--- product_id: 7824058 title: "50305 MT-90 75W-90 GL-4 Manual Transmission and Transaxle Lubricant (MTL) - 1 Gallon" brand: "red line" price: "S$267" currency: SGD in_stock: true reviews_count: 13 url: https://www.desertcart.sg/products/7824058-50305-mt-90-75w-90-gl-4-manual-transmission-transaxle store_origin: SG region: Singapore --- # Friction formula for smoother, quicker shifts 75W-90 viscosity for optimal gear protection Safe on brass synchros, no reactive sulfurs 50305 MT-90 75W-90 GL-4 Manual Transmission and Transaxle Lubricant (MTL) - 1 Gallon **Brand:** red line **Price:** S$267 **Availability:** ✅ In Stock ## Summary > ⚙️ Shift smarter, drive smoother — the gear oil pros swear by! ## Quick Answers - **What is this?** 50305 MT-90 75W-90 GL-4 Manual Transmission and Transaxle Lubricant (MTL) - 1 Gallon by red line - **How much does it cost?** S$267 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.sg](https://www.desertcart.sg/products/7824058-50305-mt-90-75w-90-gl-4-manual-transmission-transaxle) ## 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 - • **Trusted Legacy:** Since 1979, Red Line delivers uncompromising performance and reliability - • **Synchro-Safe Formula:** No reactive sulfurs means zero brass synchro damage, guaranteed - • **Unmatched Gear Defense:** Extends synchro life with high-performance GL-4 protection - • **Versatile Compatibility:** Perfect for GL-1, GL-3, and GL-4 applications—one oil to rule them all - • **Seamless Shifting Experience:** Eliminates notchy shifts even in cold starts for flawless control ## Overview Red Line 50305 MT-90 is a premium synthetic 75W-90 GL-4 manual transmission and transaxle lubricant designed to protect gears and extend synchro life. Its unique friction formula ensures quicker, smoother shifts even in cold conditions, while its sulfur-free composition safeguards brass synchros from damage. Trusted since 1979, this 1-gallon bottle is a top-rated choice for GL-1, GL-3, and GL-4 applications, delivering professional-grade performance and reliability. ## Features - HIGH PERFORMANCE - gear protection and longer synchro life. Recommended for GL-1, GL-3, and GL-4 applications. - QUICKER SHIFTS - perfect synchronizer coefficient of friction and eliminates notchy shifting, even when cold - REQUIREMENTS - gear oil viscosity of 75W; 80W; SAE 40 10W40 and 15W40 motor oil - POPULAR GEAR OIL FOR - GL-1, GL-3 and GL-4 applications, as well as where most special synchromesh fluids are specified. Safe for brass synchros, as it lacks the reactive sulfurs found in most GL-5 oils that cause damage - WHY RED LINE - Established in 1979, Red Line Products perform & protect better than any on the market. No compromises. ## Technical Specifications | Specification | Value | |---------------|-------| | Asin | B002INX20C | | Best Sellers Rank | #2,203 in Automotive (See Top 100 in Automotive) #6 in Gear Oils | | Brand Name | Red Line | | Compatible Material | Brass Synchros | | Container Type | Bottle | | Customer Reviews | 4.9 4.9 out of 5 stars (5,072) 4.9 out of 5 stars | | Global Trade Identification Number | 00083522503051 | | Included Components | MT-90 75W-90 GL-4 | | Item Form | Fluids,Liquid,Oil | | Item Weight | 2.27 kg | | Liquid Volume | 128 fluid ounces | | Manufacturer | Red Line | | Material | Synthetic | | Model Number | 50305 | | Number Of Items | 1 | | Number Of Packs | 1 | | Part Interchange Info | 50305 | | Part Number | 50305 | | Recommended Uses For Product | Lube | | Sae J300 Viscosity Grade | 75W-90 | | Specific Uses For Product | Manual transmissions and transaxles | | Unit Count | 128 Fluid Ounces | | Upc | 083522503051 | ## Product Details - **Brand:** Red Line - **Item Weight:** 2.27 kg - **Liquid Volume:** 128 fluid ounces - **Material:** Synthetic - **Package Information:** Bottle ## Images ![50305 MT-90 75W-90 GL-4 Manual Transmission and Transaxle Lubricant (MTL) - 1 Gallon - Image 1](https://m.media-amazon.com/images/I/71oe7Mrgl5L.jpg) ## Available Options This product comes in different **Size, Number Of Items** options. ## Questions & Answers **Q: Can you mix gl-4 gear oil with gl-5 gear oil? what is difference? if do 50/50....will be good together? why or why not?** A: NO NO NO... GL-4 is specific for older transmissions that have bronze/brass parts. GL-5 will DESTROY these parts.. believe me I know from experience. My local speed shop mistakenly gave me GL-5 for my 91 YJ with the X-5 trans. Within ten miles I could smell the problem happening. They honored the mistake and gave me a gallon of correct GL-4 so at 150K my X5 was shifting much better. It's in the shop now at 185K for a trans rebuild (yeah it lasted THAT long) and Troy Transmissions was pleased to hear I wanted Redline. He insists on synthetics for Arizona heat and drivers who get in extreme conditions, look up the "back way to Crown King" for an idea of our kind of fun. And a heads up for the Y owners... beware the fast lube places. I went to two different shops and BOTH insisted GL-5 was the correct lube!!! NOT! Luckily the $450 they wanted just to change fluids scared me off and I did what Jeepers should do... work on your own rig yourself. **Q: why do many say to not change the old gear oil & that the "gunk" in old gear oil makes transmssion last longer & might have problems with new gear oil** A: What they are referring to is automatic transmission fluid. Automatic transmissions have a series of "bands" with clutch like materials bonded to the friction side. On a worn out automatic transmission, the friction materials on these bands are already smoothed out and slip. Since automatic transmission are driven by hydraulic pressure, the "gunk" suspended inside old fluid will help with "gripping" action with these band. This redline gear oil is used in Manual transmissions. The old saying would not apply here. **Q: Is MT 90 good for a 1995 jeep yj manual transmission?