---
product_id: 2219323
title: "50304 MT-90 75W-90 GL-4 Manual Transmission and Transaxle Lubricant (MTL)- 1 Quart"
brand: "redline oil"
price: "€ 56.48"
currency: EUR
in_stock: true
reviews_count: 11
category: "Red Line"
url: https://www.desertcart.sk/products/2219323-50304-mt-90-75w-90-gl-4-manual-transmission-transaxle
store_origin: SK
region: Slovakia
---

# Friction-optimized for quicker, smoother shifts 75W-90 viscosity for optimal gear protection GL-4 rated, safe for brass synchros, no corrosive sulfurs 50304 MT-90 75W-90 GL-4 Manual Transmission and Transaxle Lubricant (MTL)- 1 Quart

**Brand:** redline oil
**Price:** € 56.48
**Availability:** ✅ In Stock

## Summary

> ⚙️ Shift smoother, protect stronger — the gear oil pros swear by!

## Quick Answers

- **What is this?** 50304 MT-90 75W-90 GL-4 Manual Transmission and Transaxle Lubricant (MTL)- 1 Quart by redline oil
- **How much does it cost?** € 56.48 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.sk](https://www.desertcart.sk/products/2219323-50304-mt-90-75w-90-gl-4-manual-transmission-transaxle)

## Best For

- redline oil enthusiasts

## Why This Product

- Trusted redline oil brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Effortless Shifting:** Eliminates notchy, cold shifts for seamless driving
- • **Legacy of Excellence:** Red Line’s proven formula since 1979, no compromises
- • **Trusted Compatibility:** Perfect for GL-1, GL-3, and GL-4 manual transmissions
- • **Corrosion-Free Confidence:** Safe on brass synchros—no damage from reactive sulfurs
- • **Precision Gear Protection:** Extends synchro life with high-performance GL-4 formula

## Overview

Red Line 50304 MT-90 is a premium 75W-90 GL-4 manual transmission lubricant designed to protect gears and extend synchronizer life. Its friction-optimized formula ensures quicker, smoother shifts even in cold conditions, while being safe for brass synchros by avoiding harmful sulfurs found in GL-5 oils. Trusted since 1979, this 1-quart bottle delivers high-performance gear protection compatible with GL-1, GL-3, and GL-4 applications, making it a must-have for enthusiasts and professionals seeking reliable transmission care.

## Description

Buy Red Line 50304 MT-90 75W-90 GL-4 Manual Transmission and Transaxle Lubricant (MTL)- 1 Quart: Gear Oils - desertcart.com ✓ FREE DELIVERY possible on eligible purchases

Review: Miracle Juice! - I put this in a 2002 Chevy Tracker (rebadged Suzuki Vitara) with a 5 speed stick transmission and lever operated transfer case. The factory specification calls for a 75w90 GL4 gear lube in both but a previous owner had put GL5 rear end gear lube in them. GL5 eats at the "yellow metal" brass/bronze used in the gear synchronizers in the transmission and transfer case. As a result of this the transfer case would not shift into low range and the 5 speed stick was very tricky to shift. Hard shifts, having to force it into gear, being stiffer when it was cold, just overall not smooth. I was worried because a friend with a Jeep had a similar occurrence and ended up replacing his whole transmission because it became unshiftable and wouldn't hold gears. Read a review of this Redline and it's specific use for manual transmissions. Figured it couldn't hurt and put it in the transmission and transfer case. IMMEDIATELY it was smoother to shift just sitting in the garage with the engine off. I backed out of the garage and was able to promptly push it into 4lo for the first time since I have owned it. Worked great and I backed right up a small hill without any trouble. Several weeks later it's shifting better and low range is back. I will say the transmission was obviously damaged and the transfer case is still not smooth going into low range but I CAN go into low range now and the transmission is definitely smoother. I can only imagine what this stuff would be like in a transmission in better shape than mine. It's not cheap but considering how hard it is to find GL4 rated 75w90 anymore (I bet your local parts store doesn't have it or has a few quarts at most) I'd highly recommend this Redline product.
Review: Worth it - Used in my 2002 7.3 with a ZF6. This stuff is awesome transmission is quieter and shifts smooth. Just wish Redline used a bag instead of the hard bottle. It is a real pain to fill the case but worth it.

