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My tranny fluid is on the low mark of the dip stick. I'd like to top it off. The manual says not to mix oil from other manufacturers. :-?
 

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When I had my tranny and rear end oil changed in my 02 wrx the dealer said it was some kind of synthetic from Subaru, so I wouldn't assume anything untill you find out for sure.

Jim
 

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Well I whipped out my dipstick last night :oops:

And I'd swear it smells just like regular old 90w gear oil............
 

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StaticX Grounding Kits

what do you guys thinking about swapping to red line synthetics? I kinda wanted to do the redline synthetic mtl tranny oil and differential oil...

Robert~
 

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There's a gear oil thread on NASTIOC that says Subaru uses a non-synthetic Valvoline:

http://forums.nasioc.com/forums/showthread.php?s=&threadid=416514

The thread is long and not STi-specific, but it's worth checking out. The bottom line is that WRXs are very picky about their gear oil. I'm not switching from the OEM lube until I hear about long-term STi owners who've happily switched. The 6MT might be more tolerant than the 5MT, but I had enough 5MT problems that I'm not going to take any chances.
 

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I just got back from service center now and put in synthetic 75-90 tranny oil and rear diff oil :) ahh yeah how much nice the gears shift, no morning sludge anymore :)
 

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For the last month I was reading all I could find on gear oil because I was going to change my trans and diff oils at 10k. After reading so much conflicting info I came to the conclusions that pretty much all synthetic gear oils, in one way or another, cause problems down the road in the trans. They feel great at first but after a while one person has trouble getting into certain gears, another person grinds certain gears. I don't know, but for now I think I will just stick with the stock fluid and if I don't hear about a good oil by spring I might just stick with a regular, non-synthetic gear oil.

BTW, I heard a couple people say Subaru uses Valvoline gear oil. Don't quote me on that though.
 

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MKIVSupra said:
...BTW, I heard a couple people say Subaru uses Valvoline gear oil. Don't quote me on that though...
Yeah maybe you subconsciously saw slowride's post 2 above yours and clicked on the NASIOC link. :wink:
 

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We just changed mine this weekend, and called the dealer to verify what they used. They told us 80/90.
I ended up going with Mobil 1 Synthetic 75/90 and I'm happy with the results. Going into gears are a slight bit smoother.
 

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SnowbordrWRX said:
MKIVSupra said:
...BTW, I heard a couple people say Subaru uses Valvoline gear oil. Don't quote me on that though...
Yeah maybe you subconsciously saw slowride's post 2 above yours and clicked on the NASIOC link. :wink:
No I did not go to the link but I bet I already read the thread he linked to.
 

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STiGirl said:
We just changed mine this weekend, and called the dealer to verify what they used. They told us 80/90.
I ended up going with Mobil 1 Synthetic 75/90 and I'm happy with the results. Going into gears are a slight bit smoother.
Yeah right now it shifts nice but wait a few thousand miles and see how it is. Like I said most people love synth oil in the trans initially but then after a few thousand miles they are having problems.

Eveyone that switched to synth will have to keep us posted on how it is after a few k miles.
 

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I changed oil in my 1998 RS to full synthetic after 600 miles had the car for 70K miles no issues. I know its not a WRX or a STi but the concept is still the same its a gear box.
 

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From what I read the problems have to do with the synchroes. The bearings love a good slippery oil while the synchroes like some friction to get into gear. If you drive normal and take your time shifting you can get by with a good synthetic. If you shift hard and fast, too slippery of an oil will give you problems getting into gear down the road.

At 11k miles now my trans shifts beautifully. I am almost scared to even mess with it. That is why I am really having second thoughts and decided to wait till spring before I change the fluid in the trans and diffs. I read a lot of posts on different forums about people changing to a synthetic and saying how great it is now only to come back a few k miles later and say how it grinds or is hard to get into certain gears.
 

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i think if you look at any and all major racing classes and teams everyone is using synthetic oils, be it gear or engine. the only downfall to running synthetics is cost. in every other way they beat out conventionals. be it in reduced friction or in resistance to heat. it is possible that someone used the wrong synthetic in thier gearbox. most companies make a RACING formula that is not recommended for use on the street. its possible that someone used a racing variation and that could have been the issue.
 

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MKIVSupra said:
From what I read the problems have to do with the synchroes. The bearings love a good slippery oil while the synchroes like some friction to get into gear. If you drive normal and take your time shifting you can get by with a good synthetic. If you shift hard and fast, too slippery of an oil will give you problems getting into gear down the road.

At 11k miles now my trans shifts beautifully. I am almost scared to even mess with it. That is why I am really having second thoughts and decided to wait till spring before I change the fluid in the trans and diffs. I read a lot of posts on different forums about people changing to a synthetic and saying how great it is now only to come back a few k miles later and say how it grinds or is hard to get into certain gears.
Coming from the Audi 6-speed (mated with the 2.7T, not the new one for the 4.2) I have to say the gear change in this car is damn nice. My Audi's tranny was so notchy it wasn't even funny. I wouldn't touch a thing, because in my mind it can't get much better.

-st
 

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crashsti said:
i think if you look at any and all major racing classes and teams everyone is using synthetic oils, be it gear or engine. the only downfall to running synthetics is cost. in every other way they beat out conventionals. be it in reduced friction or in resistance to heat. it is possible that someone used the wrong synthetic in thier gearbox. most companies make a RACING formula that is not recommended for use on the street. its possible that someone used a racing variation and that could have been the issue.
Hey I am not saying that synthetic is bad to use I am just stating what I have read about people's experinces. I have yet to read one post from a WRX owner that with long term use they had no problems with their trans after switching to synthetic. None of them used any special racing formulas just your basic redlines, royal purples, mobil 1s, etc. There are a lot of things racing teams do and use but they also rebuild things on a regular basis. I am all for synthetic fluids and religiously use synthetic motor oil. I really want to switch to synthetic gear oil but based on what I have read so far I would rather just use regular gear oil and change it more often.
 

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MKIVSupra, I find the generalization that synthetic oil can be bad for all/most gearboxes to be sketchy. It's hard to get solid infor whent here are so many anecdotes out there, But FWIW, I ran synthetic for 70k hard miles in my TT Z tranny and diff, and 87k hard miles in my M3 tranny and diff, and they both felt great. I have never heard anyone complain about synthetic oils, ever. My guess is that it's more an a tranny issue than an oil issue. But who knows :(
 

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I didn't mean to sound like I am saying synthetic oil is bad in all transmissions, I am mainly talking about WRX 5spds. I ran synthetic oil and gear oil in all my other cars except my Supra trans due to the Getrag trans being very picky on fluid, and have not had any problems. Actually maybe the oil Toyota uses in the Supra trans is some sort of synthetic oil, all I know is it is Supra specific, not cheap, and people that tried other oils had problems. Anyway I am sure it is somehow trans related. I WANT TO use synthetic gear oil but if it is going to give me problems down the road I would rather use regular gear oil and be able to shift ok. Of course what I have read is related to the WRX 5spd maybe our 6spds are different. I don't know. I will wait and see what happens with the people that have switched out the STi gear oil to synthetic before I do it.
 
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