Which diff? Or was this the tranny?
post your latest differential fluid change
- Thread starter electrolover
- Start date
1992 Mercedes Benz 300D 2.5 turbo, 152,020 miles
Out: Castrol Axle 80W-90
In: same
Gold Plug GP04 M24x1.5 taper magnetic drain plug
Out: Castrol Axle 80W-90
In: same
Gold Plug GP04 M24x1.5 taper magnetic drain plug
4WD
$50 site donor 2025
2020 Wrangler Rubicon - annual rear axle oil change. 31k.
This M220 shed lots of metal first couple years similar to what CarbonSteel experienced - plan to run this oil 2 years …
Out: Delvac 1 75W90
In: Amsoil SG 80W90
This M220 shed lots of metal first couple years similar to what CarbonSteel experienced - plan to run this oil 2 years …
Out: Delvac 1 75W90
In: Amsoil SG 80W90
2018 Lexus GX460 @ 68k miles.
Out: Mobil 1 75w90 in diffs & Toyota 75w in transfer case
In: Mobil 1 Delvac 75w90 in diffs & Liqui Moly 75w in transfer case
I was surprised by how dirty the front diff oil looked with 33k miles on it. Transfer case fluid looked practically new.
Out: Mobil 1 75w90 in diffs & Toyota 75w in transfer case
In: Mobil 1 Delvac 75w90 in diffs & Liqui Moly 75w in transfer case
I was surprised by how dirty the front diff oil looked with 33k miles on it. Transfer case fluid looked practically new.
1993 Volvo 240 wagon, 212,120 miles
Out: 80W90/85W140 mix > 85W110
In: same
Out: 80W90/85W140 mix > 85W110
In: same
2019 Lexus GX460
55,1xx miles on vehicle
Rear diff drain and fill (OEM calls for 75w85 gl5)
Out - Motul Gear 300, 75w90 (gl5), 39000 miles approx on oil.
In - Valvoline Full Syn Flex Fill - 2qts 75w90 (gl5) and 1 qt Valvoline Full Syn 75w140 (gl5) (transferred to empty flex fill bag to fill case)
Went with flex fill bags b/c my motiv power fill is in storage out of state. While squeeze bags were not difficult. I think the motiv power fill worked more quickly and easier.
Next will be front diff (1.5 qts 75w90 Valvoline) and transfer case (75w Redline mt-lv).
Much less debris on magnetic drain plug compared to first drain at 15,800 miles vs this 39k mile run.
Motul drained oil dark, but less silver/gray streaks and debris compared to initial drain of oem fluid.
55,1xx miles on vehicle
Rear diff drain and fill (OEM calls for 75w85 gl5)
Out - Motul Gear 300, 75w90 (gl5), 39000 miles approx on oil.
In - Valvoline Full Syn Flex Fill - 2qts 75w90 (gl5) and 1 qt Valvoline Full Syn 75w140 (gl5) (transferred to empty flex fill bag to fill case)
Went with flex fill bags b/c my motiv power fill is in storage out of state. While squeeze bags were not difficult. I think the motiv power fill worked more quickly and easier.
Next will be front diff (1.5 qts 75w90 Valvoline) and transfer case (75w Redline mt-lv).
Much less debris on magnetic drain plug compared to first drain at 15,800 miles vs this 39k mile run.
Motul drained oil dark, but less silver/gray streaks and debris compared to initial drain of oem fluid.
Last edited:
2016 Ford F-250 Rear Differential 188726 miles on the truck.
Out: I assume factory fill, had a tan tint indicative of water contamination but everything else looked good.
In: MFA 75w140
Also repainted the diff color with some Machine Gray paint I had laying around. Should hopefully stop the little bit of surface rust it had.
Out: I assume factory fill, had a tan tint indicative of water contamination but everything else looked good.
In: MFA 75w140
Also repainted the diff color with some Machine Gray paint I had laying around. Should hopefully stop the little bit of surface rust it had.
2019 Lexus GX 460
Approximately 55,400 miles
Front Differential (oem is 75w85 gl5)
Out: Motul 300 75w90, last changed at 15,800 miles.
In: Valvoline Full Syn Flex Fill bags 75w90 gl5
Did the front diff today. Second change.
Good thing I had Kaon replacement diff plugs with 24mm heads. Had a rough time getting the oem 10mm hex plugs off. Even though I hand snugged with ratchet last time. 24mm socket Kaon plugs should be easier to remove next time.