## 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 | B000CPCBEQ |
| Best Sellers Rank | #8,097 in Automotive ( See Top 100 in Automotive ) #14 in Gear Oils |
| Brand | Redline Oil |
| Customer Reviews | 4.9 4.9 out of 5 stars (2,847) |
| Date First Available | July 20, 2005 |
| Global Trade Identification Number | 00083522503044 |
| Is Discontinued By Manufacturer | No |
| Item Form | Fluids,Oil |
| Item Weight | 1.7 pounds |
| Item model number | 50304 |
| Liquid Volume | 32 Fluid Ounces |
| Manufacturer | Yukon Gear & Axle |
| Manufacturer Part Number | 50304 |
| Material | Brass |
| Model | MT90 75W90 GL4 QT |
| Number of Items | 1 |
| OEM Part Number | 50304 |
| Package Information | Bottle |
| Product Dimensions | 9 x 4 x 4 inches |
| Recommended Uses For Product | Lubricant,Lube |
| SAE J300 Viscosity Grade | 75W-90 |
| Specific Uses For Product | Lubricant for manual transmissions and transaxles, Prevent corrosion, Enable smooth shifting, Provide gear protection |
| UPC | 083522503044 |
| Unit Count | 32.0 Fluid Ounces |
| Viscosity | 75W90 |

## Product Details

- **Brand:** Redline Oil
- **Item Weight:** 1.7 Pounds
- **Liquid Volume:** 32 Fluid Ounces
- **Material:** Brass
- **Package Information:** Bottle

## Images

![50304 MT-90 75W-90 GL-4 Manual Transmission and Transaxle Lubricant (MTL)- 1 Quart - Image 1](https://m.media-amazon.com/images/I/61iZ6pnD7aL.jpg)

## Questions & Answers

**Q: Is anyone running this in an NV4500 long term? How does it hold up?**
A: I've been running it for 35,000 miles in my 1996 model GM NV4500 without issue.

**Q: Do I pour the entire contents directly in?  Are there any special instructions?**
A: To get maximum benefit of the Red Line you need to replace all the oil in the transmission.  For my car, it took 3.4 quarts so I bought four and filled it up until fluid was level with the bottom of the fill plug.  If you go to the Red Line website, they have which transmission oil is correct for your car and the capacity of the transmission so you will know how much you will need.

**Q: Is this product non-synthetic gl-3?**
A: Synthetic gl -4 oil

**Q: Can i use on 1992 chevy camaro rs?**
A: I would not. It is supposed to be OEM recommended for my 98 vw Cabrio 5speed. So Put $46 worth in and at0°F I could not shift the car until 30 minutes of idling. second Synchromesh was very fussy at 20deg

## Customer Reviews

### ⭐⭐⭐⭐⭐ Miracle Juice!
*by A***M on February 8, 2012*

I put this in a 2002 Chevy Tracker (rebadged Suzuki Vitara) with a 5 speed stick transmission and lever operated transfer case. The factory specification calls for a 75w90 GL4 gear lube in both but a previous owner had put GL5 rear end gear lube in them. GL5 eats at the "yellow metal" brass/bronze used in the gear synchronizers in the transmission and transfer case. As a result of this the transfer case would not shift into low range and the 5 speed stick was very tricky to shift. Hard shifts, having to force it into gear, being stiffer when it was cold, just overall not smooth. I was worried because a friend with a Jeep had a similar occurrence and ended up replacing his whole transmission because it became unshiftable and wouldn't hold gears. Read a review of this Redline and it's specific use for manual transmissions. Figured it couldn't hurt and put it in the transmission and transfer case. IMMEDIATELY it was smoother to shift just sitting in the garage with the engine off. I backed out of the garage and was able to promptly push it into 4lo for the first time since I have owned it. Worked great and I backed right up a small hill without any trouble. Several weeks later it's shifting better and low range is back. I will say the transmission was obviously damaged and the transfer case is still not smooth going into low range but I CAN go into low range now and the transmission is definitely smoother. I can only imagine what this stuff would be like in a transmission in better shape than mine. It's not cheap but considering how hard it is to find GL4 rated 75w90 anymore (I bet your local parts store doesn't have it or has a few quarts at most) I'd highly recommend this Redline product.

### ⭐⭐⭐⭐⭐ Worth it
*by M***W on September 14, 2025*

Used in my 2002 7.3 with a ZF6. This stuff is awesome transmission is quieter and shifts smooth. Just wish Redline used a bag instead of the hard bottle. It is a real pain to fill the case but worth it.

### ⭐⭐⭐⭐⭐ Good Stuff
*by D***N on January 2, 2026*

Good stuff!

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*Product available on Desertcart Slovakia*
*Store origin: SK*
*Last updated: 2026-02-01*