Hope this isnt a dumb question but...when should you change the tranny fluid in the wrx 5spd? what brands of fluid do you reccomend and how hard is this to do? my car currently has 35,xxx mi on it and was starting to wonder when i am supposed to do this. How about the rear diff as well, when for that and what fluids? dont worry im not a total moron, i change my oil every 3k so i dont have questions about that one. any help would be greatly appreciated. thanks

tim

 

no input?

 

i'm not exactly sure but doesn't the maintenance manual say every 30k you change your tranny oil? i did mine at 10k to synthetic, then again at 30k. i'm also going to do it at 60k. rear dif you do it at the same time. i'm running amsoil.

-brento

 

imo the transfluid should be changed the minute u drive the car off the lot. the stock gearbox feels like a stick in a bucket of rocks, put some syncromesh in there and you will notice a big difference

 

I use Redline mt-90 for Trans and redline 75w90 for the rear diff and nothing but good things to say about it.

 

I changed out my trans fluid to Specialty Formulations MTL-R synthetic, big improvement. I can shift into first from 25 mph, never had grinding since I used this fluid.

 

look up on the 30k service, there might be some other things you may also want to change if you havent done so already...

 

guess its time to change radiator fluids too...prolly change to new hoses at that time too

 

Any STis running Uncle Scotty's cocktail here in the islands? I'm on the fence on this one. Could any of you STi owners out there state what you are running?

 

Why use a cocktail? The problems with cocktails is that 1 component of one fluid could counter act another in another fluid. There are reasons why certain manufacture produce their own gear oils and additives...etc.

For me in my transmission I'm currently running Amsoil Severe Gear 75W-90 with NO grinding...etc. I had some trouble after a long time getting into 4th gear when downshifting and while even rev matching from 5th. It just wouldn't go in and not even shoving it in would work. I had to actually get on the brake to get the synchros to open up. After using this I haven't experienced the problem.

This is not a recommendation for anyone just what I use. Other people complain about Amsoil being to slick and causing grinding but I've never had any trouble with either my automatic or manual 6 speed transmission.

For the sake of this thread, the OP should look at the maintenance interval or do a search on i-club in general. This has been covered many times.

Everyday a new i-clubber is born and all seem to ask the same or similar questions. There are other forum areas than HIIC that have valuable information in them. Regarding this question you might find more exact details on types of oils used in the maintenance section of i-club

Jon

 

uncle scotty made the mix for the more finicky 5spd transmission, where people have issues with grinding. it works for alot of people. id say just stick to a regular fluid if you have an sti, and if you are that desperate with a wrx try the cocktail if you are willing to accept the risks. also, syncromesh is rated as a gl-4 fluid. i believe subaru requires a gl-5 fluid. if you are having problems, a fluid isnt supposed to fix a broken transmission...

i think made a mistake trying out the cocktail, first, i didnt need it, second, the components where kinda hard to track down, third jon's explanation of fluids counter acting with each other as there was no professional testing, researching, engineering (whatever you wanna call it) put into it. i have no complaints about how the fluid is currently performing, the car runs fine with it. i was just curious about the mix as you may be now when put i it in.

 

I read the entire thread on Uncle Scotty's cocktail on Nabisco and still could not make a decision. So the Sti requires a GL5 type? I went to Vakamon today and they had only GL4 transmission fluid (Redline). I asked Ryan to bring in whatever my STi needed. BTW no problems with my tranny, just hit 30K and it seemed like now was the time to do it.

 

Changing trans fluid is almost like changing engine oil.. What to buy?

Although.. you'll either feel an immediate difference or not.

Technically, the subaru transmission (didn't get to do much research on the 6-Speed) has a hypoid final drive which requires a GL-5 rated lubricant.

A GL-5 lube needs "Extreme Pressure" additives, for differentials and such that generally have a very high load / sliding action. Subaru's front final drive gear requires this. However, synchros work best without these E.P additives (relies on friction to work) GL-4 rated additives do not use E.P additives. What has been said about synchros is that E.P additives tend to reduce life of synchros by about half, and contain a chemical that is corrosive to brass; what synchros are made of. Supposedly.

But one thing is for sure. I have a headache, just as you probably do, and it comes down to a compromise between front final drive gear wear and synchro life/performance.

Supposedly the factory fill at subaru dealerships for the transmission is Valvoline 75W-90 non-syn.

 

Same here, just hit 30K, time for maintenance

 

hey d...go to the redline store, they have the gl5 transmission oil and gear oil 75W-90.