Fluid was gray, but not as bad as rear diff or initial front diff oem change. Insignificant amount of gunk on drain plug magnet.
Checked rear diff level too since I had car up and level (changed in post above at 55k).
Probably will send samples of used diff, transfer case and last oil change to lab for uoas.
I love the smell of gear oil in the morning, it smells like…,VICTORY.
Approximately 55,400 miles
Front Differential (oem is 75w85 gl5)
Out: Motul 300 75w90, last changed at 15,800 miles.
In: Valvoline Full Syn Flex Fill bags 75w90 gl5
Did the front diff today. Second change.
Good thing I had Kaon replacement diff plugs with 24mm heads. Had a rough time getting the oem 10mm hex plugs off. Even though I hand snugged with ratchet last time. 24mm socket Kaon plugs should be easier to remove next time.
Fluid was gray, but not as bad as rear diff or initial front diff oem change. Insignificant amount of gunk on drain plug magnet.
Checked rear diff level too since I had car up and level (changed in post above at 55k).
Probably will send samples of used diff, transfer case and last oil change to lab for uoas.
I love the smell of gear oil in the morning, it smells like…,VICTORY.
Last edited:
2019 Lexus GX460
55,400 miles
Transfer case fluid change
Out: OEM Toyota 75w golden fluid w/unicorn tears
In: Redline mt-lv 70/75w approved by my
(shiba inu).
Easy peasy. Used empty valvoline flex fill bags to fill up with the redline mt lv. Should be good for another 60k miles. No particles in the drain pan after dumping into my used oil container.
Next is brakes, brake fluid, coolant (radiator only drain/fill), transmission drain/fill, and power steering fluid for 60k maintenance.
If only it were a bit cooler here in TX…time to re-hydrate.
55,400 miles
Transfer case fluid change
Out: OEM Toyota 75w golden fluid w/unicorn tears
In: Redline mt-lv 70/75w approved by my
(shiba inu). Easy peasy. Used empty valvoline flex fill bags to fill up with the redline mt lv. Should be good for another 60k miles. No particles in the drain pan after dumping into my used oil container.
Next is brakes, brake fluid, coolant (radiator only drain/fill), transmission drain/fill, and power steering fluid for 60k maintenance.
If only it were a bit cooler here in TX…time to re-hydrate.
Last edited:
Friend's 2010 Nissan Frontier XE 2.4L 2WD
Mileage: 92,640
Out: last fill done at 15,000 miles before friend bought the truck. Old fluid looked decent, brownish color with no metal bits.
In: Napa Premium GL-5 gear oil (2010 manual does not spec synthetic fluid)
Mileage: 92,640
Out: last fill done at 15,000 miles before friend bought the truck. Old fluid looked decent, brownish color with no metal bits.
In: Napa Premium GL-5 gear oil (2010 manual does not spec synthetic fluid)
- Joined
- Jan 23, 2024
- Messages
- 674
I plan on trying this on my wrx. Do you think it's a good idea?
I think Motul Gear 300 might be a favorite among wrx owners. But, Valvoline would be fine if it’s the right spec. 75w90 gl5 etc. I even think my Subaru dealer stocked Motul oil in-house for retail sale back in 2015.
2018 Subaru Crosstrek (Prem/NA 2.0 H4/6MT); see motor oil UOAs #1 here #2 here and #3 here.
72k miles
Replaced both trans/front diff oil and the rear diff oil
Rear diff
Out: ~0.8 qt Subaru GL-5 75w90 (factory fill)
In: ~0.8 qt Royal Purple MaxGear GL-5 75w90
The old oil came out a transparent golden-yellow with no visible sparkles (honestly it looked like new oil), with a small/medium amount of fine ferrous metal on the magnetic drain plug. I almost felt stupid for even having changed it. I'm a pretty sedate driver most of the time, apparently I didn't put much stress on the rear diff.
The maintenance schedule calls for this to be inspected every 30k with no replacement interval specified, but I don't know how you'd inspect it - drain it, look at it, and pump it back in if it looks good? In any case, I went with RP largely due to availability; the bottle I bought conveniently came with a little finger pump which was useful.
