Formula for changing axle fluid

[ACF]

Ok, the manual says either never at all, or every 15K if you tow, etc, etc. I do tow but only 5500lbs about 2000 miles a year. The rest of the time the truck is used in the lightest of duty. Given the way I use the truck I am just going to wait till the 30K mark and change the rear end with the trans (48re), would you concur? Change sooner or later?

 

[gathomas]

According to the informatin that I have obtained the greatest amount of wear in these ring and pinnion gears occurs within the First 5000 miles of use... irregardless of what type of use that it is. Play it safe, change at 6000 miles we've got a lot of Financial resource tied up in these trucks.

 

[GaryCarter]

Every 30k I do it all. Front, trans, xfer case, rear. Plus I'm going to start doing the PS fluid and brake fluid as well next time around. Towing about 50% of the time.



Gary

 

[JLibert]

Ok, the manual says either never at all, or every 15K if you tow, etc, etc. I do tow but only 5500lbs about 2000 miles a year. The rest of the time the truck is used in the lightest of duty. Given the way I use the truck I am just going to wait till the 30K mark and change the rear end with the trans (48re), would you concur? Change sooner or later?

Well, there isnt' much info in your sig, so I'd agree with the last post and say 30k should be fine. I changed mine at 25,50,75,100k. The only oil that looked like it should have been changed was the transmission and the diff. The front diff and the xfer case looked new. I did a brake system flush at 100k for the heck of it. I'll probably do the coolant flush at 150k. I don't do a whole lot of towing, but do operate in temps between 15* and 115* .

 

[Bodie]

Ok, the manual says either never at all, or every 15K if you tow, etc, etc. I do tow but only 5500lbs about 2000 miles a year. The rest of the time the truck is used in the lightest of duty. Given the way I use the truck I am just going to wait till the 30K mark and change the rear end with the trans (48re), would you concur? Change sooner or later?

That is not a very good idea, the first change is very important. That is when you will have ALL break-in. I changed mine at 15k, it was pretty bad, and it had never been hooked to a trailor.



Think of it like this, if for some reason the diff starts to whine at 29k and you take it back to the dealer, they will void the warrenty becuase you havnt changed the fluid :{ ..... just do it when you are supposed to, and have no worries

 

[steved]

Like these guys, I found the worst looking stuff was the OE fill... I didn't tow and waited till 50k for the first change... then I did it all...



The fill of Mobile 1 75w90 that replaced the OE fluid didn't "wear" very well and the fluid was looking almost burnt (if you can burn a synthetic oil)... the current fill of Royal Purple is doing better than the M1 in the 11. 5AAM rear IMO... since I have the DT kit, I doubt I will change the front fluid (still M1) much before 200k since it isn't used much.



The transmission... I did the one in my 99 every other... every 10k (or every other oil change) I would dump the fluid in the pan (had installed a drain plug), and every 20k it got fluid and filter changed... that schedule seemed to work well... I have a manual in this truck.



I also change the tcase about every 25k... currently using Royal Purple Synchromesh in this truck (used a full synthetic ATF in the last couple)... the RP stays crystal clear, but I change it more to remove any particles than anything else... sure made the tcase easy to engage.



The factory manual is hard to read IMO, they intentionally bury stuff so they can get you on warranty stuff unless you have those pages signed... I agree with these guys though, the more often you change the better off the truck will be, but your pocket book will definately be lighter...



steved