08 LGT 5-spd - 9.5k miles - Changed trans to AMSOIL 75w110

Hi all,

This past weekend I ordered 5 quarts of AMSOIL 75w110 Severe Gear to do my trans and rear diff. I'm writing this post to provide information on why someone would choose to do this to their Legacy GT 5-speed.

The Job

Before I go any further, I want to give a big thank you to Inigo Montoya for his DIY write-up on changing the trans fluid in this car:

www.legacygt.com/forums/showthread.php?t=94834

Thanks to him, I knew I had the right tools and the know how to get the job done quickly. It took me about 5 minutes, total, to jack up the car, squeeze myself under there and drain the old trans fluid after driving it around for 2 minutes. It took about 20 minutes to drain to a point where I was ok plugging it back up. It took another ~20 minutes or so to fill up the trans....imagine putting 4 quarts of warm maple syrup down a 1/2" wide tube. So this job is a piece of cake, but put aside 45 minutes to an hour to do it right....simply to allow draining, fill, and careful measuring and topping off of the trans/front diff.

Costs & Tools:

AMSOIL 75w110 w/ AMSOIL preferred customer discount = $44 + ~$5 in shipping

T-70 Torx Bit = $8 shipped ordered online

Funnel w/ long 3/8 ID tube = $1.79 at Walmart

I already had the jack, jack stand, 1/2" drive ratchet, rags, and oil pan to do the rest of the job. Oh yeah, and a phillips head screwdriver to remove the engine cover.

Background for using this Fluid

Anyway....before I get into the review: Why AMSOIL? Why 75w110?

First, 75w110 is a new viscosity rating for fluids that were at the higher end of operating temperature viscosity 75w90. Here's a great link that shows the difference:

http://www.lubrizol.com/products/automotive-gear-oil/J306.asp

To sum-up....old 75w90 rating had a kinematic viscosity rating range at 100 degrees celcius from 13.5 - 24.0 (lower is less viscous). The new rating means 75w90 is between 13.5-18.0 and 75w110 is 18.0-24.0

So 75w110 is the equivalent of an 75w90 that had a higher operating temperature viscosity....in AMSOIL's case, it's about ~20 on that range.

For those worried about cold viscosity....that range is for operating temperature. AMSOIL 75w110 has a lower cold pour point than Subaru Extra-S. It's actually more fluid at lower temperatures according to the viscosity ratings.

But that doesn't explain why AMSOIL? Well, I did this to help provide a benchmark for others. I'm a big fan of AMSOIL, having used it in my 06 Civic SI engine and trans to great benefit. Many people have tried Subaru Extra-S, Uncle Scotty's Cocktail, and other fluids. A few people have tried AMSOIL 75w90 (bear in mind they have 3 different versions) with some good reviews and one or two poor reviews....but frequently the user didn't specify whether they used AMSOIL 75w90 long life, AMSOIL 75w90 severe gear (new), or AMSOIL 75w90 Manual Transmission & Transaxle Gear Lube. Each is a unique lubricant.

So I decided I wanted to risk my money on a newer lubricant, a full synthetic lube, a more viscous lube at operating temperature, a name brand not too often used in Subaru's (AMSOIL), and just provide a comparison point.

The Review

Let me be clear: Extra-S set a high bar based upon reviews. People universally claim smoother shifting, no or less reverse lockout, good cold weather operation. So I had high expectations. I wanted AMSOIL Severe Gear 75w110 to remove gear/syncro whine, quiet the drivetrain down, allow me to comfortably shift much faster at mid-range rpm operation, remove some of the shifting notchiness/clunkiness, and remove most if not all times I would be locked out of reverse.

It's been about 200-250 miles and 4 days since I did the change. Unfortunately, I have nothing colder than 50 degrees to comment on, but I'll provide updates.

Reverse lockout is pretty much gone. I haven't experienced it yet. This morning, on the first shift (going into reverse) when the car was completely cold...it went into reverse with a really satisfying sensation and no notchiness or "pushing metal out of my way" resistance.

Overall shifting is smoother. It's no 06 Civic SI/Acura RSX Type-S/Honda S2000/Acura TSX shifter....but it's not going to be. But I no longer feel like I'm hurting my transmission....it feels much more natural and right. Slow shifting, fast shifting. It feels like the transmission doesn't mind anymore and it feels protected. It's hard to explain. AMSOIL claims the lubricant provides an "iron sulfide barrier" on the metal...it kinda feels like there is some protection on there.

