Differential Fluid comparison and analysis - old vs new, Mobil 1 vs Redline.

"krazik" has sent me some "courtesy" Redline Shockproof synthetic gear oil to try out and give my evaluation. Little did he know what he was getting his product into. This thread will be ongoing and will span several months, so if you are interested, just subscribe to it and you'll see new information as it comes.
Today, I changed out the Mobil 1 synthetic 75W90 gear oil that I've been using quite happily since year one. I put in the Redline and will report on that later.
I thought I'd take the opportunity to show you what it looks like before and after being in the casing for a while. And thanks to "FormerH22a4", who gave me several oil analysis kits, I will be sending the old diff fluid to get done very soon. I shall post those numbers when I get them back.

I'm not going to go into the actual diff fluid change. You can see that here:
http://www.s2ki.com/forums/showthread.php?...&threadid=99995

The Mobil 1 that just came out is the second batch that has been in the diff since my 4.44 gear swap. I have logged 4000 KMs (2500 miles) over 4 months on it with mostly city driving spanning both winter and summer.
Here is what the new Mobil 1 and old Mobil 1 looks like, along with what the magnetic drain plug looks like:
diff fluid - 1.jpg[/PHOTO]
Note the "slurry" stuck to the drain plug. I consider this to be quite normal.
Now see the drain plug after it's been wiped off:
diff fluid - 2.jpg[/PHOTO]

Just got the analysis back on the Mobil 1 fluid:
Mobil 1 analysis.jpg[/PHOTO]
Hopefully, you can see the numbers, but the important thing to me is that all critical assessments are "NORMAL". This is good for me as the car is supercharged and I have been known to "launch" from time to time.

More to follow.

This post is actually done on Sept. 14th. I put it here so you can compare with the first results more easily. It is duplicated on page 4 of the thread.
Well, finally put on 4000 KMs since the Redline went in. This is the same interval as for the Mobil 1. This time, was a fair bit of highway driving, along with several rolling clutch dumps and some spirited driving.
Here's the "wine glass" comparison. The red color makes it hard to see if the "old" fluid (on the left) is that much dirtier than the new stuff (on the right). It is a bit darker. (Sorry, the camera seemed to focus on the background on this one.)
Redline 11.jpg[/PHOTO]
Drain bolt before wiping off (a similar amount of "fuzzing" as with the Mobil 1):
Redline 22.jpg[/PHOTO]
Now the "smear test":
Redline 33.jpg[/PHOTO]
There may have been a slightly bit LESS fuzzing on the drain bolt with the Redline (but this may be attributed to the highway driving - less stressful).

The analysis will be sent tomorrow. Results in a week or two.
I've now gone back to Mobil 1 in readiness for winter.

Sept. 26/03:
The Redline SP oil analysis just came back as follows (you may have to click each pic and choose a larger size to see the numbers):
Redline SP analysis.jpg[/PHOTO]
For ease of comparing, here is the Mobil 1 data sheet again:
Mobil 1 analysis.jpg[/PHOTO]
Although both fluids were used for the same amount of miles and under similar driving conditions, the Redline analysis indicated that there is noticeable wear and that the fluid was no longer serviceable. For my type of driving, I will stick with Mobil 1.

I just changed my diff with 7K miles with Redline Gear oil. What's "shockproof?"

http://marketplace.s2ki.com/s2ki/customer/...3&cat=24&page=1

The marketing people say

If you search there are a couple threads about it.

But in a nutshell it's designed to not throw off the gear as easy and take shockloading a lot better. You know... those occasional stoplight launches a lot of people take.

Xviper, after seeing the Mobil1 after 2500 miles, I feel that I need to change my Mobil1, now. It hasn't been in the differential 15,000 miles yet, but I'll bet it's really black by now.

I don't doubt it one bit, however, I'm not sure that it being black like that is all that bad for the diff. I just do the change every year 'cause it makes me feel good about the way I take care of the diff.

Oh and "RARE M5", here's what the bottle looks like:
Redline 1.jpg[/PHOTO]
Redline 2.jpg[/PHOTO]

Boiler, I don't pretend to be an expert, so I may be wrong. But there is nothign wrong with oil being black. It is supposed to be. You could change your oil every 500 miles and it will still be black. That's what it does. Obviously, since XViper last changed his diff oil 2500 miles ago, it has turned black in less time than that. Common sense tells us that you do not need to change diff oil more often than every 2500 miles.

