Diff Oil Weight Question
Thread Starter
JK Newbie
Joined: May 2007
Posts: 45
Likes: 0
From: Plainfield, Illinois
Diff Oil Weight Question
Hey guys....need some advice here!
I went to the local auto store today and realized when I got there that I forgot to check the weight of the oil used last time I changed my diff fluid. I didn't drive the jeep there so I couldn't check the owner manual...So I asked the guy at the store. He checked the computer and recommended 75w25 (can't remember the last number but think it was 25) plus some additive stuff.
So, I got the new covers on this afternoon, checked my maintenance log and realized I used SAE 80w20 last time. I called Jeep and they also recommended SAE 80w20 unless I was towing, which I'm not. I asked about the additive, the guy asked for my VIN# and said I didn't need it.
I was telling my friend about this and he seems to think I need the additive becuase of my limited slip/lockers. What do you guys recommend?
As much as I want to gear up, it's not in the budget right now! So I need to make sure I do the right thing with the diff!
I have a 2007 4 door Rubicon....I appreciate the help!
I went to the local auto store today and realized when I got there that I forgot to check the weight of the oil used last time I changed my diff fluid. I didn't drive the jeep there so I couldn't check the owner manual...So I asked the guy at the store. He checked the computer and recommended 75w25 (can't remember the last number but think it was 25) plus some additive stuff.
So, I got the new covers on this afternoon, checked my maintenance log and realized I used SAE 80w20 last time. I called Jeep and they also recommended SAE 80w20 unless I was towing, which I'm not. I asked about the additive, the guy asked for my VIN# and said I didn't need it.
I was telling my friend about this and he seems to think I need the additive becuase of my limited slip/lockers. What do you guys recommend?
As much as I want to gear up, it's not in the budget right now! So I need to make sure I do the right thing with the diff!
I have a 2007 4 door Rubicon....I appreciate the help!
JK Enthusiast
Joined: May 2009
Posts: 356
Likes: 0
From: Charlotte, NC
You may want to read this article: http://project-jk.com/jeep-jk-write-...hange-write-up
Most of us run synthetics - and syns do not require the use of an additive. That said, 75W/90 or 75W/140 are very common. The manual states 80W/90.......not sure where you are seeing 80w/20
...........but that's just not right.
I think you'd be well served to go get some Mobil1 75w90 (or 75w140 if you wheel hard or tow) and put that in ASAP....I hope you arent running 80w/20.
Most of us run synthetics - and syns do not require the use of an additive. That said, 75W/90 or 75W/140 are very common. The manual states 80W/90.......not sure where you are seeing 80w/20
...........but that's just not right.I think you'd be well served to go get some Mobil1 75w90 (or 75w140 if you wheel hard or tow) and put that in ASAP....I hope you arent running 80w/20.
JK Enthusiast
Joined: Jun 2009
Posts: 389
Likes: 0
From: MA
JK Jedi Master
Joined: Mar 2007
Posts: 14,800
Likes: 374
From: Midwest City, OK
First, which do you have, LSD or lockers? Second, if you go with the recommended synthetic lube, you should not need the additive (assuming you have LSD). If your rear axle starts to chatter, then you can put in the additive. If you have lockers, I don't believe there's any special additive for that (someone smarter than me please confirm).