I've put 35,000 miles on my Durango and never touched the Trans or Transfer case. I'd like to change the fluids seeing as I've done every other fluid except these two. I know I want to use ATF4 in both but I have a couple questions. I know just dropping the pan won't get all the trans fluid out and I'm not sure whats in there now, but I know its not good to mix synthetic with non-synthetic fluids. I wonder if I should even worry about the trans seeing as the fluid is still red and doesn't smell burnt. Don't fix it if it ain't broken? I've heard you should do the transfer case and trans at the same time, is this because they share fluid or because they're right next to eachother? I think this is my stupid question>The transfer case and transmission don't share the same fluid right? If I decide not to mess with the trans I'll just drain the transfer case and refill with ATF4. Thanks in advance guys.

 

1. You should change the fluid every 15K in my opinion. 35K is ok so don't worry.

2. There is no problem mixing regular with fully synthetic. There are made out of the same base and additives. The issue is that fully synthetic base is broken down to 2 microns. So using fully/regular mix you don't get any extra protection because the regular fluid base has more impurities therefore breaks down faster and causes ware. The best thing to use is Fully Synthetic. Blends should be treated like regular fluid.

3. Don't worry about getting all the fluid out. Dumping the filter and pan will dump about just over half. If your goal is to go Full Synthetic then you need to dump the fluid 3 times to do a change over fully. You can add one of these to make fluid changes more easy and draining the pan easyer but you need to still change the filter. Don't forget to adjust it if required.


4. The trans and transfer case do not share fluid. They have their own fluid there are just married. They do need the same fluid tho. You do them together because of the maintenance scheduals. AKA 15,000 mile interval.

5. Good luck.....

 

Don't think I could of said it better... Only thing I would add is stick with a name brand fluid..

 

Ive owned my Durango now for a while. Its my 1st 4x4 vehicle. I have only had it in 4wd twice. Should I still change the fluid?

 

Sean,

I would... Not only does wear break down the fluids, but as does time...

 

The manual say every 37,500 miles or every 30 months depending on what comes first..
This is regardless if you have had it in 4 wheel drive or not. I myself would say 25,000 miles would be the max I would go without changing.

 

Change the fluid if you use it or not.

Even though you don't use the 4X4 function the transfer case is still in use. The front end is still spining and the rear diff's are too. Therefore the transfer case gearing needs to be lubricated and therefore the lubricate is still breaking down.

I prefer to change out fluid every year or 15k respectfully. Going 37,500 mile intervals is ok but I like extra protection.......LOL

Fully Synthetic change over (which is ATF+4) will last longer because of less impurities. So you probably can do 30K intervals with it and be overkill.

I think I would do Dealership ATF+4 because of the relationship of the manufacture and their contractual alowance.

 

Fully Synthetic facts!


As per the law, a company can name a Fully Synthetic if there are one of two factual alowances.

1. The oil base is broken to 2 mirons or lower..... I know Mobil One does this step.

2. If the oil base is processed long enough......... AKA.. The cheap brands.


IDK....what other brands do but I know that Mobil One does fully break it down and that hintz the cost differance. Going through a dealership you will get the real deal if you do your homework on assossiated accounts to ensure quality.

Fact number 2.

OEM filters are one of the best filters because of ridged contracts.