Dreaded questions, fluids and filters

[duckmans83]

Gotcha, I know fram sucks. From experience! I will check the trans fluid at Walmart. My use for the truck will be 98% towing at 12k lb camper so want to do what I can to make it last.

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[duckmans83]

Looks like the factory fuel filter is dual layer filter for 10 to 4 micron.

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[duckmans83]

Man, too much info out there. So for the trans, sounds like just drain and replace spin on filter. Don't mess with internal filter? Book says fluid and filter at 25k miles for heavy use.

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[duramax on fire]

Can't hurt to replace internal could it?? I did mine. I agree on the dex3 but not for the transfer case if its push button. Shift on the floor yes dex3 but push button needs delco trac or water ever they sell at the dealer.

 

[duckmans83]

Sounds like you can't get much fluid out so might just dona quick spin filter and fluids, then after my trip next weekend do both.

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[duckmans83]

Walmart didn't have much. Just picked up some t6 and acdelco filter. They had prestone dexcool stuff but were out of distilled water so will do that later. They only had supertec trans fluid so didn't mess with that.

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[torqued2dmax]

Walmart didn't have much. Just picked up some t6 and acdelco filter. They had prestone dexcool stuff but were out of distilled water so will do that later. They only had supertec trans fluid so didn't mess with that.

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EFI tuner , 125,000 MI , will be towing anytime truck is in use , 05 LLY , It is good to learn about the fluids and filters now because you may be needing to change them again when you need head gaskets & studs and a transmission & converter but happy towing until then and do not jump on it while towing , tuned , in 5 th !

 

[2004LB7]

Fram's tough guard and synthetic filters are actually quite good. Both of these are typically sold Walmart. Their basic filters are the junk ones.

If your not ready yet to switch over to a CAT filter/adapter then the Racor filter PFF50216 is probably the next best one. Has water separator built in and fits the stock housing. These are what I run

For the rear diff just run any 75w-90. No need for anything fancy or with special additives. Just make sure it is a good quality brand and you will be fine.

Transynd is good stuff but can be costly. If it is too much for you get some good Dex 3 fluid. Only change the external filter with a genuine Allison filter. Unless you are doing major work or a rebuild you shouldn't have to touch the internal filter

Enough oil. I run T6 but most any 5w-40 or 15w-40 diesel rated will do just fine synthetic or not

Transfer case. Normally it is two quarts of ATF but many have found it real low or dry when checking it. To help with this some, including myself, run 3 quarts of 5w-30 oil. Lasts much longer and provides better lubrication. There are several threads on this if you want to read up on it

 

[duckmans83]

EFI tuner , 125,000 MI , will be towing anytime truck is in use , 05 LLY , It is good to learn about the fluids and filters now because you may be needing to change them again when you need head gaskets & studs and a transmission & converter but happy towing until then and do not jump on it while towing , tuned , in 5 th !

The pcm was programed for heavy towing I guess and doesn't have a programmer. Good to hear all the good stuff about the duramax, haha, y'all are scaring me. Is it that bad? My 7.3 did great just not a big enough truck for a 35 ft 12k lb camper.

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[duckmans83]

My 7.3 feels faster if that means anything as far as the duramax tune that I have. But the 7.3 is lighter and has a bunch of stuff done to it besides turbo and injectors.

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[duckmans83]

Thanks for the info, i will look up the transfer case oil stuff.

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[duckmans83]

So, with all the worry about the head gaskets and trans, are there things to beef them up? Trans cooler, tune tcm, install shift kit?

So after a built trans and head gaskets and studs, is this thing solid for towing?

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[2004LB7]

There are loads of threads on beefing these engines up. This is a performance site after all

Having a larger transmission cooler myself, I would vote on an oil cooler before a trans cooler. I may even convert mine over some day

There isn't really anything in the tuning other then raising shift points that will do anything to help it hold more. You could install a transgo jr. Which may help it last a bit longer. But nothing beats a built trans

Also, as far as your last question, no warranties or guarantees implied. :hug:

 

[duckmans83]

I have torque pro so will be setting that up to monitor things while towing. I'm sure there are post about that so will have to look up the stuff to monitor.

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[duckmans83]

So and oil cooler first, these things don't have one or just too small?

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[2004LB7]

Tool small for anything beyond stock and towing heavy. Most can get away with it but with the 05s propensity to overheat I would do an oil cooler to help. The transmission can tolerate quite a bit of heat but if you loose oil film strength then game over

Also, if yours does run hot, even after cleaning the radiator stack. You may want to look into a lower temp fan clutch such as the Hayden. And lower temp thermostats too

 

[duckmans83]

So add oil cooler to the list. It seams to be at a good temp when driving empty as long at the factory gauge is right. So it sounds like the intake elbow to the turbo is a must to keep things cool.

On my 7.3 I used restore and restore plus to flush the cooling system and got a bunch of crap out. Anyone recommend a flush or just water?

Pic is of the exhaust, egr delete, intake, and tune from September 2018.

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[torqued2dmax]

The pcm was programed for heavy towing I guess and doesn't have a programmer. Good to hear all the good stuff about the duramax, haha, y'all are scaring me. Is it that bad? My 7.3 did great just not a big enough truck for a 35 ft 12k lb camper.

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These are good trucks , to turn it into a great truck that you want to keep , it takes time on this site and some money ! The turbo mouth piece is important , many like Mike L s transmission cooler and as stated clean out the cooling stack after removal . You might want to do a pump rub kit prior to your t case self destructing !

 

[duckmans83]

Cool, pump rub kit on the list.

Did the same thing with the ford making it better. This is just a different truck I have to learn.

Thanks for all the help guys!

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[2004LB7]

Dexcool doesn't normally build up any sludge unless mixed with green coolant or if it is run low to often allowing air to mix into it. Not sure what the 7.3 used but I'm guessing the standard green stuff.

If you want, not everyone agrees with this method, you can flush it out with cascade dishwasher powdered detergent. Drive around for a day and dump it. Fill with water and do the same. Rinse out a bunch of times until it is clean and clear then fill with your coolant of choice