Decimari
Member
- First Name
- Reshad
- Joined
- Apr 28, 2022
- Threads
- 2
- Messages
- 19
- Reaction score
- 11
- Location
- Northern VA
- Car(s)
- 2021 Toyota Supra 3.0 Premium
- Thread starter
- #1
The leaking differential
I've run into an issue many others have run into which is seeing differential fluid seemingly leaking from the diff. Looking at the cooling fins on your differential you may be able to see oil gathered on the very bottom of the fins (you can see this if you just peak under the rear of the car without even lifting it). I had this issue and was worried the plug or seals were bad and needed to be replaced. I put the car in the air, opened the plug (Toyota PN# 90118-WA263), and pulled out ~1 liter (at 25k miles, 1 liter is what is recommended to fill a diff). I replaced the oil with Redline 75W85 GL-5 GEAR OIL which is what Redline recommends and replaced the plug with a new one.
Drivetrain vibrations on cold acceleration from full stop
The weather here is below 50 degrees Fahrenheit, I let my car go through its cat warm-up cycle and then drive. I noticed a vibration that could be described as feeling like drivetrain slack when accelerating from a stop. It kept bugging me knowing this was not something i've felt before. Some forum posts recommended doing very slow figure 8s, I did, nothing changed. It would go away after a few minutes of driving (assuming the diff oil got up to operating temps). I eventually got tired of it and bought the expensive oem fluid (Hypoid Axle Oil G4, BMW PN#83222447362). The fluid swap completely fixed the vibration/drive train slack feeling.
My conclusion (anecdotal)
Don't use Redline's diff oil if temps drop below 50 degrees Fahrenheit unless you don't care about the vibration/slack (I don't know if it causes damage though). Through some research on other forums, the differential has a vent that will vent pressure out. It is believed the diffs are overfilled from the factory and that results in the oil leaking. Easy way of verifying this is cleaning the diff's rear exterior, driving for some time and then looking under it to see if oil is found at points higher than the fill plug. If its only dirty directly under/around the plug, you got a leaky plug, if its above it, its more than likely just the vent. With this new fill, I have seen a small bit of oil coming out the vent but it is way way less than what I would see before.
TDLR
Driving under 50 degrees Fahrenheit? Use Hypoid Axle Oil G4, BMW PN#83222447362 (3 500ml bottles) and not Redline to avoid drivetrain vibrations/slack. Do you see Diff oil leaking? Its more than likely from the diff vent.
I've run into an issue many others have run into which is seeing differential fluid seemingly leaking from the diff. Looking at the cooling fins on your differential you may be able to see oil gathered on the very bottom of the fins (you can see this if you just peak under the rear of the car without even lifting it). I had this issue and was worried the plug or seals were bad and needed to be replaced. I put the car in the air, opened the plug (Toyota PN# 90118-WA263), and pulled out ~1 liter (at 25k miles, 1 liter is what is recommended to fill a diff). I replaced the oil with Redline 75W85 GL-5 GEAR OIL which is what Redline recommends and replaced the plug with a new one.
Drivetrain vibrations on cold acceleration from full stop
The weather here is below 50 degrees Fahrenheit, I let my car go through its cat warm-up cycle and then drive. I noticed a vibration that could be described as feeling like drivetrain slack when accelerating from a stop. It kept bugging me knowing this was not something i've felt before. Some forum posts recommended doing very slow figure 8s, I did, nothing changed. It would go away after a few minutes of driving (assuming the diff oil got up to operating temps). I eventually got tired of it and bought the expensive oem fluid (Hypoid Axle Oil G4, BMW PN#83222447362). The fluid swap completely fixed the vibration/drive train slack feeling.
My conclusion (anecdotal)
Don't use Redline's diff oil if temps drop below 50 degrees Fahrenheit unless you don't care about the vibration/slack (I don't know if it causes damage though). Through some research on other forums, the differential has a vent that will vent pressure out. It is believed the diffs are overfilled from the factory and that results in the oil leaking. Easy way of verifying this is cleaning the diff's rear exterior, driving for some time and then looking under it to see if oil is found at points higher than the fill plug. If its only dirty directly under/around the plug, you got a leaky plug, if its above it, its more than likely just the vent. With this new fill, I have seen a small bit of oil coming out the vent but it is way way less than what I would see before.
TDLR
Driving under 50 degrees Fahrenheit? Use Hypoid Axle Oil G4, BMW PN#83222447362 (3 500ml bottles) and not Redline to avoid drivetrain vibrations/slack. Do you see Diff oil leaking? Its more than likely from the diff vent.
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