Those of you that have the 5.4 w/4R70W trannies, are you getting a lot of miles out of them? I did some research and they seem to be durable.
I bought my 02' 5.4 w/4R70W and been driving it no problems, took it to the mechanic for routine fluid change , he told me he didn't think the transmission fluid had never been changed ( found the factory plug in the pan) not funny though truck has 142k could this be possible. Any opinion would be good...thanks

 

Well I hav that trans but it has a 4.2 turning it. I have 122,000 an never changed it and it's running strong and first day I got it.

 

I think I'm the second owner , I got it with 135k , I looked at tranny fluid and was still red when I bought it, I'm wondering if the last person that changed it just left the plug in the pan..?

 

They say that if you don't change it for more than 100k then your not supposed to. Idk how true that is but I've heard it multiple times

 

Op, the trans fluid was probably flushed, instead of dropping the pan. The 100k thing is for flushing only as that can stir up particles and get clogged in the trans. dropping the pan is ok and messy

 

hmm

 

Like I said I'm not to sure how true it is but I've heard it multiple times. Like stated above I was corrected to transmission flush

 

I got a 4.6 with the 4r70 it has 251k never rebuilt never abused and never pulled a trailer and it's about shot it's been wore out since 160k I'd say it's a pretty reliable tranny

 

This is true. When you leave the tranny fluid untouched, it breaks down over time and collects transmission debris from the tranny clutches, etc. The oil becomes thicker and contaminated. Because of this debris, the old fluid actually holds the transmission parts together and keeps everything working. When you put new tranny fluid in, the transmission will start slipping because the fluid is too thin. Hence, most shops will tell you NOT to change the fluid IF it has NEVER been changed before and the mileage is high. If you have around 50k miles and have never changed the fluid, you would probably be OK to change the fluid. Most people say to change it every 30k. Also, many people avoid tranning flushing because it flushes out the debris holding everything together. While a fluid change just takes the fluid out without pressurizing the tranny parts.

 

I guess time will tell ,it seems to be fine now I only have a couple hundred on after the fluid change.
BTW they didn't flush it just a change and filter....like I said time will tell , and thanks again for your input I really appreciate it.