To Flush or not to Flush

[Project FJ80]

I need my transmission fluid changed. I have 330,000 miles.
Ive been towing heavly with it alot. Should I have it flushed with this amount of miles?
or just drop the fluid change the filter and refill?

reason I asked, I had my mopar flushed, and then it stopped shifting. I had to get a rebuilt kit for it which left me with out a car untill I could pull the tranny, and pay to get it rebuilt.

I cant be with out my Cruiser

 

[LandCruiserPhil]

I would do just a drain and fill .... ~3.5 quarts

 

[Tools R Us]

Remove drain plug, replace, refill with ~a gallon of ATF, done until the next oil change.

 

[wspastorbryan]

I just dropped my pan, did the filter filled it up with 4 quarts and took it around for a loop around the neighborhood and it shifted weird. No problems before, just a dented pan. From park it would go up to about 2000 rpms then shift pretty hard. Not hijacking hopefully! That's my experience thus far...

 

[Project FJ80]

Thanks, Will do.


What type of ATF did you use?

 

[Tools R Us]

Thanks, Will do.


What type of ATF did you use?

The red kind!

The Dextron III label is no longer used, now it says something like suitable for older GM trans?

 

[Tools R Us]

I just dropped my pan, did the filter filled it up with 4 quarts and took it around for a loop around the neighborhood and it shifted weird. No problems before, just a dented pan. From park it would go up to about 2000 rpms then shift pretty hard. Not hijacking hopefully! That's my experience thus far...

Never had one do that. Did you let it idle for a bit, allow the air to work it's way out?

 

[hj60]

I flushed mine at ~250k miles.
Didn't have problems before that, other than brown fluid.
Didn't have any problems afterward, either.
I did use BG's trans flush and conditioner.
Getting ready to just do a drain and fill nearly 4 years later.
Have another BG kit sitting by.
I use Valvoline MaxLife ATF. Mainly because we stock it, so it's dirt cheap to me.
At somewhere in the neighborhood of 350k miles, my tranny's beginning to show its age, though.

As to the needing to rev it up before it'll grab, I've had that happen when I accidentally left a trans low on fluid.
A good practice is to let it run for about 10 minutes after you fill it so the fluid can get warm and air bleed.
Then shift it through all the gears, letting it sit a second in each one.
Put it back in park and check the level. If it's between the top cold mark and bottom hot mark, take it for a long enough drive it spend a minute or 2 in OD with the converter locked up.
Then park it and recheck your fluid.
Unless you've been pulling a trailer full of bricks up to Bumblebee, I tend to leave the fluid at the lowest hot mark, or slightly above.
Your fluid isn't gettng truly hot just taking a 10 minute spin on city roads.

 

[wspastorbryan]

Never had one do that. Did you let it idle for a bit, allow the air to work it's way out?

No. I didn't get above 15 mph though. I just went out and checked the fluid and it looks like the air should be out because the levels dropped significantly. I used Castrol because I didn't feel like researching the best fluid and I just wanted to get her going. About to go on a ride to see. I'll let her idle for a while though.

 

[wspastorbryan]

Here's my findings thus far. I have a a343f and after a pan drop and filter change I put in 4 quarts, no good, 4.5, no good, 5 - no slipping, runs great, but reads at the cold line when it is completely warmed up. It's been reading all over the dipstick.