Hard downshifts; Time for fluid change? TIPS PLEASE

Over the past week or so, I have noticed downshifting into 2nd becoming quite difficult. I read around on multiple forums that it is a common symptom of aging fluid, which typically happens around 25-30k miles on these cars. Well, mine is at 35k on what I assume is the original fluid, so that makes sense as a starting point. My questions are as follows:

 

1) I understand these transmissions are picky about fluid. With a few years of experience now, what is the recommended fluid? I live in Cleveland, so we do have pretty cold winters. I expect to see some differing answers, but hopefully can find a decent answer.

 

2) Is there anything tricky that I should know about changing the fluid? Is it as simple as drain and fill, as detailed here: http://www.subarulegacy.com/tech-articles/14-gearbox-and-diff-oil-change-manual-transmission.html ?

 

3) Am I correct that there are no filters that need to be changed during this?

 

Thank you everyone in advance for your unending wealth of knowledge!

1. I replaced my gear oil recentlyat 60k miles with this:https://www.amazon.com/gp/product/B005UGKJCS/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

While you're at it, dont forget to do the rear diff, so 5qts should be enough. Shifts are smooth as buttah

2. The front diff/trans is pretty straight forward drain and fill.

3. correct, there are no filters to change for the gear oil.

Motul is an excellent choice as well as redline shockproof, some people have used a combination of the two. There is also the subaru extra-s that is available, which is slightly cheaper than the other 2 but at a lower performance point too.

I recommend using Motul 300 for the transmission. I changed my fluid after the 1st winter. It will be much improved cold shifting in the winter. On cold days, my transmission shifter took a lot effort going into 2nd gear when I first drove out my driveway. I test drove a Legacy GT this summer and I noticed immediately the difference in the shift feel. I wasn't expecting the transmission shift feel to be on radar when I was driving LGT with what I assume was the factory fluids. (It has the same STi Short Throw Shifter my car has)

I've noticed with Motul that I'll have to double-clutch to downshift into 2nd if it's cold out, but only until the transmission fluid gets warmed up, and that's really the only thing I could call a negative. Seems like a fair trade, I no longer feel like I'm rowing a boat through molasses if it's really cold out (around 0F).

Another question: What additional parts do I need? I assume there are crush washers or gaskets involved, at a minimum.

The transmission has a crush washer. Differential and fill plugs have nothing.

Make sure you have T70 socket to open up the tranny.

And RTV for the diff plugs. As I recall, they're tapered threads, but a little bit of RTV to glue everything in isn't a bad plan.

Hey guys, I'm finally getting around to doing this. I drained and filled the transmission and have drained the rear diff. I read on several subaru forums that the rear diff should have 75w90NS, not just normal 75w90. Is this true, or can I still use the normal motul 300 75w90 back there as well? While I'm asking, is there any issue with running different fluids in each case? For example, extra S in the back and the motul up front? I only ask this because I ordered the wrong quantity and I can pick up extra S tomorrow, versus waiting for motul to ship to me. Thanks

No issues with using a different brand in the rear differential. I used valvoline synthetic in the rear diff, and AMSOil Severe gear in the transmission. No issues so far and I'm nearly 10k miles into the change.

Hey guys, I'm finally getting around to doing this. I drained and filled the transmission and have drained the rear diff. I read on several subaru forums that the rear diff should have 75w90NS, not just normal 75w90. Is this true, or can I still use the normal motul 300 75w90 back there as well? While I'm asking, is there any issue with running different fluids in each case? For example, extra S in the back and the motul up front? I only ask this because I ordered the wrong quantity and I can pick up extra S tomorrow, versus waiting for motul to ship to me. Thanks

 

I use Motul 300 in my rear differential, but their is no issue using a different properly weighted fluid in the transmission and the rear end.

The 5th-gen Legacy has an open rear diff, so you'd want the regular 75W90, not the limited-slip formula. Previous generations had a limited-slip rear diff, we have fancy computer magic that brakes individual wheels to mimic the behavior of a LSD.

The 5th-gen Legacy has an open rear diff, so you'd want the regular 75W90, not the limited-slip formula. Previous generations had a limited-slip rear diff, we have fancy computer magic that brakes individual wheels to mimic the behavior of a LSD.

