Getting ready for a long 3K trip towing out travel trailer and changed out all the fluids over the last two weeks.
This last weekend, I drained the rear diff and was pleasantly surprised how clean the fluid was! I orig changed it out over a year ago and went to the Mobil 1 Synthetic. The origional lube was cooked and black from just one towing trip and the diff cover paint had cooked off!
Since then, I have logged a few thousand towing miles and thought is was time again. Just a little gunk on the plug, but otherwise is was not bad. Also had a driver's side alxe seal replaced under warranty before the change.

I'm with ya 100% on that!

I will be changing my Rear Diff. Fluid this week. I want to confirm that the fluid to use is 75-140 just shy of 3 bottles? I am going to use Mobil 1 as I do in my block.

Not trying to hy-jack your thread but thougth now was the time to inquire since it seems to be a hot topic.

Thats what I used, and have had no problems. I did upgrade the diff cover very early on to the newer OEM finned.

I will be changing my Rear Diff. Fluid this week. I want to confirm that the fluid to use is 75-140 just shy of 3 bottles? I am going to use Mobil 1 as I do in my block.

Not trying to hy-jack your thread but thougth now was the time to inquire since it seems to be a hot topic.
yes 75-140 is the right weight.And it takes like 2 bottles plus a little more than half of the 3rd one.

i believe it barely takes half of the 3 bottle. I put in about a 1/4 of the third and it started pouring out the fill hole

I just checked with my local dealer and they want $85.99 for the Rear Diff Fluid Change...$21.50 / Quart! I'll change it myself.

Super easy to change. Easier than an oil change! I used about 2 2/3 bottles. The front diff was a little more involved, I had a fluid transfer pump that made it easy to get in there.

Getting ready for a long 3K trip towing out travel trailer and changed out all the fluids over the last two weeks.
This last weekend, I drained the rear diff and was pleasantly surprised how clean the fluid was! I orig changed it out over a year ago and went to the Mobil 1 Synthetic. The origional lube was cooked and black from just one towing trip and the diff cover paint had cooked off!
Since then, I have logged a few thousand towing miles and thought is was time again. Just a little gunk on the plug, but otherwise is was not bad. Also had a driver's side alxe seal replaced under warranty before the change.Mine was the same way after 30k the rear diff. oil was as clean as new. I went back with lucas synthetic.

you all must be parking on an angle to get that much fluid in there.

Guys, this is one of the easiest mods to do on your own. Just stop by your local auto parts store and get one of those fluid caps with the hose and a twisting valve (maybe $3 at most).

I ran Amsoil and loved it.

With the Stillen larger diff cover, you can fit exactly 3 qts (maybe a couple of drops less).

I think the differentials with the aluminum covers hold a little more fluid than those with the steel covers. The steel cover units hold 2 1/8 Qts of fluid.

I just checked with my local dealer and they want $85.99 for the Rear Diff Fluid Change...$21.50 / Quart! I'll change it myself. my dealer told me $250 and it takes them 4 1/2 quarts!! i told em bit me and did it myself. little over 2 qts and did a way better job than they are capable of. put tephlon tape on drain plug and fill plug for extra insurence. BTW the diff fluid aint cheap! around $19+ per bottle

btw i hhave the aluminum stock cover

It takes two quarts and then 10-12 ounces out of the 3rd. Mobil one here is $15 a quart.

After you put the nex in there, let the tires turn a few times and recheck it before you put teflon tape on the drain plug and close her up for good.

my dealer told me $250 and it takes them 4 1/2 quarts!! i told em bit me and did it myself. little over 2 qts and did a way better job than they are capable of. put tephlon tape on drain plug and fill plug for extra insurence. BTW the diff fluid aint cheap! around $19+ per bottle

btw i hhave the aluminum stock cover

i would love to know how they squeeze 4 1/2 quarts in there. I also used a little over 2 qts to fill with the aluminum cover.

I think it was a slip of the tongue. The diff takes 4 1/2 pints, not 4 1/2 quarts.

i believe it barely takes half of the 3 bottle. I put in about a 1/4 of the third and it started pouring out the fill hole Yes that's right.

Royal Purple at $12 a bottle. Stuff works great !!