First, thanks to this site and the people that have answered my questions. Me and my Duramax buddy knocked out the 30K maintenance in about 3 hours. It's good to know that we did the job and hopefully done it right. He does his and other's, so I'm confident it's done right. I do have a few questions.

On the axles, we used 6 quarts of 75w90 Amsoil Severegear. We filled both until a bent index finger could touch the fluid. Does 6 quarts sound about right or a little low? I've read on here anywhere up to 8 quarts but maybe not all axles are the same capacity?

His comment on the axle fluid was "These are the cleanest differentials I have ever seen". The fluid was pretty clear and barely a metal shaving could be seen.

On the oil I added 3 gallons and it's a hair over full. I'll recheck it in the morning when it's good and settled. It if stays a hair over full, should I drain a bit using my Fumoto?

His comment on the oil was "This is the blackest oil I've even seen". Isn't this standard for a Cummins? The oil is going to Blackstone so I'll know if it's fine.

Last question - any pictures on where to lube the front drive shaft fitting?

 

As long as it's at least 3/4" below the fill plug on both, your good. Lemme see if I can find a link to the pic.

 

Here is a picture of the grease fitting.

This is the needle that I use.

 

you are fine on the diff's. every truck i have ever had, i fill the diff's until fluid starts coming out the hole-then i am done. hundreds of thousands of miles under my belt doing it this way- no problems.

 

On later 3rd gens, on the 11.5 rear dif, there is "Fluid Level" and a line stamped about 3/4" below the bottom of the fill plug. It would be easy to miss if you didn't know to look for it.

As far as the engine being a shade over the full mark, I wouldn't worry about it.

In regard to black oil, the 03-04.5 SO and the 600 seem to blacken the oil very quickly... maybe something to do with the timing of the 3rd injection event for the cat, but in any case black appearance to the oil of your 06 would be normal. Sending a sample to Blackstone is still worthwhile.

 

Being I pulled the cover and let the oil drain for several hours I refilled them until the oil started to run back out and that was over 15K ago and no problems for either axle so far.

 

This is how i have done all of my trucks and twice on my CTD. I have had no problems and i tow about 10k lbs every so often.