Red Line 58209 Heavy ShockProof® Gear Oil - 946ml
Specialist Red Line full-synthetic gear lubricant for heavily loaded racing differentials, suitable non-synchronised transmissions, problem gearboxes and other wet-sump splash-lubricated drivetrain applications.
Heavy ShockProof® uses Red Line's unique suspension of microscopic solid particles to provide exceptionally high gear-tooth protection while keeping fluid drag comparatively low. Red Line describes the lubricant as behaving much like a liquid grease, allowing it to cushion gear teeth under extreme pressure and resist being thrown away from loaded surfaces.
The lubricant provides a film thickness greater than an SAE 75W250 gear oil while offering fluid friction more comparable with a 75W90. This combination makes Heavy ShockProof particularly suitable for highly loaded competition drivetrains where conventional gear oils may struggle to maintain adequate protection.
Typical Red Line applications include Sprint, Midget and Dirt Late Model differentials, quick-change differentials, Detroit Lockers and spools, and NHRA Top Fuel and Funny Car rear ends.
- Product type: Specialist full-synthetic high-load gear oil
- Product range: Heavy ShockProof®
- Brand: Red Line Synthetic Oil
- Product reference / SKU: 58209
- Container size: 946ml / 1 US quart
- Primary use: Heavily loaded racing differentials and transmissions
- Application type: Wet-sump / splash-lubricated drivetrain systems
- Film thickness: Greater than SAE 75W250
- Fluid friction: Comparable with approximately SAE 75W90
- Gear protection: Microscopic solid-particle ShockProof technology cushions gear teeth under extreme pressure
- Typical applications: Racing differentials, quick-change differentials, Detroit Lockers, spools and suitable non-synchro competition gearboxes
- Restriction: Not recommended for most synchronised manual transmissions
- System restriction: Avoid conventional pumps, coolers and fine filters unless specifically engineered for ShockProof lubricant
Fitment advice: Heavy ShockProof® is a specialist lubricant and should be selected according to gearbox or differential design rather than viscosity alone. It is primarily intended for heavily loaded, wet-sump and splash-lubricated racing or specialist drivetrain applications.
Important transmission note: Red Line does not recommend Heavy ShockProof® for most synchronised manual transmissions because its extreme slipperiness can prevent the synchronisers from generating the friction required for clean gear engagement.
Pumps, coolers & filters: ShockProof® lubricants contain a unique suspended medium that has a strong affinity for metal. Red Line advises against conventional pumped, filtered or cooled systems because this material can accumulate and potentially restrict small passages or filters.
Other items to consider: When servicing a gearbox or differential, you may also want to consider replacement drain and fill plug washers, seals, breathers and other drivetrain service components where required.
Useful tools / consumables: Fluid transfer pump or filling bottle where appropriate, drain pan, suitable sockets or spanners, torque wrench, protective gloves, workshop towels and brake cleaner for external clean-up.
Difficulty guide: DIY Difficulty: Moderate to Advanced. Filling the unit may be straightforward, but correct application selection is particularly important because Heavy ShockProof® is a specialist racing lubricant rather than a conventional universal gear oil.
Why Red Line? Red Line Synthetic Oil is known for high-performance lubricants, fluids and additives developed for demanding road, track and motorsport use. Red Line products are chosen by enthusiasts and workshops for their focus on protection, thermal stability, shift quality, friction control and application-specific performance.
What’s in the bottle: One 946ml / 1 US quart bottle of Red Line Heavy ShockProof® Gear Oil.
Service notes: Drain the existing lubricant and refill to the gearbox or differential manufacturer's specified level. Confirm that the unit is compatible with Heavy ShockProof® before use, particularly where synchronisers, pumps, coolers or filtration systems are fitted.
| Make | Model | Sub Variant | Chassis / Code | Years | Power (PS) | Engine Codes | Fuel | Transmission | Notes |
|---|---|---|---|---|---|---|---|---|---|
| Universal | Competition / specialist vehicles | Heavy-duty differential application | — | — | — | — | — | Differential | For heavily loaded racing, quick-change and specialist differentials including Detroit Lockers and spools. Designed for wet-sump / splash-lubricated systems. |
| Universal | Competition / specialist vehicles | Non-synchronised racing transmission | — | — | — | — | — | Racing gearbox | Suitable for appropriate heavily loaded non-synchro racing transmissions. Not recommended for most synchronised manual transmissions because of extreme slipperiness. |
| Vehicle Manufacturer | OEM Reference / Specification |
|---|---|
| Red Line | 58209 — Heavy ShockProof® Gear Oil, 946ml / 1 US quart UK/European reference |
| Red Line | Corresponding current US quart package reference: 58204 |
| Red Line | Film thickness greater than SAE 75W250 with fluid friction similar to 75W90 |
| Red Line | Microscopic suspended solid-particle ShockProof® technology provides low drag and high gear-tooth protection |
| Red Line | For heavily loaded racing differentials, transmissions and problem gearboxes |
| Red Line | Recommended applications include circle track, road racing, drag racing, off-road and other wet-sump splash-lubricated systems |
| Red Line | Typical applications include Sprint, Midget, Dirt Late Model and quick-change differentials, Detroit Lockers and spools, and NHRA Top Fuel / Funny Car rear ends |
| Application restriction | Not recommended for most synchronised manual transmissions because of the product's extreme slipperiness |
| System restriction | Avoid conventional pumps, coolers and filters unless the system is specifically engineered for ShockProof® lubricant |
| Universal application | No direct vehicle-manufacturer OE replacement reference; specialist aftermarket high-load racing gear lubricant |