Changing Diff Fluid for the !st time.

[WilliamU]

When changing the diff fluid in my 2500 4x4 can I use any quality synthetic fluid? The owners manual says that the American axles don't need the limited slip additive. The way it reads though, I wasn't sure if they used a special synthetic for LSD or just synthetic without LSD additive.



Also is there anything tricky about changing the fluid in these axles. I've changed plenty of diff fluid but thought I might ask in case they did something wierd with these. I already know that you have to use a gasket instead of silicone, but not sure if anything else special is reqiured.



How full do you fill these axles? Everything I've changed in the past I just filled level with the fill hole. Can I do these the same way?



Thanks in advance for any info you guys can share. I've worked on my vehicles for many years, but this is my first brand new vehicle and first diesel, so just trying to cover all my bases before I get into something new.

 

[Bertram65]

Lots of info on this if you do a search, when I changed mine I put in Amsoil 2000 75/90 filled the diffs to the bottom of the fill holes, took 4 quarts in the back (11. 5" rear diff) and 3 in the front. The gaskets are reusable and do not require any sealant when you put them back back on.

 

[SRadke]

If you've done it in the past you'll really appreciate these reusable gaskets. No pounding, prying, cussing, or scraping. My best advice is do not over torque the bolts. There have been a couple reports of bolts twisting off and that will ruin your day.



-Scott

 

[t6_man]

Originally posted by SRadke

If you've done it in the past you'll really appreciate these reusable gaskets. No pounding, prying, cussing, or scraping. My best advice is do not over torque the bolts. There have been a couple reports of bolts twisting off and that will ruin your day.



-Scott

Been there; done that. I have a 2wd, so I can only address the rear differential. Quite easy, takes just less than 4 quarts (I used Mobile 1 synthetic), and the reusable gasket is great. For my '03 with an 11. 5, the manual states to fill 1/4" below the fill hole, +/- 1/4". Just don't twist a bolt off, like I did. I was trying to be perfect, but guess my torque wrench was faulty, and twisted a bolt right off. Scott is right, it DOES ruin your day!

 

[WilliamU]

I bought new gaskets. I didn't know they were reuseable. I guess I'll be returning those. What should the bolts be torqued to and is it the same for the front?



Thanks for the help guys. The reuseable gasket info just saved about $50.

 

[SRadke]

I believe it is 30 ft/lbs. for the rear, not sure on the front. If the bolts are the same I would do it the same. Some interesting reading here:







https://www.turbodieselregister.com/forums/showthread.php?threadid=87488&highlight=rear+diff+bolt+torque



-Scott

 

[Eric_77]

I just did mine and changed to Mag-Hytec cover and AMsoil. Inarush did it for me and as I remember it used 8 qts so that is pretty hefty increase in volume for those that tow or are worried about rear end.

 

[Spooled-up]

To get all of the fluid out of the axles, jack up one side of the axle at a time and more fluid will come out of the tubes. I got some more drainage when I did this. Also, there is a depression on the bottom of the housing under the ring gear. I scooped out as much fluid out of the depression with my finger as I could. Didn't want any of the old fluid left in there. I guess I'm pretty picky about stuff like that.

 

[WilliamU]

Thanks Guys for all the help. I am going to change my fluid this weekend.



BTW Eric_77, how much was that cover?