I changed out most of the fluids within days of getting her home.
I have some pics of the G2 rear axle cover and the 24204278 transmission pan. If I can find them I may edit them into this post.
My oil pressure gauge was rock steady on the centre line with it running when I brought her home.
6 quarts Mobil1 5W30 and a Baldwin B31 oil filter. Now the oil pressure gauge moves with the engine RPMs.
I changed out the oil in the front and rear diff with 88900401 AC Delco 10-4016 75W90 Synthetic GL5 gear oil with NO Limited Slip Additive that's claimed by some to smell like grape juice... It smells like brimstone just like I expected. I paid $11/qt to Summit for 10 qts. I figured the low price might not last... It's gone up to $18/qt and it's back down under $17 now.
The front diff actually calls for 80W90 dinosaur juice but the 75W90 synthetic should be just fine. The front is an open diff but I have a G80 locker in the rear axle so I don't want to use anything with limited slip additive in that and the front axle just doesn't care... Just need to be aware...
The 10.5" 14bolt fill plug was set up tighter than a drum in the casting. I broke off a 3/8" square extension and a socket purpose made to remove square recess drain and fill plugs. That was enough... I just replaced the cover with a G2 Aluminum unit that didn't claim to add fluid capacity. The replacement cover has a thermal sensor bung at the factory fluid level as well as a fill and drain bung so I can drain and re-fill from a more accessible location.
The fun little gotcha with this cover is it's drilled for the 3/8" bolts used on the old GM 10.5" 14bolt axles. The 2005 2500HD has an AAM 10.5" 14bolt with 8mm cover bolts... Essentially the same axle but some nit picky little changes... I made up some spacer sleeves out of 3/8" copper tube that threaded down the bolts and filled the space between the holes in the cover and the 8mm bolts nicely. The actual clearance is tighter than the 3/8" bolts that came with the cover.
No pictures. It's painted black so it doesn't scream "I'm Here!!!"
I'm not sold on how wonderful an aftermarket axle cover with a different internal profile really is... I've been watching Gale Banks axle cover series with interest. I'm probably going to TIG an O2 bung into the factory cover at the correct fluid height and put it back on the axle in the spring.
The NV263HD Transfer Case took just under 2 quarts of the GM reccomended Manual Transmission and Transfer case replacement for Dexron III... 88861800 AC Delco 10-4033. It was $7/qt or thereabouts compared to the Dexron III "compatible" oil from Mobil that was around $15/qt.
The axle and transfer case oils weren't black as pitch and they didn't have pretty shiny flakes of metal either but they weren't nice and clean... I've drained and re-filled the axles and transfer case once more to make sure they were running clean oil.
I changed the strainer and oil in the 4L80E. The oil was your standard not so clean ATF. Not filthy but not super clean either. It probably had been run all of the 84,000 miles the odometer showed.
I used Dexron VI. The Delco fluid was cheaper than the WalMart Supertech this time even with shipping. Dexron VI is Dexron VI. Get whatever is the least expensive.
I replaced the GM stamped steel pan with a GM 24204278 stamped steel drain pan that has an actual drain plug... Yet more decontenting from the 1999-2002 models.
I replaced the flexible magnet in the old pan with an M74 Allison 1000 transmission fluid filter magnet. This is the magnet that GM recommended in a TSB for the 4T65E and 4L60.
The WIX filter came with a flat gasket but the stock GM pan gasket is re-usable... so I did.
Make sure the strainer seal is replaced and be careful to not gouge up the bore where it seats. I've read posts by guys that didn't replace that seal and "Can't figure out why the transmission won't work."...
I also installed a Magnefine filter in the radiator cooler output line. The new filters have spun metal housings rather than the old much counterfeited HDPE plastic housings. I have yet to cut a used one open with my huge pipe cutter. I'll post pictures when I do.
The goal is to be able to change the accessible 25 micron Magnefine filter every other engine oil change... and change the Dexron in the pan out every 2-4 oil changes.
The strainer is 110 microns and the Magnefine is a much finer 25 microns with its' own magnet. So... In theory, changing the inexpensive Magnefine and scheduled easy ATF changes should keep the ATF and strainer and pan magnet clean enough that the pan should never need to be dropped again barring solenoid or some other internal failure.
I'll be replacing the factory KNP AUX transmission fluid cooler with a 40,000 lb Hayden Tru Cool 47391 LPD unit and installing a fresh Magnefine filter in the line between the radiator fluid cooler and the AUX cooler.
There's a fellow on Performance trucks that sells a kit to use the factory AUX transmission cooler lines on the GMT800.
https://www.performancetrucks.net/fo...rdware-508374/
I installed a Hayden Tru Cool transmission cooler on my 2009 Impala SS several years ago using the GM AC Delco 191300039 Jiffy Tite line adapter fittings that screw right into the Hayden threaded fittings.
I had to fab the brackets for the Impala and make up the mating tubing with my MasterCool HydraFlare and Parker Bead tools. I used constant tension band clamps. It looks close to stock and by golly it doesn't slide around and leak like some of the Micky Mouse hose setups I've seen on some rigs.
I haven't done the power steering or flushed out the old black brake fluid... The brakes desperately need a flush with fresh fluid. I bet this stuff is the original 2005 GM DOT3 fluid they poured in it on the line.