That being said, I am a bit of a fastidious about maintenence myself, and although I make diff oil/ tranny oil changes every 30k, 15k does not sound unreasonable, especially if the car is tracked.

Please don't misunderstand my intentions. I would never have changed out my diff fluid at this time. I only did it so I could begin my evaluation of the Redline fluid as per krazik's request. I shall also dump the Redline after about 2500 miles so the comparison can be more valid.

Nice presentation with the wine glasses

I love Redline Shockproof. Mostly for subjective reasons, like smoother running, improved lockup (which I can't explain on a gear type LSD), etc.

I've run the heavy duty and the lightweight. Both work well, but the lightweight seemed to "go away" quicker. Its heavyweight only for me now. Didn't know the store carried it. Guess I'll be shopping there now.

UL

My wife insisted. She wouldn't let me use brand new sperm specimen cups.

Does the Shockproof have similar detergent properties as some of the other fluids that are available to us?

Pepto-Bismol

Will the shockproof work in a clutch type of lsd?

BTW, UL has a bunch more of the specimen cups if you need them

Will the Kaaz/other clutch types work w/ standard 75W90 gear oil?

From Redline site http://www.redlineoil.com/frames/gearoil.htm Under friction modifier.

xviper, will you be doing a review on this Reline for the S2k transmisison as well?

krazig, is it safe to use this oil for the S2k transmiision? Could xviper do a review on this as well?

TIA

Mmmm not that important still, info most people will be interested to learn, what's the price between the two lubricants???

I have had the opportunity to use these and other lubes. It seems to me that although heavy shockproof may offer some extra protection the price paid for that is some small additional operating losses due to the viscosity. Since I have never heard of wear problems with these units I chose to use regular RL 75W90 gear lube (RL recommended choice for our car and street use) on the theory that it is adequate protection with less loss (and it feels the same from the drivers seat). I will be interested in hearing your opinion of the heavier lube, especially in your cooler clime.

Subscribe...

Although the rated viscosity can be pretty high, the cold viscosity is still 'normal'. There is also low internal fluid frction, for little power loss.

"The Heavy can be rated as a 75W250 Gear Oil, but has the lower internal fluid friction of an SAE 75W90. The LightWeight can be rated as a 75W140 Gear Oil, but has the lower internal fluid friction of an SAE 30 motor oil. The SuperLight can be rated as a 70W90 Gear Oil, but has the lower internal fluid friction of an ATF. These ShockProofTM lubricants provide much greater viscosity in the thin layers between the gear teeth, but have very low internal fluid friction, which means very little power loss for the protection achieved."


There is "a low viscosity when cold" per RedLine.

I understand all of that, but I have pumped it in and drained it more than once and can tell you that even in 100F it is substantially heavier than the the normal 75W90 gear lube. Maybe it is the shockproof additive, or my imagination, but we will let xviper give us his impression.

I'm all ears.

Kendall diff oil (the one w/ friction modifier added) works great w/ a KAAZ .......... I can take a picture of the bottle if you want.

I'm not sure about this, perhaps krazik or someone else can answer. You do realize that the Torsen LSD on the S2000 has no clutches, right?

I'm not sure I want to put this Shockproof fluid into my tranny. It's really thick coming out and my car does run in -30*C temps. I may not be able to move the shifter on cold mornings. Let's get one thing done at a time. The Honda MTF works quite well for me through all 4 seasons. Maybe next spring, if krazik has an appropriate tranny fluid he wants me to try, I give it a go. That's when my next tranny fluid change is anyway.



cdelena, I don't know if I will run into "cold" weather before I get my next 2500 miles on the car as I tend to log more miles during the summer "vacation" time than I have up till now. However, I will let you know about it down to as cold as it will get.

So far, I feel no difference after one day of driving but then, I didn't really expect to. The diff is so far behind me and isolated that the butt dyno has a hard time discerning a "good" running diff from a "very good" running diff and mine was running just fine before with Mobil 1.

(If I don't answer anyone's questions, it's because I don't know and hopefully, some of the others will chime in with one.)

Xviper,
I like the wine glass presentation... very classy!
Tron1