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i have a 2001 impreza with almost 30k miles. i am goingto change the gear oil at 30k and was wondering what kind to use. i dont want to shorten the life of anything as i do a lot of driving. i do a little under 1k miles a week. the driving i do is mostly in town on roads that are 40mph. i do some highway and some slow roads. i do a moderate amount of shifting in my drive. any help would be great. thanks

also, what else should i change at 30k
i use mobil 1 synthetic every 3k miles, my manual says to change it every 7500 miles, am i going overboard? it seems like it needs one every 3k, subarus are oil hogs has been my experience
 

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while i'm not a scooby expert... Redline fluids are one of those products I fully stand behind. If you know anything about VW's, you'd know that since 1985 the 2nd gear in 5speeds always developes a grind. Redline MTL takes it away (if it's not too far gone). I switched to MTL at 110K, where I'd grind almost every time, and now even at 169K it's a rarity to crunch 2nd.
 

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I've been using Motul Gear 300 for like 25k miles now (since about 15k) and it works great. (Plus, Motul is what the Subaru WRC cars use.)

DON'T use the Mobil 1 Gear Oil that you find at auto parts store or automotive departments. It works great in the rear diff, but it's too slick for the tranny.

Peaty has posted several times that Redline Shockproof Lightweight works well.

Supposedly the "official" Subaru gear oil that the dealers use is synthetic, too (from what I've read).
 

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ampsarus said:
The Mobil 1 GL5 gear oil is like 85w-90...what do you mean "too slick"? :confused:

Thanks
Well the only ones I've seen were 75W90 (the same weight called for by the Subaru manual) BUT they have friction modifiers (like the non-NS version of the Redline gear oil does). I am running the Mobil1 in my rear diff right now, but was advised against running it in the tranny (by several people including RalliSpec). According to RalliSpec, Mobil1 DOES have a gear oil that will work but isn't sold in smaller than 5-gallon quantities... :lol:

Anyway, so I went and installed the Motual Gear 300 (based on reviews I'd read) and have no complaints about it at all. (I've since started converting my other fluids to Motul as well...motor oil, brakes, etc...it does cost a little more than Mobil1 though (I was running Mobil1 motor oil also before)).
 

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Friction Modifiers are used to make some LSDs work better but the synchros in many manual trannies don't tend to like them as they need at least some resistance to work. (Subaru's VLSD is sealed anyway, so the friction modifiers wouldn't affect it anyway, though they are still better for the gears themselves.)

So simply put, gears like it as slick as possible, synchros not so much... :lol:
 

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So what's the general consensus on which oil to use in the tranny and which to use in the diff? The posts above are slightly confusing since folks are talking about both in the same thread, and different oils as well (hell, maybe I'm just dense).

I've got MTL in my 94 rx-7's tranny and mt-90 in the diff, but I dunno if that's the same combo that's recognized as the "standard".

I'm open to suggestion, so I guess gimme what you got :)
 
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Warp3 said:
Friction Modifiers are used to make some LSDs work better but the synchros in many manual trannies don't tend to like them as they need at least some resistance to work. (Subaru's VLSD is sealed anyway, so the friction modifiers wouldn't affect it anyway, though they are still better for the gears themselves.)

So simply put, gears like it as slick as possible, synchros not so much... :lol:
I see, thanks for the info! :nuetron:
 

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Discussion Starter #10
so...:confused:
what gear oil should i use? should i use one with friction modifiers since the LSD is sealed? can i have the brand and weight of the oil for both the diff. and the tranny, please.
thanks, ryan
 
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Flashing red light going off in my head

The Subaru manual specifies API classification GL-5 oil, and Redline's website says the MTL amd MT-90 are GL-4.

EDIT: After a little more checking around it looks like Redline 75w-90NS is the right stuff for the trans.

I'm going to call them and see if they have any Subaru-specific advice. :)
 

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To recap:

The Subaru 5MT is a bit picky about gear oils (thus the above posts). I've personally had good luck with Motul Gear 300 and read about good luck with Redline Shockproof Lightweight and Redline 75W90NS.

The Subaru rear diff is not nearly as picky and (like all gears) simply likes it slick. So you can either use the same thing as you use in your tranny or something else. (Right now I have Mobil1 75W90 from AutoZone in my rear diff and it's fine (though the tranny supposedly doesn't like it). I plan to change it to Motul as well but that's more for consistency with the fact that I'm running Motul everywhere else.)
 

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warp3, how much of the stuff do you use 3 qts, 1 qts. how much in the front and how much in the rear, i do not want to drop it and not have enough to refill. i looked at the mobil 1, and where do you find the motul gear 300?
And how do you get the oil out of the manual trans in the front to replace that, i know hwere and how to get it out of the back.
 

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I don't remember what the capacity is, but the info is in the owner's manual.

To drain, there is a drain plug located on the bottom of the transmission. To fill, remove the dipstick from the top of the tranny (behind the engine, below the throttle body) and fill it through the dipstick hole (get a funnel with a long tube on the end...lol).
 

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I bought my latest Motul products from Prestige Subaru in Asheville, NC (http://www.prestige-motorsports.com/). Ask for Bill in the parts department (goes by Scooby South and Prestige Subaru on NASIOC).

Also many motorcycle shops sell Motul lubricants.
 
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Warp3:::: Is this how you do it?

(I think the rear diff capacity is 1.6 quarts, but nevermind that) Just remove both plugs on the diff cover to drain. Put the bottom plug back in. With the car level, pump in oil until the stuff runs out the top plug hole. When it stops running out, that is the correct level.
 

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Warp3 said:
I don't remember what the capacity is, but the info is in the owner's manual.

To drain, there is a drain plug located on the bottom of the transmission. To fill, remove the dipstick from the top of the tranny (behind the engine, below the throttle body) and fill it through the dipstick hole (get a funnel with a long tube on the end...lol).
You can also get a really inexpensive pump from your local autoparts store that allows you to just pump the fluid out of the bottle and into your tranny/diff. It made life easier when doing the tranny on my rx-7, and if it weren't for that pump, I doubt I could have gotten it filled.
 

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kramp said:
You can also get a really inexpensive pump from your local autoparts store that allows you to just pump the fluid out of the bottle and into your tranny/diff. It made life easier when doing the tranny on my rx-7, and if it weren't for that pump, I doubt I could have gotten it filled.
or you can get a ketchup pump from Lion's Choice, but that's another story :)

just fill it until it is about ready to spill out the upper hole, then stop and cap it off and you're done.
 

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Royal Purple...85-90 GL5...same bottle in the dif. and gear box....

I'm running it and my car goes into reverse now believe it or not, shifting is less "sticky", and the car pulls a little harder.

Here’s why.

Oil has to do two things.. lubricate and flow. Synthetic oils have much more viscous catalysts than conventional oils helping the oil flow faster. The faster oil flows the less parasitic loss you see and the more power you put to the ground. It’s that simple.
 
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