I'm (slowly) doing the 30,000 mile service on my truck and noticed while changing the rear differential fluid that it started to leak out after lossening only the bottom few cover bolts. I went ahead and removed all the bolts anyway, drained the remainder of the fluid and reinstalled the cover, added new fluid, wiped the magnet, etc.

Seems like the other trucks I've owned (mostly chebbys) wouldn't leak until the entire cover was pried-off because they used a liquid gasket sealer instead of a reusable one like the Dodge.

Anyway, when I did the front diff it looked like it was going to be a pain to get my torque wrench on the upper three most cover bolts to tighten them, as there is a suspension piece in the way. So, I just lossened the bottoms ones and let the flluid drain out instead of removing the entire cover.

Other than the obvious disadvantages of not being able to inspect the internals, and maybe not getting 100% of the old fluid out, is this an acceptable practice? Whaddy'a think?

 

I think ideally, it would have been better to remove it completely and inspect the gears. I like to spray the area out with Brake parts cleaner.

But, having said that.........I don't think your axle is going to fall off of your truck either. I am sure draining and refilling is better than nothing. I know lots of guys who have gone a WHOLE lot longer than 30,000 miles without touching their diffs. Good luck.

 

BTW, just a data point. The rear diff fluid was starting to look pretty black. The front was a little better, still had some color to it. I do tow some (max 8,000 lbs).

 

Yeah its fine just to drain and fill.
Most people on here that complain about not removing the cover haven't even changed the diff oil in their own truck let alone removed the cover.

 

Everyone talks about changing there diff fluid at 30k or less, Why is that? What has changed in the fluids over the years? I remember when a person used to never change the diff fluid and it would last for thousands of miles, now we a supposed to have this great synthetic fluid and we still change it at 30k. Same way with the transmission fluid, a person might drop the pan once in a cars life and change the fluid now we are changing in at 15k intervals. Not arguing a friend and I were talking about this the other day.

 

Yeah, good point. Just trying to keep my warranty intact.

Especially the tranny, I better pay attention to my 47RE to keep the warranty valid.

 

The most important dif oil change is the first one. I do the first change at 10k miles. That gets the phosphates and metal particles that result from break-in early reducing wear. First change is always metal flake oil and dirty. Next change will be much cleaner unless you have a problem.

DT<*)))><

 

To get at the pesky top bolts on the front cover, I jacked my truck up on the frame, on the driver's side. This allowed the suspension components to clear the diff cover. I decided to remove the cover completely because there was a little bit of grit on top that got dislodged when I loosened the bolts. I didn't want this to get into the diff or on the seal.

 

Got to keep DC shop busy!

 

Yep. I second that. The first one is probably the most important. I drained and removed the cover at 15,000 miles and it was very dirty looking. The second change at 30,000 was much cleaner.

 

Don't use your torque wrench to tighten the bolts back up. There have been numerous threads here about breaking the bolts when trying to "torque" them to specs. Just snug them they say now. That's what I did and no leaks.