I have a 2004 Dodge Ram 3500 with just over 36,000 miles on it. The scheduled service book that it came with has two sides, one that is more towards heavily worked trucks (aggressive about fluid changes and service on high wear parts) and one that is more geared towards light duty. Because I didn't meet any of the criteria for 'heavily worked' I've been following the light duty schedule. After reading a few posts on here I noticed that people were changing their front and rear diff fluids at around 30,000 miles. I looked in the scheduled service book and the light duty schedule doesn't have you do that until 100,000 miles. It seems like I should do it earlier than that so I'm considering doing it this weekend. I called the dealership and they want just over $200 to do it.

Questions:

1. How hard a job is it relative to an oil change?
2. Where can I find the information regarding the fluids - how much, dino vs. synthetic, and what weight?
3. Is there a post or an article somehwere that describes the procedure step by step? I'm a bit new to wrenching...

Thanks guys,

Aaron

 

Go to this site's Main page, and over on the right side there's a Search Forums box. Click on 'Advanced Search' and when you get to that page, type in Diff Fluid Change. Then go down and make sure it searches in the 3rd Gen - Engine and Drivetrain section. Then initiate the search. There's hours and hours of reading on this subject.

But, in a nutshell:
1 - No - it's not much harder to do than an oil change, but getting to some of the bolts on the front axle can be a challenge.
2 - My change takes about (if my memory serves me correctly) 9 qts of 75W90 Mobil1 Synthetic Gear Oil. I got a bunch of it on sale at Advanced Auto Parts a while back for about $7 a quart.
3 - I'd highly recommend a torque wrench to ensure even tightening of the bolts, and be careful - some guys have had the bolts shear off with no additional pressure. I'm really thinking about getting a couple of extras just in case I need them before the next change.

 

It isn’t that difficult, just be really clean about it. Be sure to clean all around the differential housing fist, especially around the top. The reusable gasket isn’t quite as large as the cover or housing so grime can collect on the top of the gasket and will fall on your ring gear when you open the cover. I’d go around the outside with a plastic bristle brush or something.

The front is a bit tricky because of the track bar, however with a little patience you can get the bolts out.

Grab yourself a rag and try to clean out the bottom of the inside of the housings the best you can too after the oils drains. I can’t remember if these things have magnets in the bottom or not?

You’ll feel good about your truck knowing the job was done right. You’ll be surprised how big those gears are too. Have a beer for me when you are done.

I wonder how the dealerships do it? I bet they just suck the oil out through the fill hole or something. Which probably works well other than you can’t clean the grime out of the bottom or inspect the gears.

For $200 the dealership should take you out to dinner too.

 

I just changed mine (rear only, I have a 2WD). I installed a PML aluminum cover, so that next time, all I have to do is remove the magnetic drain plug.

I used 6 quarts of Royal Purple synthetic 75W90.