 

And the symmetry helps as well, although I haven't heard of too many of us 5th genners having issues with rear wheel traction, lol.

Yeah, seems like the transmission generally starts making bad sounds before the rear wheels break loose.

Over the past week or so, I have noticed downshifting into 2nd becoming quite difficult. I read around on multiple forums that it is a common symptom of aging fluid, which typically happens around 25-30k miles on these cars. Well, mine is at 35k on what I assume is the original fluid, so that makes sense as a starting point. My questions are as follows:

 

1) I understand these transmissions are picky about fluid. With a few years of experience now, what is the recommended fluid? I live in Cleveland, so we do have pretty cold winters. I expect to see some differing answers, but hopefully can find a decent answer.

 

2) Is there anything tricky that I should know about changing the fluid? Is it as simple as drain and fill, as detailed here: http://www.subarulegacy.com/tech-articles/14-gearbox-and-diff-oil-change-manual-transmission.html ?

 

3) Am I correct that there are no filters that need to be changed during this?

 

Thank you everyone in advance for your unending wealth of knowledge!

 

No one has said this already but you may be due for a clutch. Hard shifting or reluctance to go into gear might be a sign that the clutch surface is worn or the pressure plate isn't functioning the way it should.

 

Another question: What additional parts do I need? I assume there are crush washers or gaskets involved, at a minimum.

 

https://www.amazon.com/dp/B00IGZQA3W/ref=wl_it_dp_o_pC_S_ttl?_encoding=UTF8&colid=VR63I4OMTAL2&coliid=I3PX81ORNML4VR

 

^ You need that. Also I've gone through four different trans fills in 85K. The notchy feeling isn't going to go away.

Have you tried Scotty's Cocktail? Works a treat in the 5MT your trans is based on.

Hey guys, so I've done the change with Motul 300 and driven on it for a few days. It still seems pretty hard to get into 2nd sometimes. It may be marginally better, but that may also be in my head because I WANT it to be better.

 

Upon draining the old fluid, I did notice that it was pretty dark. Am I right in assuming that it is due to a ton of small steel particles? Am I also right in assuming that this is a very bad thing?

 

Lastly, is there anything else that could cause this, aside from the big stuff? Would low or old clutch fluid potentially cause something like this?

 

Again, all input is welcome.

 

Thanks!

A worn clutch could cause shifting issues as well, but check the fluid after a few hundred miles and see what it looks like. You may need to change it again to get the mucky old fluid out.

 

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Would a worn clutch cause difficulty getting into gear, though? I thought that, typically, a worn clutch will just not grab properly when released.

 

And I hope not, that oil isn't cheap! I will check the fluid level out again soon.

Are you rev matching when downshifting? It's harder on the sychros if you don't rev match. It can also be hard if you're speed is on the high end of the gear.

 

Have you tried double clutching to see if it's a possible synchro issue? May not be a completely shot synchro just beat up a little.

Sorry to bring this thread back to life, but I had another question about a potential problem/solution.

 

Is it possible that the clutch is not completely disengaging when I press it in? Sometimes it feels like there is still contact. I would guess that, if this is the case, air in the system, bad fluid, or some other issue would cause incomplete disengagement, resulting in a small amount of friction and possible difficulty shifting/improper meshing. Is this correct? Or could it be a matter of an adjustment somewhere? Or am I way off here? As always, all input is appreciated.

Did you do the clutch damper delete? If the damper is beginning to fail like it did for SurlyOldManMN, then your wingtips will get ruined when it does completely fail. If the hydraulics are not completely releasing the pressure plate from clutch disc you could have hard shifting. Many things can cause that but most of them are unlikely on your 5th Gen.

 

Have you flushed and bled your clutch hydraulic fluid to get all fresh fluid in there? You can use any DOT4 brake fluid, I used Castrol.

This is interesting..I get a grinding noise on turns (only after fairly extended driving). Three different Subie Dealerships has said it is NOT CV related, and when they test drive it, the car has already cooled and it is not test driven extensively. Never had my Gear Oil change (70K) running Stage II, Exedy Stage II clutch also. Well overdue huh? How many quarts if Motul required?

Get that gear oil changed ASAP!!!!! Especially since running stage2. Rear diff takes 1 quart, and IIRC, the tranny/front diff takes 4 quarts.