 'service' done ( ie pan drop and clean plus full fluid ) between 5 -15k - regardless of what comes after.

If you have the resources to spend, on some, doing more than that is useful as well.

On 'mine' - really S/O - I drive stick - 'only' I do this at 5,10, 15 - then whatever - 12mo./15k for stuff I 'like' up to 24mo/30k for things I wouldn't mind going over a cliff.

'Shedding' - from break in - is just unreal between 0 - 15k.

If you get even just one extra one in early, the longterm positive effects are almost as unreal as well.
 
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