I did mine at 15k, 30k, and last week again at 50k. The first time the factory fluid looked horrible. But the last two times, the Mobil 1 75w90 looked as fresh and new as when I put it in. I will prob go to AT LEAST 75k the time around which would be 25k on the oil. As good as it looked I bet it could go to 100k now, but I know I won't wait that long .

 

I did mine at 15,000 on an o4 and the the CRUD that came out was terrible!
I now have an 06 and just did my first at 5,000 (put on a pml) and the factoy stuff still looked bad. Makes me wonder if the stuff from the factory is some "Special Goo".

 

I'm with you on this one.... thought most diff's that use 80-90 wt oil have a tendency to last a long time. with or without oil change.

I've never changed out diff fluid on any vehicle I've owned. if there's a failure mode here? of course I'd be glad to change...

 

It's just good PM that gets overlooked by a lot of people.....
If it helps with the life of the drivetrain at all, i'll keep doin it

 

If I recall the 15K change is for the server usage and 30K for normal use. I only have 10,500 on mine and will do it's first diff change this weekend with Amsoil and not worry for the next 30K as i do not tow/haul heavy.

Just my $0.02

 

no question it will not hurt to change out regularly.

but is it really needed? 80-90 hyploid oil just don't break down easily.

are there documented diff failures from oil not being changed?

new to CTD, but certainly not new to vehicle maintenace. seldom do you ever hear of a diff failure due to lack of oil change or any other reason.

 

only diff failures I have heard of are the ones that came from the factory under filled.

 

if there's almost no diff failures reported...

I'm checking mine for leaks and correct level. then if everything looks OK. I'm leaving mine alone...

more worried about taking apart rear wheel to check brake shoes and repack wheel brgs.

frt wheel brgs from reports are sealed, so no way to do maintenace.

going from stem to stern, diff fluid is last on my list...

 

I thought that it was every 15,000 for severe service or never for light duty. That never made real sense to me.
Joe

 

I never tow, never do anything, just drive.... i have 33k im not changin mine..

 

so you're gonna repack the rear wheel bearings?

 

started with 96k miles... are going thru CTD stem to stern.

changing all fluids necessary, then repacking all bearing possible, shooting grease into all zerts and injecting grease with a needle into places without a zert.

I've got a thread started finding out mileage of failures for common items. will then service and/or replace accordingly.

 

It's your truck...Do what you want. But, im telling ya....That factory fill was some NASTY looking stuff when I changed mine the first time at 15k.

I think you should at least consider changing it once now....and THEN NOT CHANGING IT.

 

TexasCTD is right - lose whatever is in there from Dodge, and refill with the proper amount of Royal Purple or RedLine... then never change it if you must!

 

where is the best place to buy the gear lube? Napa? Autozone? wally world???

Thanks