That is the only trans I haven't had the pleasure of destroying yet, the NV5600 but might give that a try. I had a CDL for a few years and worked at International as a truck porter, I can even kill Road Rangers...LOL! I am looking at a local International toter with the 444E (7.3 diesel in the Ferds) but haven't found out what trans is in it yet. I am also thinking about retiring...

Several of us ran FL series about 20 years ago. Medium duties are a different world. If you don't like your local dealer service, you'll hate big truck service departments, at least back then. Half assed and half done seemed to be the order or the day. One of us had a Fuller Spicer FS6406 puke at around 40,000 miles. What I DID like, you can hammer on these things all day long without worrying about breaking stuff. They make one ton components look like light weight toys.

Even the highly vaunted NVG 5600 isn't immune from failures.

https://www.cumminsforum.com/threads/nv5600-to-fso6406a-6-speed-fuller.41978/

you know dam well their is some guy with a mid 80`s dodge with the body falling off hauling a ton of junk daily with the trans fluid has not been checked in 8 yrs

If a gasser is a must I'd be going for the ford 445" (7.3L) - some early ones has plug wire issues but its fixed now, modern pushrod bigblock FTW

Rather then buying a new truck, I would be considering a trans specifically built for what you do. If this last factory trans lasted 280K for you, having one built just for you should last at least as long.
When you get the "new specially built for you" trans installed, you can sell that "rebuilt" unit the dealership installed and recoup some of your money.

I am also thinking about retiring...

Rather then buying a new truck, I would be considering a trans specifically built for what you do. If this last factory trans lasted 280K for you, having one built just for you should last at least as long.
When you get the "new specially built for you" trans installed, you can sell that "rebuilt" unit the dealership installed and recoup some of your money.

G, I know exactly where that picture was taken,, less than 10 miles from me.

Track down a cheap, decent, running when pulled, used tranny from somebody that ya at least 1/2 way trust. Give up a couple square feet in the trailer to carry it with you. Kinda like ya probably do with oil, a/f, a belt or two. I'll bet you'll never need it.

[quote=RWG75]

Start doing periodic oil analysis of ATF, engine lube oil and differential gear oil.
This analysis is an added cost, but not too different than paying $ for a “lifetime powertrain warranty.”

Getting +280,000 miles from a new 66RFE is actually a success, isn’t it?
Trans would have lasted longer if the guts of torque converter had not failed?

Logic would suggest: change the torque converter either at 250,000 miles or when periodic oil analysis shows a rapidly increasing concentration of “wear metals” in the ATF.

Always buy new, unused (never reman) torque converters and transmissions.
(meaning quality control is better at factories than at rebuild shops)

Start doing periodic oil analysis of ATF, engine lube oil and differential gear oil.
This analysis is an added cost, but not too different than paying $ for a “lifetime powertrain warranty.”
Both are a special type of insurance.
Throughout the mining, heavy machinery, transportation and military organizations - oil analysis is accepted as more benefit than cost.

My 46RH transmission died at 187,000 miles when the Torque Converter lockup clutch failed and sent debris through the transmission.
This happened after I changed out Mopar ATF+3 with added “Red Bottle” Lubegard
to straight Mopar ATF+4 with no Lubegard.

Maybe other Moparts members could comment on whether:
torque converter failure is the root cause more than 50% of the time in various model MOPAR automatic transmission failures?

In the late 1970s a company I was a supervisor at bought a Mack Midliner truck to make a 240 mile round trip five days a week.
This “made in France” truck went 1,000,000 miles by 1987 without a major breakdown.
The truck had a very good driver with a great work ethic who respected equipment.
Mack came and gave him a jacket with “million mile” emblems.

When someone said to me:
“So Charlie Babb has done such a good job looking after his truck that now you are going to “reward him” by making him keep driving it until it breaks, perhaps causing a road accident where he might get injured or dies? “

So even though money was extremely tight, I bought Charlie a new Mack Midliner.

I hate mopar reman transmissions, I have pulled apart 48REs with V8 planataries in the OD section and all kinds of weird junk, seems they just grab parts out of a big ole bin and if they physically fit they just throw it in there. I would find someone that knows that specific trans very well and have them build me one, it should still be cheaper than injectors on a duramax.

The vast majority of 4 speed rear wheel drive dodge transmissions I have had to re-build were caused by leaking cooler lines, leaking pan gaskets, lack of maintenance (including filters and periodic band adjustment that almost NEVER happens during service anymore). Almost never saw a bad trans that did not have leaking fluid or improperly adjusted bands.