The drivetrain is definitely quieted down. I don't know how to explain it exactly. The engine still sounds the same and has a little drivetrain lash upon sharper engine braking...but the trans whine/gear whine is pretty much non-existent. It's really nice....and I feel like going with Hogzaust Stage 1 will help cover up the untoward engine lash with a nice exhaust sound

Shifting at 4000+ rpms is much smoother and quicker. The gears engage faster. There is a split-second of syncro whine I can still feel/hear....but it's much LESS in noise and time spent hearing it.

At this point, I'm pretty happy. I wanted the transmission to feel "safe" from my everyday shifting, and it feels that way now. I won't worry about wearing out syncros anymore. Based upon reviews, i think Extra-S might smooth out the shifting a little more than I've experienced....but I can't really tell, now can I?

I would definitely support anyone choosing to go with this fluid at this time. I think winter (i.e. 10 degree) operation will be much more telling and I'll provide updates when that time comes. But for now, I'm satisfied.

I hope this post helps others in their choice. I think Extra-S is a great choice, especially now that the King of Parts sells it for $55 for 5 quarts. Personally, I'll probably try it in 40-50k miles. But I'd say Extra-S or AMSOIL 75w110 Severe Gear are both near equal cost gear lubricants, and while Extra-S offers alot more reviews with great satisfaction in shifting quality, AMSOIL probably provides a more robust lubricant to stand up to extreme stresses. So you really can't go wrong

Joe

Hey Nemo,

I disliked the way the trans felt when shifting and I wanted to get the stock fluid out of there as soon as possible.

Two things about the stock fluid change:

1. The stock fluid looked brand new when it came out

2. The magnet on the drain plug didn't look bad when it first came out. But I didn't realize the blackness that covered it was the equivalent of metallic sand. I COVERED a disposable rag in the black metallic particles I wiped off the magnet. I was impressed.

If you wanted to go a cheaper route, the Supertech 75w90 talked about in another thread might be a good route. Seems like changing the trans fluid out fo the 5-speed as soon as possible is a good idea for simply driving enjoyment. And cost shouldn't be an obstacle.

Joe

I have the same issues with how my 08 tranny feels when shifting. I just wasn't sure if there was a reason for changing it (and the rear diff) so early.

Maybe I'll do this this weekend.

I've only done the trans so far so I could accurately gauge the independent effects (oh yeah, and it my was 3-year wedding anniversary weekeend and my wife and I were going out...).

I looked at the rear diff and I think I might be able to change it on flat ground without jacking up the car.....it looks pretty accessible from the rear....

If now, maybe just jacking it up a few inches. Does anyone know if you can jack up from the rear tow hook mounting area?

Joe

NoooooOOoo....I can't jack on any critical points! I've been programmed not tooo!!!!

Ok. I'll do it flat or jack the rear diff (I don't think my $20 pepboys jack can reach the rear diff and still have room to pump the handle, but hey....).

NoooooOOoo....I can't jack on any critical points! I've been programmed not tooo!!!!

 

Ok. I'll do it flat or jack the rear diff (I don't think my $20 pepboys jack can reach the rear diff and still have room to pump the handle, but hey....).

I understand .

I have a piece of 3/4" plywood cut to fit that I put between the jack and diff. No worries.

hehe....I'll grow-up and do it. Or I'll drain the rear diff without jacking....it seriously looks possible. The only difficult part would be not being able to put adequate force on the half inch drive to loosen the plugs. But that's what legs and feet are for....

Joe

Well, if it's on flat ground and un-jacked, then no. And, honestly, I think I could just jack up the diff and fill it without it being level.

It's a splash type diff and would have, maybe, an extra .05 quarts in it from being jacked from the diff. It would not be low, that's for sure.

Joe

Additional info: AMSOIL 75w110 Severe Gear and Redline 75w90 have about the same Brooksfield Viscosity rating at -40 degrees celcius....so they should be about the same in comparison at very low temps.

Brookfield vis at -40 degC:

AMSOIL 75W110 Severe Gear: 118,500

Redline 75W90 GL5: 110,000

AMSOIL 75W90 Severe Gear: 68,150

Thanks. I've heard from people more knowledgeable than I that the 110,000 vs. 118,000 is Gala apples vs. Macintosh. So I'm assuming the difference in feel at very cold temperatures is going to be nil, between those two. I don't know how Extra-S rates.

