DIY Transmission fluid flush on 8 speed?

[Wild one]

Yes sir, sure will. And if I blow anything up I'll also post it.

Be very careful with the spring clip under the plastic cap,it has a habit of wanting to fly off,and can be a real b iatch to find if it takes off on you,lol. You have to slide the plastic retainer cap back on the line to get at the spring clip that actually locks the line together.

 

[Jeepwalker]

The short answer on "How?" ...is, a person/mechanic, etc, is starting/running the vehicle for a brief time (12-15 seconds??), AFTER the pan has been changed and new fluid put into the transmission (overfill if possible) ... and cooling lines have been unhooked and hose/s attached & routed into a bucket ..and pumping the old fluid out of the torque converter.

When started, the front oil pump (of the transmission) pumps new fluid from the pan into the torque converter and out the cooling lines (which have been diverted into a bucket), thereby displacing the 'old' fluid trapped inside the torque convert you can't drain ...it's being displaced *out* ...and into a bucket. The person stops as soon as the fluid runs 'clear'. It's almost a two-person job (one to start/stop vehicle, another to keep an eagle-eye on the fluid color). Again it all happens real quick, you're pumping fluid out of the transmission fast! It certainly isn't a job a dufus-minded person/owner/mechanic should undertake, and decides he wants to take a vape for 10 minutes!!

Well, I guess that wasn't a 'short answer' after all!

 

[DILLIGAF]

Orrrrrr.............You could just trade it in and not worry about it

The new trucks are all downgrades at this point.

 

[Atcer2018]

The short answer on "How?" ...is, a person/mechanic, etc, is starting/running the vehicle for a brief time (12-15 seconds??), AFTER the pan has been changed and new fluid put into the transmission (overfill if possible) ... and cooling lines have been unhooked and hose/s attached & routed into a bucket.

When started, the front oil pump (of the transmission) pumps new fluid from the pan into the torque converter and out the cooling lines (which you've diverted into a bucket), thereby displacing the 'old' fluid trapped inside the torque convert you can't drain ...it's being displaced *out* ...and into a bucket. The person stops as soon as the fluid runs 'clear'. It's almost a two-person job (one to start/stop vehicle, another to keep an eye on the fluid color). Again it all happens real quick, you're pumping fluid out of the transmission fast! It certainly isn't a job a dufus-minded person/owner/mechanic should undertake.

Exactly, it all happens real fast. Not sure how a person would keep the pan filled with fresh ATF even with a pressurized bug sprayer pump. I’d be worried about running it dry. Makes you miss the days when you could just pull the supply and return lines and stick the supply line into a gallon of ATF and be done with it in a minute.

 

[Jeepwalker]

Short answer is ...you don't! (keep up with fluid leaving). One strategy would be to overfill by 1.5qts ahead of time and dump a qt into a funnel as soon as the process starts. But ya can't get it in as fast as it's being pumped out. A guy can also stop part way through the process, quick added 2 qts, then quick have the expert helper restart-continue. Didn't seem long enough for the fluid to mix color. Regardless, I'm NOT recommending any course of action here!!! Just describing what other people do. You always have the wanna-be guy who says, "Yeah, yeah, don't worry, I get it!" then procedes to take a phone call from his kid, or decides to order a pizza, as the fluid is pumping out of his smoking tranny! Like the guy on the forum who'd been changing his tk's oil for years and it never occurred to him to check/verify the oil level AFTER doing it ...or between changes!!! WTF?!!!! (sorry if you're that guy, but THAT was classic! LOL).

Not sure how this will go with these ZF's. Hasn't anyone figured out how to add an F-ing dipstick to them yet?

OTOH...ever look at the connectors at some shops' Fluid Exchange Machines?!! That have been sitting or dragged on the shop floor or the dirty cup on the side of the machine? Not really 'cleaned' in maybe years? After I saw the hose connectors on one machine I never had my tranny fluid 'exchanged' by a shop again.

For most guys...better just to follow the normal change instructions to a T.

 

[Scottly]

The new trucks are all downgrades at this point.

