Transmission: Drain Vs. Flush

[Jesda]

My Mobil 1 ATF is starting to look a bit dirty after a year and 15,000 miles, probably due to the high running temps before I replaced the thermostat. I cannot afford a $200 machine flush now (but I will this winter). Would draining as much fluid as I can by removing the bolt on the pan then refilling get me by until January? Or is this a waste of time?

Either way, I need to wait until winter to get this done professionally.

Thanks!-Jesda

[qship96]

do it! draining it overnight will allow 3-6 quarts to be replaced out of the aprox.11 total quarts in the system,and replenish enough to significantly improve the quality of the fluid.get a full flush later as you intended.

[psychic_mechanic]

Q45Tech had a post on this and using a stopwatch to drain the pan every 2 minutes I think (search it) based on the amount of fluid the pump moves at idle.

I'd flush with regular ATF than repeat with Mobil1.

[QE86]

Q45Tech had a post on this and using a stopwatch to drain the pan every 2 minutes I think (search it) based on the amount of fluid the pump moves at idle.

I'd flush with regular ATF than repeat with Mobil1.

Hey psychic_mechanic,

Do you know where is a good place to do the transmittion flush?? I am in So Cal just wanna know if there is any shop you will recommend. Thanks

[Q45tech]

Remember the cooler drain return line DOESN'T go to the PAN FIRST, it feeds the critical rear planetary gears then dribbles into to the pan.

Why a restricted cooler/line takes out the rear planetary first!

Never try to drain and refill while the engine/transmission running without using an external membrane machine to maintain ATF pressure on rear planetary.

Simple pan drain repeated frequently enough will be 75% or better equivalent of a machine exchange without the circulating solvent flush..

If you are methodical and time the pan drain and run intervals with a stop watch, you can probably safely do a circulating chemical flush and fluid exchange with ATF without a machine?

Just reference the new ATF color on a white paper towel and keep changing [draining from pan] till the colors match perfectly.

Many times you will see that even with a machine flush and 14 quarts the colors don't match so another 14 quart flush is need for perfection a week later.............due to internal cross contamination [seal leaks].

Once you get it perfect annual flushes will keep it that way.

A perfect pump will move 4 quarts per minute at warm idle in park thru the cooler lines..........that is almost like measuring human blood pressure except the volume goes down [as the mechanical pump is fixed].

Owners can trash a transmission at 120k [or less] or extend its life to 200,000 + miles. Every day you don't have to spend $3,000 to replace one is a good day! Spending $200 per year on average on maintenance sure seems cheap compared to the replacement cost.

[elwesso]

Jes... Id say your best bet would be to do a drain and refill every 3-4 days for a couple weeks...

If your going to drain/refill then do a machine flush later in the year conventional might be ok, not sure how it would mix with M1.....?

However I would like to try that drain/refill method of running the engine exactly for 2 mins...

EDIT: As long as your fluid isnt spent (15k should be ok for m1??) i dont think waiting would hurt you.....

[psychic_mechanic]

I'd recomend a dealership, the quality of the fluid makes a big difference. These transmission shops get their stuff from the lowest bidder, so unless you bring them Mobil 1 (ask for discount because they are not supplying fluid) I would get it done at a place that will use factory spec (nissan/infiniti) fluid.

I do most of my stuff out of my garage and messy things at the hobby shop on base for $1 an hour or so. (more for lift)

[Jesda]

I've got a performance shop that charges an arm and leg but is exceptionally thorough, so I'll have them do the M1 flush again this winter and do my own drain/fill this fall just to get by (the fluid isnt bad yet, just not perfect).

Thanks everyone for all the valuable info! (God I love NICO)

[QE86]

I'd recomend a dealership, the quality of the fluid makes a big difference. These transmission shops get their stuff from the lowest bidder, so unless you bring them Mobil 1 (ask for discount because they are not supplying fluid) I would get it done at a place that will use factory spec (nissan/infiniti) fluid.

I do most of my stuff out of my garage and messy things at the hobby shop on base for $1 an hour or so. (more for lift)

I am going to bring Mobil 1 myself I guess. But from the information I got from the posts previously I would flush the trans once with normal Trans fluid and flush again with Mobil1 ATF.....I dont want to go dealership bcoz they will charge me an arm for doing those...is there any shops you know that is good???

Thanks

[texasoil]

Dealers often/usually use even cheaper oils than oil change places. They DO NOT use OEM stuff unless it is a specialpart number fluid--like some ATF's for MBZ now.