The only 'catch' came when I realized upon starting the job that I had a type 'T' diff rather than a type 'VA' or 'VB'; the upshot of this was that the 10mm hex bit I bought was not needed, the crush gaskets for the drain and fill plugs were not needed, and I needed to get a diff-oil-compatible liquid gasket compound (I went with Permatex). The procedure for replacement was pretty simple:
1. remove overflow/fill plug on back of diff case (13mm square drive, I used 1/2"/12.7mm and tried not to act like a gorilla)
2. put drain pan in place, remove drain plug on diff case and wait for old oil to drain
3. degrease threads and clean both plugs
4. apply liquid gasket to threads of drain plug
5. Reinsert drain plug, tightening by hand until ~snug
6. Pump new oil into diff through overflow plug hole until you get a dribble (should be 0.8qt, thankfully it was), then clean up the dribble
7. apply liquid gasket to threads of fill/overflow plug
8. Reinsert fill plug and hand-tighten until ~snug
9. Wait 1 hour for liquid gasket compound to do its thing (per instructions on Permatex packaging) before torquing
10. Torque both plugs to 36 lb-ft with torque wrench
I would have preferred the factory in Gunma had used the VA or VB rear diff on my car (unless something would have blown up as a result), as I much prefer using crush washers/gaskets to using the liquid gasket stuff. Weird that there are 3 rear diff types for the same car within one model year - I haven't been able to tell from NASIOC and other forums whether the choice was configuration-dependent (did all Crosstreks with 6MTs get the type T?), done based on using up stock after a design change, luck of the draw, etc. I didn't even realize the Type T existed based on the videos I used to research the job, until I was looking at my diff on the day I did it. Stupid on my part.
Transmission/front diff
Out: ~3.x qt Subaru "Extra MT" GL-5 75w80 (factory fill)
In: 3.3 qt Motul MotylGear GL-5 75w80
This was a completely nondescript drain-and-fill. I pulled out the dipstick, used a T70 Torx bit to get the drain plug out (no fight), drained, cleaned the plug and put on a crush gasket (there was none from the factory, but the snippet of the factory service manual I was using called for one), torqued to 51 lb-ft, and refilled through the dipstick hole. I used a funnel feeding another funnel feeding the dipstick hole to make it such that I could pour from a spot where I didn't have to contort myself. The manual calls for 3.5 US qt/ 3.3 liters for a full fill, but I was above the 'FULL' mark on the dipstick after 3.3 qt/3.1L so I stopped there; this has been reported by a lot of other folks who have drained-and-filled this transmission, so I'm not worried. Shifting feels maybe marginally better after the fluid change, but that might just be the placebo effect. The old fluid came out looking pretty clean with no sparkles and a low/medium amount of fine metal on the magnetic drain plug. I'll probably do this again at 120k, and maybe do a UOA on it then to see how my tranny is holding up. I would have done one on the factory fill that I drained here, but I drained the rear diff oil into the same pan without first emptying it so I couldn't meaningfully do so.
As an aside, the Subaru design for manual transmissions wherein there is:
* one unit that contains the transmission proper, the front diff (sharing oil with the transmission), and the viscous coupling center diff (a separate sealed unit-within-a-unit that doesn't share oil, but is probably bathed in it outside the seal)
* a longitudinal orientation (since the boxer engine has a longitudinal crankshaft) but two partly-captive axle half-shafts, making it arguable (at least to some) whether it is a transmission or a transaxle
is fascinating to me. I think all of them have been like this for at least 30 years.
Reference material:
72k miles
Replaced both trans/front diff oil and the rear diff oil
Rear diff
Out: ~0.8 qt Subaru GL-5 75w90 (factory fill)
In: ~0.8 qt Royal Purple MaxGear GL-5 75w90
The old oil came out a transparent golden-yellow with no visible sparkles (honestly it looked like new oil), with a small/medium amount of fine ferrous metal on the magnetic drain plug. I almost felt stupid for even having changed it. I'm a pretty sedate driver most of the time, apparently I didn't put much stress on the rear diff.
The maintenance schedule calls for this to be inspected every 30k with no replacement interval specified, but I don't know how you'd inspect it - drain it, look at it, and pump it back in if it looks good? In any case, I went with RP largely due to availability; the bottle I bought conveniently came with a little finger pump which was useful.
