Trans service way overdue

[nrschaaf]

Hello all, I'm curious about doing a trans service on my '97 X 5.0, 4R70W, AWD and had a question. The previous owner did not do any services and she's got just over 120K now. I've heard that if you but fresh oil in an old trans it'll ruin it from some people and the opposite from others so I'm not sure what to do. My only experience doing this was an old Lincoln with an AOD that was on its way already and it only lasted a week after being flushed so it's not a good reference. My trans isn't acting up at all, but the fluid is alittle dark.

 

[5.0L V8]

Do a FULL flush, including the lines and torque converter. I thin it's like 12 quarts or something. Replace with Mercron V and throw a bottle of Lucas Transmission Conditioner in with it. I JUST did all this on my 97 5.0 AWD with 125k. I can tell a substantial difference in smoothness. Do the transfercase while your at it.

 

[5.0L V8]

And of course replace the Filter. Preferably Motorcraft.

 

[koda2000]

i'm kinda in the same boat. '01 5.0 with 4R70W trans. truck was recently purchased with 180k and i don't know if the trans has ever been serviced.

common wisdom is that if the trans fluid is not pink and smells burnt, leave it alone. the reasoning being that the clutches are already fried and the trans is using the clutch material suspended in the dirty fluid to keep from slipping. if you put fresh fluid in, the trans will slip distroying whatever remains of the clutches.

my fluid is very pink, clean and smells fresh, so i don't know what to do. i belive the fluid has been changed at some point, but i have no idea when. i'm leaning toward changing mine. i hope i won't regret doing so.

 

[tchalm]

The other side of the discussion is that if the trans fails after being serviced, it would have failed anyway. So, it's better to service the trans and hopefully get it to last longer. And it would be even better to have a pro do the job and do whatever adjustments make sense or replace whatever parts are clearly failing.

As a very wise guy said, A stitch in time, saves nine. (Sometimes.)

TChalm

 

[koda2000]

The other side of the discussion is that if the trans fails after being serviced, it would have failed anyway. So, it's better to service the trans and hopefully get it to last longer. And it would be even better to have a pro do the job and do whatever adjustments make sense or replace whatever parts are clearly failing.

As a very wise guy said, A stitch in time, saves nine. (Sometimes.)

TChalm

that's fine if you know you're vehicle's service history and as far as having a "pro" do the service... why so i can waste money? for that matter i don't trust others to work on my stuff. at least for you the service cost is apparently tax deductible. there really are no "adjustments" to be made on modern electronically controlled transmissions. you either have a problem or you don't. parts will wear, they will wear faster of you ignore service intervals and/or are hard on your equipment. if your clutches are worn out and you change the fluid it will fail much faster.