--- product_id: 5797128 title: "Red Line 58204 Heavy Shockproof Gear Oil - 1 Quart" brand: "red line" price: "237.23 DT" currency: TND in_stock: true reviews_count: 13 category: "Red Line" url: https://www.desertcart.tn/products/5797128-red-line-58204-heavy-shockproof-gear-oil-1-quart store_origin: TN region: Tunisia --- # Longer drain intervals Race-proven performance Polyol ester synthetic base Red Line 58204 Heavy Shockproof Gear Oil - 1 Quart **Brand:** red line **Price:** 237.23 DT **Availability:** ✅ In Stock ## Summary > ⚡ Shift into the fast lane with Red Line’s shockproof gear oil! ## Quick Answers - **What is this?** Red Line 58204 Heavy Shockproof Gear Oil - 1 Quart by red line - **How much does it cost?** 237.23 DT with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.tn](https://www.desertcart.tn/products/5797128-red-line-58204-heavy-shockproof-gear-oil-1-quart) ## Best For - red line enthusiasts ## Why This Product - Trusted red line brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Proven Longevity:** Keeps transmissions quiet and smooth beyond 70,000 miles—experience durability that lasts. - • **Race-Ready Reliability:** Trusted by top-tier racing teams for Sprint, Midget, and NHRA applications. - • **Extreme Lubrication Power:** Fully synthetic polyol ester base ensures unmatched protection under the harshest conditions. - • **Smooth Shifting Experience:** Optimized for seamless gear transitions, perfect for high-performance motorcycles. - • **Maximized Differential Efficiency:** Engineered to boost mileage and reduce wear, surpassing API GL-5 standards. ## Overview Red Line 58204 Heavy Shockproof Gear Oil is a fully synthetic, polyol ester-based lubricant designed for extreme conditions. It enhances differential efficiency, extends drain intervals, and reduces wear, exceeding API GL-5 specifications. Popular among professional racers and high-performance motorcycle enthusiasts, it delivers smooth shifting and long-lasting protection. ## Description Product description Review: Great product - This is very good for Harley transmissions. Shifts smooth. Easy to find neutral. Review: the best gear trans fluid made in my opinion. - Don't trust anything better since its made for racecar transmissions. I have used in my Harley FXSTC transmission for 10 years and its at 77000 miles and still smooth and quiet. ## Features - FULLY-SYNTHETIC FORMULAS - created from polyol ester base stocks, offer excellent lubrication under extreme conditions - ENGINEERED TO PROVIDE - the highest degree of protection and improvement of differential efficiency for better mileage, longer drain intervals, and less wear, exceed API GL-5 specifications - NOT RECOMMENDED - for most synchro applications due to the product's extreme slipperiness - POPULAR GEAR OIL FOR - Many performance racing applications like Sprint, Midget, Dirt Late Model and Quick Change Differentials, Detroit Lockers and spools, NHRA Top Fuel and Funny Car rear ends, most popular ShockProof product, many racing and specialty applications - WHY RED LINE - Established in 1979, Red Line Products perform & protect better than any on the market. No compromises ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B000CPI5XW | | Best Sellers Rank | #24,180 in Automotive ( See Top 100 in Automotive ) #43 in Engine & Oil Fluid Additives | | Brand | Red Line | | Brand Name | Red Line | | Container Type | Bottle | | Customer Reviews | 4.8 out of 5 stars 1,002 Reviews | | Global Trade Identification Number | 00083522582049 | | Included Components | Red Line 58204 Heavy ShockProof Gear Oil - 1 Quart Bottle | | Item Form | Oil | | Item Type Name | Engine & Oil | | Item Weight | 1.7 Pounds | | Liquid Volume | 32 Fluid Ounces | | Manufacturer | Red Line | | Material | Synthetic | | Model Number | 58204 | | Number of Items | 1 | | Package Information | Bottle | | Part Interchange Info | 58204 | | Part Number | 57-6525 | | Recommended Uses For Product | Gear Oil | | Specific Uses For Product | Racing transmissions and transaxles, high load conditions, high-performance differentials | | UPC | 083522582049 083522582094 | | Unit Count | 32.0 Fluid Ounces | | Warranty Description | Limited Manufacturer | ## Product Details - **Brand:** Red Line - **Item Weight:** 1.7 Pounds - **Liquid Volume:** 32 Fluid Ounces - **Material:** Synthetic - **Package Information:** Bottle ## Images ![Red Line 58204 Heavy Shockproof Gear Oil - 1 Quart - Image 1](https://m.media-amazon.com/images/I/71GC5ofv8fL.jpg) ![Red Line 58204 Heavy Shockproof Gear Oil - 1 Quart - Image 2](https://m.media-amazon.com/images/I/81riZEsBuZL.jpg) ![Red Line 58204 Heavy Shockproof Gear Oil - 1 Quart - Image 3](https://m.media-amazon.com/images/I/81stu27RB+L.jpg) ![Red Line 58204 Heavy Shockproof Gear Oil - 1 Quart - Image 4](https://m.media-amazon.com/images/I/81owXIUH2ML.jpg) ![Red Line 58204 Heavy Shockproof Gear Oil - 1 Quart - Image 5](https://m.media-amazon.com/images/I/815nUM9tWEL.jpg) ## Questions & Answers **Q: What viscosity is this particular oil?** A: Film thickness greater than an SAE 75W250, yet low fluid friction like 75W90For heavily-loaded racing differentials and transmissions, problem gearboxesMany performance racing applications like Sprint/Midget/Dirt Late Model Differentials, Detroit Lockers and spools, NHRA Top Fuel and Funny Car rear endsNot recommended for most synchro applications due to the product's extreme slipperiness **Q: What is the viscosity of this? Need a specific number.** A: Film thickness greater than an SAE 75W250, yet low fluid friction like 75W90. This is from the manufacturer's site. **Q: Canged primary chain OIL of my 2002 RoadKing ScreamingEagle I made a MISTAKE! Added REDLINTransFluidw/Shockproof. IS It COMPATABLE** A: I would think not. As the primary runs a 20w 50 and the red line is something like 75 90 it's going to a lot thicker. I would call a local Indy not HD and ask them for sure. **Q: Is this GL5?** A: It exceeds API GL-5 specifications. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Great product *by D***O on January 3, 2026* This is very good for Harley transmissions. Shifts smooth. Easy to find neutral. ### ⭐⭐⭐⭐⭐ the best gear trans fluid made in my opinion. *by J***P on March 3, 2026* Don't trust anything better since its made for racecar transmissions. I have used in my Harley FXSTC transmission for 10 years and its at 77000 miles and still smooth and quiet. ### ⭐⭐⭐⭐⭐ Highly recommended for Subaru open diffs. *by T***Y on November 1, 2016* 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. ## Frequently Bought Together - Red Line 58204 Heavy Shockproof Gear Oil - 1 Quart - Red Line 42904 V-Twin Primary Case Oil, for use with UTVs, ATVs and Sportbikes - 1 Quart - K&N Motorcycle Oil Filter: High Performance, Premium, Designed to be used with Synthetic or Conventional Oils, Wrench Off Nut: Fits Select Harley Davidson Motorcycles, KN-171B --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.tn/products/5797128-red-line-58204-heavy-shockproof-gear-oil-1-quart](https://www.desertcart.tn/products/5797128-red-line-58204-heavy-shockproof-gear-oil-1-quart) --- *Product available on Desertcart Tunisia* *Store origin: TN* *Last updated: 2026-06-03*