thebigrisky1

So I just bought a semi well cared for 24 valve 2002 dodge Cummins off my neighbor. The truck is about to roll 200k miles. He actually got deported and sold me the truck for an 80% discount. I never owned a truck let alone a giant diesel. I love it so far. I cant seem to find a regular maintenance schedule for this thing. I don't want to walk into a repair shop like moron and ask them about the condition and get taken to the cleaners.

Anyone have any thoughts or preset repair lists on what I need to be checking on and repairing and what that regular repair schedule might look like. Thanks

jrs_dodge_diesel

Welcome to DTR! And congrats on the new truck.

All of the maintenance schedules are in the owners manual. If you are not sure on when the fluids were last changed, it would not hurt to do them now.

Here's a short list of what I do:

Engine oil - every 10,000 miles. I put in 3 gallons (book says 11 quarts with filter), but the pan has plenty of room for the extra quart. I buy it by the gallon jug. Valvoline Premium Blue 15w40 works great, and is also endorsed/reccomended by Cummins. Also good to use a Cummins Stratapore filter.

Fuel filter - Every 10,000 miles, usually do this with the oil change. Again, I use a Cummins Stratapore filter.

Transmission - Fluid every 30,000 miles. If automatic, tighten and adjust shifting bands.

Rear axle (and front axle if 4x4) - Every 30,000 miles. Synthetic oil reccomended if you plan on towing.

Air filter - if stock, change it when the little filter minder says to.

Coolant - every 5 years or so. The stuff that Cummins sell (ES Compleat) is really good stuff. And it's blue!

Brake fluid - every 3-5 years. Brake fluid absorbs moisture over time, which promotes corrosion. I have recently had a brake line let go because of corrosion.

Steering fluid - good to change out every 3-5 years.

Tires - rotate every oil change

Wash - as needed


Hope this helps

SIXSLUG

You go 10K on oil, Jrs.? That seems long.....

I go 5K on mine and a Baldwin filter.

I go 10K on fuel filters, again, Baldwin. Read up on changing it. You can get air in the housing and it won't start. It's simple to get it going. Read up before tackling that one...

Welcome to the site!

jrs_dodge_diesel

I do oil analysis when I change my oil (I use Blackstone Labs). In one of the the reports, they mentioned that I could likely extend the oil change interval without any problems, but I choose not too. 10,000 miles works very well for me, and it's easy to remember.

SIXSLUG

I need to do that. I just go oldschool and change it every 5K whether I towed or not.

10K would be nice!

An old mechanic at the plant I used to work at said gear oil in the diffs can go a long time if it doesn't get polluted, no combustion meant it didn't need much attention. What do you think about that?

jrs_dodge_diesel

You too can do 10K oil changes even without sampling. I'm not even using synthetic, and I tow occasionally. Our engines can hold 3 gallons of oil, and modern oils have plenty of additives in them which allows the oil to do well over a longer period of time, so 10K miles is not out of reach for anybody.

The reason I do the oil analysis is to keep an eye on the overall health of the engine, and make sure that fuel and/or coolant isn't getting into the oil (this confirms the integrity of the gaskets and rings). It also gives you peace of mind after an unusual event, like when I recently discovered a torn air filter (Scotty Air II). The sample I sent in after that was able to show that no abnormal amount of dirt came in, and no unusual wear on the engine.


For the rear axle gear oil, I'd still stick with 30K fluid changes there. That mechanic is correct that there is no combustion, but that oil is under very heavy load. Keep in mind that lubricating oil has 4 properties; lubricating, cooling, sealing, and cleaning. Lubricating and cooling are of particular importance in the axle. At any time while driving there are only 3 teeth engaged. One tooth is in full contact between the ring and pinion, another tooth is starting to mesh, and the third tooth is being unmeshed as the gears rotate. All of the engines' power is on those three teeth. This is why gear oil is so thick, so it doesn't get squeezed out from between the teeth (called shearing). The higher the load (like when you are towing) increases the pressure on the teeth. That pressure between the teeth raise the temperature of the gear oil. The axle tubes and differential housing do a decent job of keeping the oil temperature down as air flows past while driving. There are aftermarket differential covers with heat sink like fins, which aid in cooling, but are unnecessary unless you tow heavy all the time.

It would do well to change the gear oil, it lets you make sure that there is no contamination, like water intrusion from a failed axle seal or cover gasket failure. Plus fresh gear oil is far less prone to shearing, so you don't get metal on metal contact.

Hope this helps

SIXSLUG

That makes a lot of sense, I pull the plug and dip it every 6 months. It's still purple and clear and smells right. But it's due!

Since I went back to my old job, my truck is a daily driver, 5 miles one way, and only tows 14K lbs 450 miles a year and that's about it.

I have always intended to do an oil analysis, just never had to worry over it.

jrs_dodge_diesel

Doesn't it smell wonderful when you open that plug?

That's mostly the sulfur compounds that make up the extreme pressure additive in the gear oil that make it stink. The book calls for 75w90 for a normal fill, but suggests 75w140 for towing. Since I tow occasionally, I filled up with 75w140. The oil viscosity will only get as thick as it needs to based on it's temperature, higher temperatures make it thicker.

Don't forget if you have a limited slip rear end, to get a bottle of friction modifier. Without it the clutches in the rear end will be grabby on tight turns, more so when you have a trailer hooked up.

One other thing, the fill level on our axles is not to the bottom of the fill hole. It's ¾" below the fill hole.


I plan on keeping my truck as long as possible, so I had started doing oil analysis so I would not get a surprise event later. Not a guarantee that nothing bad with happen suddenly with your engine, but you will usually see a problem before it happens. Blackstone Labs does a great job, and they will send you free sample bottles on request. They only charge $28 to run a sample.

nothingbutdarts

What if you fill the diff. to the bottom of the threads?

SIXSLUG

^^It'll run out the doorlocks...

Not really, the FSM and Dana Site says 3/4" below on an 80 and 1/2" below on the 60 up front.

May not be too big a deal, but maybe to keep it from leaking at the fill hole, when they are turning they drag fluid up and over the ring gear, reducing the level a bit... when stopped and sitting it may be too much and seep the fill hole....

samiam4

I think you'd be wise to flush brake fluid every other year. Dot4.
Dot3, ever year.
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