The controversial question of when to change the fluid in the 5R55E automatic trans

[Lube]

Lots of opinion in this thread, some justified and some is just mythology. If you want to KNOW what the condition of any fluid lubricant is, GET IT ANALYZED! That eliminates all the guess work, saves money and saves time. Doing anything else, regardless of the fluid brand, type, color, viscosity or any other adjective applicable and you're only guessing. You may be right, and you may not. As transmissions are expensive, I prefer knowing. An oil analysis is 100% definitive about the condition of the oil, and if you do them regularly they will also give a very good indication of the overall condition of any component that you're doing analysis on.

As to Amsoil being best - believe what you like. After their 100% cloning (test results available) of Allison Transynd fluid, which is no better than mediocre and which is what you'd expect from a Castrol product, they don't get any votes from me.

 

[ophidia]

http://www.blackstone-labs.com/services.php

They send you a "free" collection kit.

 

[Lube]

http://www.blackstone-labs.com/services.php

They send you a "free" collection kit.

Blackstone is good, but I find the reports from Polaris easier to read.

 

[joe doe]

When a customer comes in with a transmission that has severly darkened transmission fluid or previous transmission problems, we will absolutely not perform a fluid change due to the fact that most likely it will come back with a failed transmission shortly after the change. This is fact and has been proven definitively.

Mike's Auto Repair
ASE Certified Parts Specialist
Service Manager

i would tend to agree with this statement .on a whim i had my trans fluid changed .it was not darkened but did have well over 130k on it and never had a change before .
so i had my mechanic change it .shortly thereafter(couple months)the trans failed(lost reverse)coincidence??i think not .

i should have followed my own rule ,if it has 100k on it and you never changed the fluid and it runs great still,dont mess with it .

 

[ecw24]

In regards to transmission failures after flushes, check out the link not sure if it has been pre-posted http://www.amsoil.com/lit/filter_man_council01.pdf

Just my 2 cents.

 

[Mkiester]

I have 273k miles on my 2005 2 wheel drive and out of guilt changed the fluid some time in the past.

I just changed out the engine because of a blown head gasket.... Long story.

Mike