Changed Fluid in Diffs/MT 2014 WRX

[Pablo]

So today I drained the rear diff. 75W-90 GL-5 recommended.

Put Amsoil 75W-110 in. Uneventful, but wow there was a lot of iron on the stock magnet. I used a 13mm square plug tool. Wasn't even as tight as predicted from Subie threads. I re-used the stock magnet drain plug for the fill plug and installed a Dimple drain plug which is 17mm hex. Fluid that came out seemed like a 90 wt, not so sheared. Did not retain a sample.

Then I drained the transmission - it was a different fluid than the rear. Very thin - apparent viscosity doesn't mean a whole lot but it gushed out like water and I must add the shifting was getting progressively worse (notchy and rough 3800 miles!) and I could hear the transmission, so I would say the factory fill sheared severely. I filled with 3.8 qts of Amsoil 75W-110. Used a funnel with a plastic flex hose. Worked great. Did not retain a sample. Some fuzz on stock magnet - T-70 TORX. Installed a Dimple drain plug.

I had the car on ramps on all four wheels, level. Race ramps and Magnum Ramps.

Test drove, the transmission shifted like butter and is quiet again. I was frankly astonished. SWEET!!

I LOVE MY WRX!!

 

[147_Grain]

Pablo:

That preliminary / early-on maintenance will pay dividends in the long-run. Most people don't realize the validity of metal particles in the fluids as the internal parts mate together.

I also performed similar maintenance on the 2013 Subaru Outback to get the contaminating metal flakes out of the factory fill break-in oil.

At 5,000 miles, the front and rear differentials were refilled with Amsoil Severe Gear 75W-90 and the 5-speed Automatic Transmission was drained and filled several times with synthetic ATF.

Made a noticeable difference on smoothness and a slight increase in MPG.

 

[Pablo]

Did your diffs have the 13mm square bung holes?

 

[147_Grain]

I believe so.

I know the Subaru Service Manager well and he only charged me $28.00 for the labor portion to change both diffs and transmission fluid. I provided the fluids.

 

[yvon_la]

Subaru use a special kind of gl 5 oil ,almost none are like the Subaru recommended .it is a gl-5 that is specced with gl-4 limit!(good on brass etc,very rare to see a gl-5 behave like this!

 

[thescreensavers]

I didn't have to buy a socket for the rear diff you can just use your 1/2" breaker bar or socketwrench with no socket on it. Its the same size as your 13mm

I also noticed better shifting when I changed out the trans fluid though I used Subaru extra S

 

[Pablo]

Originally Posted By: thescreensavers
I didn't have to buy a socket for the rear diff you can just use your 1/2" breaker bar or socketwrench with no socket on it. Its the same size as your 13mm

I also noticed better shifting when I changed out the trans fluid though I used Subaru extra S



Yeah I've seen 13mm plugs where people used the 12.6mm (.499" or 1/2") breaker bar. No thanks. It's not the same and the plug is 13.1mm.


Originally Posted By: yvon_la
Subaru use a special kind of gl 5 oil ,almost none are like the Subaru recommended .it is a gl-5 that is specced with gl-4 limit!(good on brass etc,very rare to see a gl-5 behave like this!


I could have used GL-4 MTG, but what you say is not what Subaru recommends. I believe a GL-4 may shift marginally better (certainly not proven), but I know a GL-5 will protect the gears better. Especially a 20 cSt@100°C GL-5. I don't think I realized at first how HOT this box gets. When I was doing the way bars the thing was scorching hot. I changed it cold and the fluid came out like alcohol. My guess is the Amsoil will shear as well, so it should end up in the 16 range and be perfect.

 

[HTSS_TR]

If Amsoil 75W-110 shears down to lower than 15 cSt@100°C after 20-30k miles then you can fill a complaint to Amsoil.

 

[i812]

Image provided by "Altabrigs" from subaruoutback dot org

My 3.6 is a 13mm hex plug, compared to the 2.5L square plug.

 

[Kuato]

Early changes adds up to better longevity IMO. Looks like easy jobs, too.

Drive = Love. I've been considering a Subaru for some time; seems like everyone that has one, loves it. And the WRX is a great performing vehicle.

 

[yvon_la]

mm!from what I saw on Subaru forum,subaru gl-5 is like a synchromesh type oil ,yes it is a gl-5 but not hard on brass or bronze synchromesh (whatever they use in gl-4 transmission,cant recall if its br5ass or bronze)

http://www.subaruforester.org/vbulletin/

 

[147_Grain]

Originally Posted By: Kuato
Early changes adds up to better longevity IMO. Looks like easy jobs, too.


+1

 

[Pablo]

Originally Posted By: yvon_la
mm!from what I saw on Subaru forum,subaru gl-5 is like a synchromesh type oil ,yes it is a gl-5 but not hard on brass or bronze synchromesh (whatever they use in gl-4 transmission,cant recall if its br5ass or bronze)

http://www.subaruforester.org/vbulletin/


The old fashion/notion or assumption that all GL-5 fluids are hard on brass/bronze/yellow metals/copper alloys is incorrect.

 

[artificialist]

Heavy gear oil in the rear diff doesn't surprise me. Many Japanese car companies still like to use SAE90 in differentials and transfer cases.

That is what my car came with, and what the dealer sells. I'm glad that I replaced the stuff.

 

[SubLGT]

Originally Posted By: Pablo
………...and installed a Dimple drain plug………...


Why?

 

[Pablo]

Originally Posted By: SubLGT
Originally Posted By: Pablo
………...and installed a Dimple drain plug………...


Why?


Because the magnets are stronger at high temps and all three take 17mm wrenches and I can reuse the OEM magnet drain plug for the fill plug on the differential.

Why do you ask?

 

[SubLGT]

Just curious, that's all.

 

[BHopkins]

Originally Posted By: Pablo
Originally Posted By: SubLGT
Originally Posted By: Pablo
………...and installed a Dimple drain plug………...


Why?


Because the magnets are stronger at high temps and all three take 17mm wrenches and I can reuse the OEM magnet drain plug for the fill plug on the differential.

Why do you ask?


Is there evidence that the factory magnetic drain plugs aren't doing the job well enough? Are there issues with damage to Subaru differentials from metal particles?

I'm just trying to decide if this is something that I need to add to my Outback, when I do my 30k service. Or is it really just a preference?

 

[Pablo]

Originally Posted By: BHopkins
Originally Posted By: Pablo
Originally Posted By: SubLGT
Originally Posted By: Pablo
………...and installed a Dimple drain plug………...


Why?


Because the magnets are stronger at high temps and all three take 17mm wrenches and I can reuse the OEM magnet drain plug for the fill plug on the differential.

Why do you ask?


Is there evidence that the factory magnetic drain plugs aren't doing the job well enough? Are there issues with damage to Subaru differentials from metal particles?

I'm just trying to decide if this is something that I need to add to my Outback, when I do my 30k service. Or is it really just a preference?


No evidence at all. My advice is to clean the factory plugs off really well and reuse them. The Dimple plugs are really, really nice - but there is absolutely no need to use them. I was just posting what I did, not saying it's necessary.

I would say there could be damage if one doesn't change the factory fluid out way sooner than recommended. There certainly was a ton of iron on that factory diff plug. It will be interesting to see how much junk will be on both the drain and the fill (stock) magnet next time. It only holds a quart!

As for the transmission. The factory fluid is JUNK.

 

[sprintman]

No Amsoil 75W110 here unfortunately as I'd use it in the Forrester I just got and the Falcon LSD