Joe

AMSOIL claims the lubricant provides an "iron sulfide barrier" on the metal...it kinda feels like there is some protection on there.

 

I would definitely support anyone choosing to go with this fluid at this time. I think winter (i.e. 10 degree) operation will be much more telling and I'll provide updates when that time comes. But for now, I'm satisfied.

 

Practically all EP gear lubricants have some sort of sulphur based additive. The fact that AMSOIL makes a big deal of this worries me as it is usually an indication that they added a lot more of the additive. This is great for gear face wear but not the best for copper alloy life. Don't get me wrong, I like AMSOIL lubes, just not in the gearbox. My experience with SVG 75w90 was very bad once it got cold. Near freezing you couldn't even put the car in gear. The shifts felt great at higher temps, they were a lot less "scratchy", but the cold performance was terrible.

Yeah, the scratchiness is gone in all gear shifting....I like that, the word scratchiness....it defines well the stock characteristic I was seeking to suppress. So far, in temps down to 50, the AMSOIL stuff is the same or better than stock.

From what I can see, AMSOIL 75w110 has a brooksfield viscosity damn near identical to Redline 75w90. I've seen plenty of redline users compliment the cold shifting characteristics in their subarus, so I'm hoping for the same here....not sure why AMSOIL 75w90 would be bad though.

A tribologist on BITOG explained it really well between oils that are or are not good in the cold. One is like Pudding, the other like Pancake Batter. Though not dissimular in "feel", one pours and the other doesn't. If you stick a spoon in pudding, it doesn't fill in the whole when you remove the spoon.

Pablo on BITOG, one of the AMSOIL site sponsors, gave me some really good advice and helped steer me towards 75w110 instead of 75w90 despite my concerns about such cold viscosities and shift feel. I don't understand it, but as he put it "People look at viscosities as the whole story. But viscosities don't tell you how things are actually lubricated, how they interact with the lube between them, etc."....he basically said he expected 75w110 to work very well in this tranny. So far, I'd have to agree.

I still haven't put it in the rear diff. I'm wondering if any trans/drivetrain behavior will change.

Joe

P.s. Is copper alloy considered a "yellow metal"?

I have no comparison data at this time except against stock fluid. At some indeterminate time in the future, I'll switch to Extra-S most likely in the trans at least.

Joe

Small update - About 38 degrees fahrenheit this morning. Went into reverse on the first try (and continued to do that throughout the driving experience). No scratchiness or noises or grinds. My first shift into second gear was stiff....meaning it didn't go in right away. I applied steady pressure and after about .5-1 second, it slid in nicely.

If it maintains these characteristics to 20 degrees, I'll be happy. But a note....at 50 degrees, it wasn't feeling stiff. 12 degrees less, and I have stiffness. Hopefully it can handle another 15-20 degree drop and still be fine.

Joe

..........If it maintains these characteristics to 20 degrees, I'll be happy. But a note....at 50 degrees, it wasn't feeling stiff. 12 degrees less, and I have stiffness. Hopefully it can handle another 15-20 degree drop and still be fine.

 

Joe

How has the 75W-110 worked out for you so far this winter?

I'm still very pleased. It is stiff....meaning the gear lever requires more effort to move....when it's 20 degrees out. But there is no grind-i-ness, no scratiness, and all gears have a more positive "stop" when shifting....almost feels like I installed stiffer bushings, honestly. The shifting is quite nice, and I do think it's improving with time a modest amount.

My only complaint is that reverse is still locked out sometimes, moreso when cold. Honestly, this might be mechanical. But it upset my wife the other day when she was making a quick 3-point turn in the middle of the road and couldn't get into reverse quickly. I remind her to just go into 1st, then back to reverse. But she doesn't like that.

Can anyone with Extra-S comment on whether or not reverse remains locked out?

My biggest compliment to the AMSOIL 75w110 is that it makes the gears/trans feel much more like it's going to last a lifetime. It doesn't feel nearly as delicate, or likely to break or grind or wear against itself. I consider it $50 well spent.

Joe

My shifter in 15 degrees fahrenheit feels like it's moving through a very thick oil. It's not light, but it's not stuck either. And it's not ratchety.

Bear in mind that I haven't been down to 0 degrees here yet....I'd recommend this oil to people, but I'm one person with a good experience vs. like 50 good experiences for Subaru Extra-S (that being said, I don't know of anyone who have tried BOTH fluids)

Joe