going to drop the oil in the auto transmission this week, and also change filter.i know any metal bits are bad news, anything else to check while i am there? it has been serviced but never rebuilt just a band adjustment in 2011 to my knowledge.. it has over the years hauled some big loads and had some big hills to pull. do they last like indefinately if not overheated etc or? i was told by a shop years ago on my other truck, 250-300 kms is possibly rebuild time? thanks for any info.

 

there's not a whole lot you can see when you just take the pan off. A simple visual inspection will tell you a lot. As far as when you should get it rebuilt, it's always different. If you're not overheating it, you're not having any trouble, and you're not about to drive from California to Maine, I wouldn't even bother to be honest. But if you're fluid is burnt up, or there's darkening on the internals than Maybe you could do it as a prevent it. But that still doesn't mean you need it.

just make sure that when you check your refilled level that you give it time to fill the converter before you do. Seems like a lot of people miss that. When it's cool the fluid drains back out internally by design. So it will show a really high level even though you're not that high.

while you're messing with it make sure you check the dipstick tube that goes into the Bell housing. It's just a rubber o-ring and they get worn out. You don't want to have something stupid like that screw you up. Check all the wiring!

if you can see the overdrive solenoid make sure the wires look good on it and that the connections are still tight.

 

The converter is the biggest tranny killer on the diesel motor automatics, they have to be "loose" by design and as they get older they start to slip and overheat the fluid.