75W90 for extreme use? Are they all the same?

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ringmaster

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Yes I searched over all the old posts
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I need a 75W90 gear lube for the differential in a BMW (clutch type LSD) that has twice the original power going through it (480hp vs. 240hp) and will see abuse at the race track, etc.

My initial thought are one of the following:
Amsoil Severe Gear 75W90
Royal Purple Max-Gear 75W90
Redline 75W90

The RP is the heaviest weight but I don't know if that hurts or helps in high temp applications? The Amsoil seems to be focused on extreme conditions but that might just be marketing?

At the end of the day is there really a difference between all these top-drawer oils? Is it possible that over 100k of use I will see improved performance or durability with one vs the other?
 
I threw in some Mobil 1 to "flush" out my tranny. I wonder what's in the Amsoil. I honestly would recommend the Schaeffer's since it has moly & antimony in it.

Also try Specialty Formulations here
 
I recently put Mobil 1 75W90 in my wife's BMW and so far it works fine. My Amsoil rep did not recommend Amsoil in the BMW.
 
Have you considered Redline's line of ShockProof gear lubes? Here are some quotes from their website regarding that product:

"A unique lubricant containing a suspension of solid microscopic particles as an extreme pressure agent--unique solid dispersion which cushions gear teeth to help prevent tooth breakage and allows the use of lower viscosities.

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."
 
I ran Amsoil's Series 2000 75W-90 in mostly stock (engine wise) BMW's on the track with no issues at all. I'm switching to the new Severe Gear when I get the ready for this season.
 
Redline also has a heavy shockproof rated at 75w250. My son is running this in his new differential after the previous unit locked-up at 60+mph.
 
Oldman - I know why you Amsoil guy said not to use Amsoil gear oil the BMW - it has nothing to do with the robustness - the MOTOR product guide says BMW diffs take a GLS (Factory special lube). If you put M1 in and it works fine, the SVG would work nicely.

The caller here is specifically asking for a 75W-90 and I say the Amsoil Severe Gear oil will work great for his request.
 
Ringmaster, I'm putting out simular power (408 rwhp and 422 rwtq)from a '97 Camaro that weighs 3720 lbs. w/ me in it. The 10 bolt, torsen rear end is not considered strong enough for those power levels. I don't drag race or drop clutch the car, but i will take advantage of the fun factor from time to time. I'm not an engineer but i looked at the design of the differential,gears, axles and bearings and detemined that the weakness in the rear for me was not the pinion or gear ring. The problem would be the axle bearings as the torque of the motor presses the axles against them. I went 130,000 mile (total of 179,000 miles)on that 10 bolt before the axle bearings ( interestingly, the passengerside was much worse than the driver's side) finally gave up the ghost this past weekend. I used Redline Heavyweight Shockproof year round. From time to time I would try, Royal Purple 75-90, Redline 75-90 and Schaffer's 80-90 # 267(?). I always went back to the Heavyweight due to noise reduction ( slight gear whine).I can't say that a particular gear oil matters when you are slamming and/or pressing the torquing axle against those bearings. In time, they will go. IMHO...
And, what do have going on in that Bimmer to put out those numbers??? Very nice!!
cheers.gif
 
quote:
MolaKule, thank you for the reply. I know nothing about the Specialty products but I am open to new ideas. Could you please tell me, via PM or publicly, how this product might compare to the Amsoil, Redline, etc?
Click to expand...
I don't get into biding wars or trash competitors.

I believe (and of course realize this is coming from a biased source) that the SF GL's are a higher viscosity fluid for better elastohydrodymanic lubrication of bearings and resistance to shock loads, more robust EP package in terms of longevity and lower wear, better corrosion and rust protection, and is a full synthetic because I know exactly what is in it.
 
quote:
Originally posted by carl97ss:
Ringmaster, I'm putting out simular power (408 rwhp and 422 rwtq)from a '97 Camaro that weighs 3720 lbs. w/ me in it...
Click to expand...
Thank you very much for the reply. This is exactly the type of real world feedback that I was looking for and your experiences seem to make sense. I will be happy if my diff lasts 130k and I am sure a high quality synthetic will help in this regard
smile.gif
 
quote:
Originally posted by Pablo:

The caller here is specifically asking for a 75W-90 and I say the Amsoil Severe Gear oil will work great for his request.
Click to expand...
It is my understanding that the older ('92-'98) 6cyl BMW LSD diffs require a 75W90 and I have always used the Redline 75W90...hope this is correct
smile.gif


I too thought the Severe Gear looked good but I am really new to all of this!
 
quote:
Originally posted by MolaKule:
Also check out:

http://www.specialtyformulations.com/index_files/Page1458.htm

This is a full synthetic 18 cSt HD GL5 oil.

BTW, even though they are competitors, Schaeffer's Blend (partial synthetic) #267 is a very robust oil as well.
Click to expand...
MolaKule, thank you for the reply. I know nothing about the Specialty products but I am open to new ideas. Could you please tell me, via PM or publicly, how this product might compare to the Amsoil, Redline, etc?
 
I thought that BMW LSD's req'd Castrol SAF-XJ which is a 75W-140 synthetic. That's what I use.

Not a 75w-90.
 
quote:
Originally posted by Dr. T:
I thought that BMW LSD's req'd Castrol SAF-XJ which is a 75W-140 synthetic. That's what I use.

Not a 75w-90.
Click to expand...
Dr. T, this is news to me, where did you get the 75W140 spec from? I am looking for oil for the "medium case" diff as found in '92> E36s and some others.
 
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