







⚡ Gear up with Red Line – where performance meets precision!
Red Line 58204 Heavy ShockProof Gear Oil is a fully-synthetic, polyol ester-based lubricant designed to deliver superior protection and efficiency for high-performance differentials. Exceeding API GL-5 specs, it extends drain intervals and reduces wear, making it the go-to choice for professional racing and specialty applications since 1979.






| Manufacturer | Red Line |
| Brand | Red Line |
| Product Dimensions | 22.86 x 9.88 x 9.83 cm; 771.11 g |
| Item model number | 58204 |
| Exterior | Painted |
| Manufacturer part number | 58204 |
| OEM Part Number | 58204 |
| Item Weight | 771 g |
| Viscosity | Viskositätsindex (VI) |
J**E
Eliminated all crunch’s/missed gear changes.
Used to have a crunch sometimes when changing into 3rd or 4th, since putting this stuff in my 850hp r33gtr I’ve not had one missed change even when hard launching at santapod raceway.
S**Y
Used all over the world where you need the best protection and maximum strength
No need to say anything about this. Used all over the world where you need the best protection and maximum strength, there is no better. I use it in BMW shaft drive final drives and boxer gearboxes. Ideal for use in BMW R1200GSA or GSs that travel heavy and run for long periods at high speed or in very hot climates.
F**E
Wicked Stuff!
This is gearbox magic. I race my Honda DC2 way too regularly :) and far too aggressively if I'm honest. It used to have a 3rd gear synchro crunch and after doing a fluid change and adding this magic stuff it's totally cured it (18 months in) still no crunch. The box and gear changes are brilliant
A**E
Makes all the difference
Huge improvement, this oil is transforming the bike
M**N
Quality
Very happy with this worked well
J**Y
great seller. great
this is my second order, great seller. great item
W**Z
Slippery
Used in Moto Guzzi rear drive on Triking
M**S
Five Stars
good buy
N**C
Questo olio per differenziale è veramente fantastico e mantiene ciò che promette. E' bene ricordare che è un olio per differenziale e non va usato nei cambi con sincronizzatori. Leggere le indicazioni di utilizzo e la scheda tecnica, sono chiare e ben fatte.
3**0
My 3rd gear synchro was failing and grabbing and gridning getting in to gear, after a bit of reading I decided to try this and it fixed my gearbox and saved me $1000s.
T**Y
Used this in my 1999 Subaru Impreza Outback Sport with noisy front and rear differentials. I threw some mobil0-1 75w-90 in each diff for about 1k miles to rinse things out. Just dropping the beat-up, dark diff fluid and going to Mobil 1 was a marked improvement alone. After running that sacrificial fluid for 1k miles, I drained it (and it was in much better shape, but still appeared QUITE DIRTY) and installed some Lucas full synthetic 75w-90 gear oil with about a half of the Heavy Shockproof quart going into the front and a half going into the rear diff. I put the Redline in first so it would mix better. Both my front and rear differentials are OPEN (not LSD; if you have an LSD, DO NOT USE this redline shockproof series). Immediately, I noticed that the diffs were notably quieter and that the car even accelerated and coasted more easily than even with the mobil-1 gear oil. I used the heavy shockproof because I'm in Florida and it never gets very cold here (it dips below freezing for a few hours, a few nights of the year, but only just below). If you are not in a southern state (FL, Texas, AZ, NM, LA, etc), I would advise selecting the lightweight shockproof instead. Overall, I'm extremely satisfied. If you have an open diff, or an air locker (anything but an LSD), you owe it to yourself to add a portion of shockproof to your diff. Quieter means cooler. That's always a good thing. Also, NEVER add this to any transmission. Even a manual. Your synchros will be permanently too slippery to work properly.
P**L
The best lube for Harley-Davidson Transmissions , quiets shift & makes finding neutral effortless!
R**!
It is awesome... buy some today. I put this in my Baker 6 speed on my custom V Twin... So far so good....
Trustpilot
2 weeks ago
5 days ago