The only 'catch' came when I realized upon starting the job that I had a type 'T' diff rather than a type 'VA' or 'VB'; the upshot of this was that the 10mm hex bit I bought was not needed, the crush gaskets for the drain and fill plugs were not needed, and I needed to get a diff-oil-compatible liquid gasket compound (I went with Permatex). The procedure for replacement was pretty simple:
1. remove overflow/fill plug on back of diff case (13mm square drive, I used 1/2"/12.7mm and tried not to act like a gorilla)
2. put drain pan in place, remove drain plug on diff case and wait for old oil to drain
3. degrease threads and clean both plugs
4. apply liquid gasket to threads of drain plug
5. Reinsert drain plug, tightening by hand until ~snug
6. Pump new oil into diff through overflow plug hole until you get a dribble (should be 0.8qt, thankfully it was), then clean up the dribble
7. apply liquid gasket to threads of fill/overflow plug
8. Reinsert fill plug and hand-tighten until ~snug
9. Wait 1 hour for liquid gasket compound to do its thing (per instructions on Permatex packaging) before torquing
10. Torque both plugs to 36 lb-ft with torque wrench
I would have preferred the factory in Gunma had used the VA or VB rear diff on my car (unless something would have blown up as a result), as I much prefer using crush washers/gaskets to using the liquid gasket stuff. Weird that there are 3 rear diff types for the same car within one model year - I haven't been able to tell from NASIOC and other forums whether the choice was configuration-dependent (did all Crosstreks with 6MTs get the type T?), done based on using up stock after a design change, luck of the draw, etc. I didn't even realize the Type T existed based on the videos I used to research the job, until I was looking at my diff on the day I did it. Stupid on my part.
Transmission/front diff
Out: ~3.x qt Subaru "Extra MT" GL-5 75w80 (factory fill)
In: 3.3 qt Motul MotylGear GL-5 75w80
This was a completely nondescript drain-and-fill. I pulled out the dipstick, used a T70 Torx bit to get the drain plug out (no fight), drained, cleaned the plug and put on a crush gasket (there was none from the factory, but the snippet of the factory service manual I was using called for one), torqued to 51 lb-ft, and refilled through the dipstick hole. I used a funnel feeding another funnel feeding the dipstick hole to make it such that I could pour from a spot where I didn't have to contort myself. The manual calls for 3.5 US qt/ 3.3 liters for a full fill, but I was above the 'FULL' mark on the dipstick after 3.3 qt/3.1L so I stopped there; this has been reported by a lot of other folks who have drained-and-filled this transmission, so I'm not worried. Shifting feels maybe marginally better after the fluid change, but that might just be the placebo effect. The old fluid came out looking pretty clean with no sparkles and a low/medium amount of fine metal on the magnetic drain plug. I'll probably do this again at 120k, and maybe do a UOA on it then to see how my tranny is holding up. I would have done one on the factory fill that I drained here, but I drained the rear diff oil into the same pan without first emptying it so I couldn't meaningfully do so.
As an aside, the Subaru design for manual transmissions wherein there is:
* one unit that contains the transmission proper, the front diff (sharing oil with the transmission), and the viscous coupling center diff (a separate sealed unit-within-a-unit that doesn't share oil, but is probably bathed in it outside the seal)
* a longitudinal orientation (since the boxer engine has a longitudinal crankshaft) but two partly-captive axle half-shafts, making it arguable (at least to some) whether it is a transmission or a transaxle
is fascinating to me. I think all of them have been like this for at least 30 years.
Reference material:
I made a post on it, but figured I’d contribute here for posterity’s sake.
2014 Lincoln Navigator L 4x4
Ford 9.75” IRS Differential
Out: 2.5qts Amsoil Severe Gear 75w-140 with 20,000 miles on it.
In: 1/2qt HPL Differential Cleaner. 1qt Amsoil SG 75w-140, 1/2 qt Amsoil SG 75w-90, 1/2 qt Amsoil SG 80w-90. I just used up my remnants of Ams SG I had on the shelf as a carrier for the HPL Diff Cleaner.
Current mileage: 163,500. Will run this cleaner mix to 170,000 and post again.
2014 Lincoln Navigator L 4x4
Ford 9.75” IRS Differential
Out: 2.5qts Amsoil Severe Gear 75w-140 with 20,000 miles on it.
In: 1/2qt HPL Differential Cleaner. 1qt Amsoil SG 75w-140, 1/2 qt Amsoil SG 75w-90, 1/2 qt Amsoil SG 80w-90. I just used up my remnants of Ams SG I had on the shelf as a carrier for the HPL Diff Cleaner.
Current mileage: 163,500. Will run this cleaner mix to 170,000 and post again.
Did my M3 last month. Between the fluid swap and changing them temp sensor (which point straight down, sure to catch snow and ice) it took about 7 minutes and 1,5 qts of liqui moly. Plus a $15 sensor.
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