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Center differential fluid change?

37K views 16 replies 7 participants last post by  Turbospeed  
#1 ·
It just occurred to me that, while I have changed the fluid in the rear diff and front diff/transmission, I never gave the center diff any attention. Is this a system that needs fluid changed periodically?
 
#9 ·
Friction modifiers are usually for clutch/plated LSD. We don't have any of those ;-(

I do recall that diffs can benefit from extreme pressure additives (usually the stuff that makes it smell sulphury) but those additives are not always the best for synchronizers in a transmission.

I am looking forward to changing out for the extra-s soon.
 
#8 ·
i used extra-s in the tranny and rear diff. as said previously,the tranny and front diff are all the same drain and fill tube. the extra-s shifts soo nice even in the coldest winter days.
 
#10 ·
I jumped the gun a bit and did the switch at only just shy of 30k miles. Probably could have saved some money and waited on the rear diff since that's not something I'll notice a difference with, but doing the trans/front was definitely worth it.
 
#12 ·
Can anyone tell me what tool I will need for the rear diff AS WELL as the front transmission bolt? My 05 STI buddy told me he had to buy a T70? or T60? I forget..
 
#13 ·
Looks like T-70 Torx for the front diff/transmission drain. Rear diff is a square female that either a 1/2" or 3/8" drive wrench or breaker bar will fit (I don't remember which size, but both are common toolbox items). When doing the rear, remove the top/fill plug FIRST. Just in case - if you can't get that out and need help, but you've already drained the rear diff, the car's pretty much stuck where it's at unless you tow :)
 
#14 ·
its a t70 bit. i bought one off ebay for like 8 bucks. the rear diff is just a 1/2 square drive extension opening.
 
#15 ·
^^ and ^

Wow, it took me an hour with a 20 minute break because of sudden rain for the whole thing. Tranny fluid and rear diff. Thanks so much for the fast responses. I recommend doing this for anyone reaching 30-36k miles ! I can definitely feel the smoothness in the gas pedal and clutch. Especially when accelerating and shifting up..

Next, I think I'm going to do a kartboy ss and shifter bushings.
 
#16 ·
^^ and ^

Wow, it took me an hour with a 20 minute break because of sudden rain for the whole thing. Tranny fluid and rear diff. Thanks so much for the fast responses. I recommend doing this for anyone reaching 30-36k miles ! I can definitely feel the smoothness in the gas pedal and clutch. Especially when accelerating and shifting up..

Next, I think I'm going to do a kartboy ss and shifter bushings.
the fluid change really helps with the smoothness of shifting. i can downshift into first coming to a stop now. before it was almost impossible to get in gear.