AmSoil mixture in Subaru Differential

[Titan]

Put the spec'd 75-90 gear lube in the rear differential of my Subaru, used AmSoil Severe Gear. I noticed it whined more than what was in it before. No big deal, just a little more whine on light accelleration that was noticeable from 25-45 mph. During a discussion with someone about viscosity, I looked up the MSDS info on a standard convential lube and the AmSoil. Found that the AmSoil was thinner from at least 40-100 degrees. So, I drained 1/4 of the lube, and replaced it with AmSoil Severe Gear 75-140. Whining is MUCH attenuated. I don't think the whining was hurting the differential, but, I like it quieter.

 

[Pablo]

I mostly recommend the SVT 75W-110 for Subie diffs for this reason - http://www.lubrizol.com/products/automotive-gear-oil/J306.asp

You see the specifications changed and Subaru is not alone in not keeping up. This is why when you compare a new 75W-90 with olden days 90's the more modern lubes have a lower viscosity. (Aside from the fact that a full synthetic flows much better at cold temps) Your blend is fine.

 

[Bill in Utah]

Interesting... (as he has a few quarts of 75-90 of the Amsoil ready for the Outback Diffs)

I guess we will find out next week how mine does with the lube..

Bill

 

[Titan]

Originally Posted By: Pablo


You see the specifications changed and Subaru is not alone in not keeping up. This is why when you compare a new 75W-90 with olden days 90's the more modern lubes have a lower viscosity. (Aside from the fact that a full synthetic flows much better at cold temps) Your blend is fine.


Very nice. Thanks for the update, as well as the "Okie-Dokie" on the blending I did. Bill, you might want to pick up a quart of the 75-140 and mix with your 75-90, as your differential is the same as mine. It really is quieter than the straight 75-90. And although the car I bought the 75-140 for isn't anything like a Subaru, it came with 80-90 in it, and the 75-140 doesn't knock it's mpg down enough to measure.

 

[Pablo]

I probably was a bit unclear in my post - the new 75W-90's are not thinner than the old specification. As you can see in the table - The new spec. 75W-90's just occupy the "lower half" of the old spec. viscosity range.

Bill if you are uncomfortable with 75W-90, let me know - I'll send you some 75W-140 for blending. Many, many people are using 75W-90 in Subaru's with no issues or noise, it's a bit of the luck of the differential clearance draw. Frankly it was not enough of a niggler for me to divert you from the 75W-90.

 

[Bill in Utah]

Originally Posted By: Pablo
I probably was a bit unclear in my post - the new 75W-90's are not thinner than the old specification. As you can see in the table - The new spec. 75W-90's just occupy the "lower half" of the old spec. viscosity range.

Bill if you are uncomfortable with 75W-90, let me know - I'll send you some 75W-140 for blending. Many, many people are using 75W-90 in Subaru's with no issues or noise, it's a bit of the luck of the differential clearance draw. Frankly it was not enough of a niggler for me to divert you from the 75W-90.


I'll send you a PM.

Thanks!
Bill

 

[Titan]

Just did the extract/refill with 300 cc's of the 75w140 in the transfer case...NOW the Subaru is very quiet. This is a car that I drove 49,000 miles last year at highway cruising 99% of the time. My other Subaru only has 28,000 miles in two years, it doesn't whine, and it still has the 75w90 in it. So, some whine and some don't, but, going a bit thicker sure cured the whiner!

 

[Bill in Utah]

Titan,

I put in the Amsoil in the front when I bought it last December but waited till last month to put in the rear.

Just got back from a short trip to Moab in the Subaru and yep, its got a little whine in the rear diff. (louder when going down hills with foot off the gas)

I'll have to add some to the mix and hopefully get rid of it.

Pablo, Amsoil may just want to change their recommend for Subaru's to 75-110 just to be safe.

How much to add? (I see 300cc did the trick for you) While I'm at it I think I'll also add some 75-140 to the front one too.

Paul, I'll PM you.

Thanks Bill

 

[Pablo]

PM sent. A quart of 75W-140 should do it.

 

[Titan]

Just an update, I drained a bit more of the 75-90 mixed with 75-140, and replaced it with more 75-140. Now, the rear is nearly silent! I estimate I've about half 75-90 and half 75-140. I agree a full load of 75-110 might be perfect.

Interestingly enough, on my other Subaru, it's very quiet at 100% 75-90...but, it doesn't spend 99% of it's life at 70-75 mph, either. Don't know if that has anything to do with it....but, the two rear differentials really react differently to 75-90.

 

[Pablo]

I shipped Bill a quart. The rear only holds 1.7 pints, so he should easily get it 50/50 with about 14 oz of the 32 oz and use the rest in the front. (or just drain out a pint and add a pint....

)

 

[Titan]

Originally Posted By: Pablo
I shipped Bill a quart. The rear only holds 1.7 pints, so he should easily get it 50/50 with about 14 oz of the 32 oz and use the rest in the front. (or just drain out a pint and add a pint....

)


Sounds perfect to me!

 

[bluesubie]

Good discussion! I went with Long Life since it has less friction modifiers, but I'll be switching to Severe Gear since I'm not so happy with LL in cold temps.

My Michelin Pilot Sport All-Seasons are so noisy, I wouldn't notice rear diff. whine anyway.

Bill - you mention adding some 140 to the front. There's a guy on nasioc that races a 2.2L Impreza. He went with 75-110 front and rear and is very happy with it.
http://www.jameswilsonracing.com/

From his nasioc post:
Quote:
Made the switch to the AMSOIL Severe Gear 75w-110 gearbox and diff oil today. Holy [censored]! Nice smooth shifting, about half the gear noise (even my passengers commented, "what did you do to this thing?"), and should take the abuse.

-Dennis

 

[Bighank]

Has anyone else used the 75w-110 Severe Gear in a manual
transmission?

 

[bmwtechguy]

I used the SVO 75W-140 in a noisy gearbox in my truck til I could get time to rebuild it. It did shift a little stiffly at first in the morning and I had to make a point of shifting it carefully then, but when warmed up it was very quiet and much smoother than the 75W-90 that was in it. And yes, it protected my gearbox quite well from grenading until rebuilt. Now I'm using the GL4 75W-90 stuff called MTG and it shifts perfectly hot or cold. Much better than the 10W-40 engine oil that is spec'd for it.

 

[Bill in Utah]

Originally Posted By: Pablo
I shipped Bill a quart. The rear only holds 1.7 pints, so he should easily get it 50/50 with about 14 oz of the 32 oz and use the rest in the front. (or just drain out a pint and add a pint....

)


And EXCELLENT SERVICE arrives on my doorstep from the man in the brown truck!

I'll get to it this weekend and see first if we can quiet the rear end.

I'll report soon.

Thanks Pablo! You are the man.

Bill

 

[bmwtechguy]

That is great service, I gotta say. Be nice if more dealers (of any product) would offer that level of service to make a customer happy. A satisfied customer will probably be back again. Looks like Pablo will do what it takes. Congrats!

 

[Bill in Utah]

Bad Bill!

(Did not post my results here in a fair amout of time.. No excuse but had my mind on other "operations")

Pablo did ship me a quart (Thanks again Paul for the EXCELLENT SERIVCE!) and I did pull out 1/3-1/2 or a quart in both front and rear and in went the 140.

Cleared it right up. Quiet as can be and glad I'm ok for as long as I want to run the fluid.

Next time (I'm going to stay with a 50-60k drain/fill OCI on the diffs) I'll just order the 110 straight up.

Gas should only be $10-$12 (if avail) at that time...

Thanks again Pablo!