I think once outside of the factory warranty period, I'd agree, because of the cost of maintenance and the questionable long-term reliability. But to someone who trades when the warranty is up, the new ones, as a whole, really don't experience issues, for the most part. Sure...there are problems. Example: The hydraulic roller lifters on the 2019-forward Cummins engine. I'll never see the mileage it will take to encounter that problem (100K++), so I really don't care. I'm old, lazy, and have a pocket full of money, so I let other people worry about the breakdowns. I jump into my other truck and keep going, so I really don't care.

 

[Jeepwalker]

I'm old, lazy, and have a pocket full of money, so I let other people worry about the breakdowns.

I love it!!

 

[DILLIGAF]

I did become mortgage free at 38 by trading in vehicles every 3 years

And now that I could literally go buy a TRX cash I rather spend it on a new acreage / shop and tools. ect.

I like my old sh!tboxes.

Once I hit 55-60 ill probbaly start leasing cars as I wont be able to move do to my disabilities... lol..

When I see all my young friends blow 100K on a truck while living in an apartment like a peasant I laugh.

 

[Atcer2018]

Short answer is ...you don't! (keep up with fluid leaving). One strategy would be to overfill by 1.5qts ahead of time and dump a qt into a funnel as soon as the process starts. But ya can't get it in as fast as it's being pumped out. A guy can also stop part way through the process, quick added 2 qts, then quick have the expert helper restart-continue. Didn't seem long enough for the fluid to mix color. Regardless, I'm NOT recommending any course of action here!!! Just describing what other people do. You always have the wanna-be guy who says, "Yeah, yeah, don't worry, I get it!" then procedes to take a phone call from his kid, or decides to order a pizza, as the fluid is pumping out of his smoking tranny! Like the guy on the forum who'd been changing his tk's oil for years and it never occurred to him to check/verify the oil level AFTER doing it ...or between changes!!! WTF?!!!! (sorry if you're that guy, but THAT was classic! LOL).

Not sure how this will go with these ZF's. Hasn't anyone figured out how to add an F-ing dipstick to them yet?

OTOH...ever look at the connectors at some shops' Fluid Exchange Machines?!! That have been sitting or dragged on the shop floor or the dirty cup on the side of the machine? Not really 'cleaned' in maybe years? After I saw the hose connectors on one machine I never had my tranny fluid 'exchanged' by a shop again.

For most guys...better just to follow the normal change instructions to a T.

lol won’t work with the ZF. Can’t overfill the pan and the fill hole is under the truck at the top of the transmission and above the exhaust.

 

[Wild one]

Dang it! I guess it wouldn't be as simple as it was on my 3rd gen. LOL! nevermind. I'll stick with the drain and fills. Still getting that thermo bypass. Thanks.

You could disconnect both cooler lines by the rad and blow out the cooler with about 25 to 30 psi of air,that'd give you a head start on the drain and fills,just don't carried away with the air pressure

 

[caulk04]

A case study in over thinking, I like it

My bypass can be found at this link and for now the new aluminum TMU plug is available directly from me for $40 shipped. PayPal Venmo or Zelle to [email protected]

The plug is optional and you can read about both extensively around here

 

[stenerson]

A case study in over thinking, I like it

My bypass can be found at this link and for now the new aluminum TMU plug is available directly from me for $40 shipped. PayPal Venmo or Zelle to [email protected]

The plug is optional and you can read about both extensively around here

Yep, I plan on getting both, thanks.

 

[Scottly]

I did become mortgage free at 38 by trading in vehicles every 3 years

And now that I could literally go buy a TRX cash I rather spend it on a new acreage / shop and tools. ect.

I like my old sh!tboxes.

Once I hit 55-60 ill probbaly start leasing cars as I wont be able to move do to my disabilities... lol..

When I see all my young friends blow 100K on a truck while living in an apartment like a peasant I laugh.

Understood...I didn't get a pocket full of cash carrying a mortgage in my thirties, either....So good on ya for doing that. And don't lease...pay cash, negotiate correctly, and the difference between new and trade is much less than the money lost leasing (IMO). Besides, when ya don't lease, it's easier to keep it when you fall in love with it.

 

[Steny]

I have a 2016, tow 20’ flat bed with desert toys four times a year interstate. I drain, not flush, my fluid every 50,000 miles. At 146,700, I’m due for another drain in 3,000 miles. No problems yet.