Did a search & read a lot about this topic...

But nobody asked this question - Redline has two products:

75W90 & 75W90NS.

Their website for the first states "It contains friction modifier which is recommended for limited-slip units"

Correct me if I'm wrong, but the manual says no friction modifiers are needed / should be used.

75W90NS - from the web site "This GL-5-type gear oil doesn't contain the friction modifiers for limited-slip hypoid differentials."

Wouldn't the second be the proper choice?

Thanks,

ZS

 

ZS,
I run Valvoline not Red Line but I did call Red Line and talk to them about their recomendation. They said the use 75W90 with the friction modifier. According to them, even though our type of limited slip does not have clutches and therefore does not need the modifier, it won't hurt it and will make the fluid slightly "slicker".
I honestly don't think it matters one way or the other.

The Boss Hog
(Just my opinion . . . . . . )

 

my dealer told me that i had to have the modifier in mine. he also said something 75w-140w sound right to yall I thought something around 90w was about right. Someone chime in and tell me something here.

 

from the '03 Service Manual:

FRONT AXLE
C205F - Mopar Gear Lubricant 75W-90
9 1/4 AA - Mopar Synthetic Gear Lubricant 75W-90
REAR AXLE
9 1/4 - Mopar Synthetic Gear Lubricant 75W-140
10 1/2 AA - Mopar Synthetic Gear Lubricant 75W-90
11 1/2 AA - Mopar Synthetic Gear Lubricant 75W-90

The Boss Hog
(Don't dealers have this manual . . . . . . . . )

 

you never know...., a salesman at my local dealer tried to sell me a hemi cummings.

The Dana's of old called for that heavier lube.

 

I hear a lot about dealers who will say anything and everything - is it to make a sale or just ignorance? I think its a combination of both quite often, and that human characteristic to NOT admit that you JUST don't KNOW!

I know my local dealer is like that - which is why I drove 50 miles to a dealer who gave me good information in e-mail originailly and has treated me good ever since. In fact they went way out of their way to find an existing 03 truck that met my requirements from another dealer 100 miles away in order to get me the 4 year 0% financing that was offered last October (in Canada at least!). They actually had one dealer agree to swap inventory for a truck, then on the day they showed up (a Saturday) to pick it up, were told by the first dealer "Sorry, we sold it this morning!" - I had already signed the papers to buy it!!! Oh well, in the end I got a better truck that I was initially looking for, and they knocked some more of the price because of the first dealer screwing us around.

Also, I was happy to hear from this dealer "I don't know, but I will find out" when I asked some more technical questions - not some BS answer (like my local dealer does).

In any case, I got my answer to the Redline question here & am very glad I stopped by this site a month before I bought my truck last year!

It should be a requirement in the Dodge user manual for all new owners!

ZS

 

I have Redline 75w90 for the diffs, MTL for the 6 speed and +C for the transfer Case all setting on the bench waiting for 15K to roll around so I can put them in.

 

I went to my dealer, figuring I would get the actual DC stuff if it wasn't too expensive, and the guy there told me they also sell redline. He also said that for towing they are now recommending 75-140 even in the 11.5, and this would not void the warranty. I don't have limited slip, but I understand the AA limited slip does not require an additive.

Anyway, the 75-140 redline synthetic seems to work fine so far.

P.S. If you have an early 03, the recommended oil level for AA differentials has apparently been revised from what the owner's book says. Several threads on the subject.

 

Thats what I figured some kind of change. Service mgr. very easy going where I am at. I read the manual Boss Hogg that is why I asked whats up with this 140 weight. Course I didn't ask him about the manual stating 75w-90w for the rearend.

 

I ran that expensive DC stuff and still toasted my rear end. They put a new ring and pinion in it and I am now running Red Line 75W140 in it. Dealer agreed with me that the heavier oil provides more protection for towing heavy. The friction modifier doesn't seem to have hurt the limited slip funcion either.

Casey

 

Hey Jerry R, what is +C
DC calls for ATF+ for the Transfer case, power steering, and auto Tranny.

 

SuperGewl,
Actually I typed it backwards its C+ and it is Redlines ATF for Chrysler products. DC calls out using a ATF in the transfer case that meets ATF+4 specs. Redline C+ meets this and I will be putting it in my Transfer Case @ 15K.

 

I installed Redline 75W90 and have had it in for 10,000 miles now. I got it for the same price as Mobil 1, so I went w/the Redline. Haven't drained the rear end w/redline (for a look at it) yet, but so far it's all good.

BTW, the original fluid didn't look so good just after 3,750 on it.