75W-90 and a 75W-140 mix??

[AP1_F20C]

I'm about to change out the differential fluid on my Honda S2000 and, while it calls for a 75W-90 gear oil, I'm considering doing a 50/50 mix of 75W-90 and the 140. Living in a warmer climate than most of the rest of the country I figured it would be better to have some added protection, especially during the summer.

Does anyone object to this? Any pro's and/or con's from doing this?

Now for my real question...Redline or Schaeffer's?

Also, does Schaeffer's make a manual transmission fluid? If so what is the number?

 

[Ken2]

SAE 90 is a broad viscosity spec. I'd look for a brand with higher viscosity within the 90 wt. range. Or, just buy a top quality brand that offers a superior additive package and higher film strength due to the better base oils...Schaeffer #267 or Red Line.

Schaeffer's manual transmission oils are for truck transmissions and come in 5 gallon pails and larger...#239S-50 wt. & #742.


Ken

 

[Doug Hillary]

Hi,

perhaps you should consider a synthetic 75w-90
It is a better alternative than any mixes

Regards

 

[AP1_F20C]

I'm leaning towards Redline for my differential fluid but I'm curious.

Would the added moly in the non-synthetic Schaeffer's be more beneficial than the Redline or would the fact that the Redline is synthetic be more of a bonus over the moly?

As you may be able to tell...I'm indecisive.

 

[AP1_F20C]

Doug,

I have been using synthetic. So far I've only used the Mobil 1 75W-90.

What I'm talking about is a half and half mix of Redline's 75W-90 and their 75W-140.

Would it be ok to do this in a diff that typically calls for the 75W-90 is my question?

 

[Doug Hillary]

Hi,
Why would you want to?
Modern differentials are extremely robust and IMHO they even run very cool in normal operation

50 years ago diffs lasted for
A synthetic 75w-90 GL5 lubricant is a very good piece of modern chemistry - whoever makes it. Take a look at a few Makers's Product Data sheets to see how advanced they really are

We regularly get up to 1m miles out of heavy truck diffs -550hp and 42500kg- with only a couple of oil changes in that time - on the same synthetic 75w-90 GL5 lubricants
A wheel bearing or a wheel seal or two may be the only failure in that time

Regards

[ January 09, 2004, 06:03 PM: Message edited by: Doug Hillary ]

 

[MolaKule]

There is NO advantage to mixing gear lubes.

Choose a good 75W-80W90 blend or a 75W90 Synthetic.

 

[Robbie Alexander]

quote:

---

Originally posted by AP1_F20C:
-*-*-*
Does anyone object to this? Any pro's and/or con's from doing this?

Now for my real question...Redline or Schaeffer's?

Also, does Schaeffer's make a manual transmission fluid? If so what is the number?

---

NOPE! I would not mix.
What you want to do is upgrade to the thicker one once the gears start to get loose, you may benefit my that, but I'd stick exactly what the weight the mfg says!

Redline or Schaeffers.... Hummm, toss a coin, soesn't matter. I am not saying they are equal but they both will get you past the 30K for warranty work. After warranty, I'd leave the puppy (either one) in there 100K+ maybe 200K, on some 250K+....
The application in gears is one application that SYN's probably do measure up better than dinos, just for the fact that they can get into crannies where dinos cant go, other than that syns may have a little more life but IMO not much here, if they are both quality lubes, but then again there are not that many TOP of the line quality lubes.
The ones you are looking at are both fine lubes.

Granted a Fantastic Dino and a VERY good SYN will both get you in the upwards milage I just quoted.

What you don't wanna do is go much past 150-200K without sample or changing because IMMVHO that is about the limit to any fluid in a normal passenger vehicle... OTR tractors can go 500K-800K between drains depending on the quality fluids. These numbers are for a quality fluid.. If you did buy an OTC fluid, I'd for sure stick with 30K changes... maybe 60-100k Tops on some of the Syns.

Moly will not do you any special benefits in your application. Modern lubes are so well constructed, and the modifiers work so well, that you should not go out of your way to spend any time looking for one. They are out there, I even sell one, and they can work well for their applications, but you, just stick with your GL-4 or 5 fluid, or whatever it calls for, and don't worry... If you change it once or twice early
(I went overboard and did 5 times before 100K) then you can usually let the quality ones just run.

 

[wulimaster]

Your fuel economy will suffer from higher weight oils.

 

[Steve S]

75w/90 is all you need especially using a syn. oil.

 

[GeorgeCLS]

Re-affirming what has been previously posted; every tractor trailer you pass on the freeway is running synthetic 75W-90. (well, okay, a few Schaefer 90 weights too!). i.e. NONE are running anything heavier... These are 80,000 pound rigs.. Warranty is extended from usual 100,000 miles to 770,000 by running full synthetic 75W-90.. That is all you need for excellent, longest performance. A 140W will reduce fuel mileage, generate unwanted heat and will offer nothing in the way of increased protection for your application..
George Morrison, STLE CLS