** A: Yes, great product; bought the vehicle used and it was not sure what type of fluid it had in the transmission. The jeep sounded like a bus and once I added the MT-90; big difference and most importantly much quietly. **Q: Is this product compatible with my 1975 vw beetle, type 1 which spec's 85w/90 gl-4 gear oil? or do you have a synthetic product that is?** A: I would look on the Volkswagen site or call a Volkswagen service department you can fool around with weights on engine oil but I wouldn't put the wrong weight in on a transmission ## Customer Reviews ### ⭐⭐⭐⭐⭐ Feel good *by on Reviewed in the United States June 28, 2026* I used this stuff to replace the old gear oil for my DC2 Integra ITR. No issues as if now. Shifts pretty good. ### ⭐⭐⭐⭐⭐ The only manual transmission oil I will ever buy anymore *by on Reviewed in the United States July 10, 2021* I have used this in three different vehicles over the years.First was a heavily modified and tuned 2008 Cobalt SS turbo with the F35 trans. I tracked that car often, including high speed courses, autocross, and the drag strip. The fluid held up fantastically, and always shifted smooth and accurately. I also used the SSlowbalt for my commute at the time, which was 120 miles a day @80-85mph.I have since (sadly) sold my SSlowbalt, and mostly drive my wife's previous (now mine) car, a moderately modified and tuned 2012 Cruze Eco with the M32 trans, that we bought brand new. I have used MT90 in that since the first trans fluid change at ~50k (150k miles at the time of writing this, was changed with the same fluid at 100k, and about to do a third change next week.)This stuff shifts SO SMOOTH! I wasn't having issues in my Cruze before I swapped the fluid, but I did, and still notice, how much nicer the shifting feels compared to my buddy's 2012 Cruze ECO 6MT. This is 100% worth it. I have driven our Cruze to both US coasts, through 39 states, ontario, and numerous drives back home to Detroit from Lincoln, NE. I also use my Cruze for the occasional autocross event. Just all around smooth and quiet operation.I also have this same fluid in my 1999 Jeep Wrangler TJ with 213k at the time of writing this.The MT90 smoothed it out to the point where I was worried, because I was so used to that old AX15 shifting like a dump truck, or something haha. But not anymore! Totally smooth, no grinding on faster shifts (1-2 used to grind a bit if I didn't remember I was driving a brick and tried to shift it too fast). Now it doesn't matter if I accidentally shift a bit too quickly, because there's absolutely no grind at all anymore!My TJ isn't a pavement princess. I use it for what it was made to do, and I use it a lot. That trans gets a regular workout. It has been about 15k miles since I swapped it.TL;DR: If you like your manual transmission to shift like butter, quiet, and precise, buy this fluid. ### ⭐⭐⭐⭐⭐ Scion grinding in 2nd or 3rd? This is what you need! *by on Reviewed in the United States June 26, 2026* Wow, I am shocked!So I've been dealing with my gears grinding in 2nd and 3rd for the past 1 1/2 Years in my manual 2005 Scion XA the car has had the problem since before i bought it, The previous owners replaced the clutch, And I'm assuming that someone had added extra gear oil, Because it spilled out when i took off the fill cap on ramps, I've been trying to figure out the grinding, For the past 2 years doing everything but trying to put a new clutch in, Previous owners also stated that the mechanic may have put the clutch in wrong, I guess he didn't, Because this nearly completely fixed the issue in under 200 miles of driving, Driving has also become much smoother, If you have a Scion XA i suggest changing to this oil regardless if your gears are grinding!You only need exactly 2 quarts for the Scion XA no more no less, I wish all m mechanics would look this up before adding too much oil!I found this out from reading forms on the Scion XA, Everyone suggested this oil for the grinding and regardless! So i hope someone sees it here! ## Frequently Bought Together - Red Line 50305 MT-90 75W-90 GL-4 Manual Transmission and Transaxle Lubricant (MTL) - 1 Gallon - Slippery Pete Fluid Pump for Gallon Bottles and Wide Mouth Quart Bottles (Not for Standard Quart Bottles) - Transfer Gear Oil, Transmission and Differential Fluid, Antifreeze with This 30cc Hand Pump - Red Line 57905 75W90 GL-5 Synthetic Gear Oil for Hypoid Limited Slip Differentials - 1 Gallon --- ## 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.sg/products/7824058-50305-mt-90-75w-90-gl-4-manual-transmission-transaxle](https://www.desertcart.sg/products/7824058-50305-mt-90-75w-90-gl-4-manual-transmission-transaxle) --- *Product available on Desertcart Singapore* *Store origin: SG* *Last updated: 2026-08-23*