---
product_id: 7824058
title: "Red Line 50305 MT-90 75W-90 GL-4 Manual Transmission and Transaxle Lubricant (MTL) - 1 Gallon"
brand: "red line"
price: "VT56412"
currency: VUV
in_stock: true
reviews_count: 11
category: "Red Line"
url: https://www.desertcart.vu/products/7824058-red-line-50305-mt-90-75w-90-gl-4-manual
store_origin: VU
region: Vanuatu
---

# Faster, smoother shifts even in cold temps 75W-90 viscosity for optimal gear protection Safe on brass synchros, no reactive sulfurs Red Line 50305 MT-90 75W-90 GL-4 Manual Transmission and Transaxle Lubricant (MTL) - 1 Gallon

**Brand:** red line
**Price:** VT56412
**Availability:** ✅ In Stock

## Summary

> ⚙️ Shift smoother, last longer—drive with confidence and style!

## Quick Answers

- **What is this?** Red Line 50305 MT-90 75W-90 GL-4 Manual Transmission and Transaxle Lubricant (MTL) - 1 Gallon by red line
- **How much does it cost?** VT56412 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.vu](https://www.desertcart.vu/products/7824058-red-line-50305-mt-90-75w-90-gl-4-manual)

## 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

- • **DIY Friendly:** Easy fill ports and no filter needed—upgrade your ride hassle-free
- • **Trusted Legacy:** Red Line’s proven performance since 1979—no compromises
- • **Effortless Shifting:** Eliminates notchy shifts for buttery smooth gear changes
- • **All-Weather Reliability:** Maintains perfect friction coefficient from cold start to high temps
- • **Unmatched Gear Longevity:** Extends synchro life with high-performance GL-4 formula

## 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. It ensures quicker, smoother shifts even in cold conditions by optimizing friction coefficients and is safe for brass synchros due to its non-reactive sulfur formula. Trusted since 1979, this 1-gallon bottle offers professional-grade performance favored by enthusiasts and pros alike, making it the go-to choice for manual transmission maintenance and peak driving experience.

## Description

Buy Red Line 50305 MT-90 75W-90 GL-4 Manual Transmission and Transaxle Lubricant (MTL) - 1 Gallon: Gear Oils - desertcart.com ✓ FREE DELIVERY possible on eligible purchases

Review: 1st gen tacoma gold - 2003 Toyota Tacoma 2.7L - 4x4 - 5spd manual Box was well packaged and sealed in a plastic bag (think mine was double layer plastic). By far the best fluid to run in the manual transmission and transfer case. Seriously avoid supertech (walmarts fluid - especially in the differentials). The first time I put this in, I did a flush with walmarts cheap sythentic fluid (75w-90 supertech) for 200miles just to make sure all the metal was out. I would not recommend more than 500 to 2,000 miles on supertech. With supertech synthetic, I accidentally ended up putting 7000 miles on the rear differential which is a higher torque spindle-type differential in most trucks and the temps were incredibly bad. > 180F @ regular 90mph. Really you shouldn't take most spindle type differentials above 75-80mph because of the wear. With amsoil the rear diff dropped down to 120 for the first 15miles and then around 140 at 90mph. - this is with outside temps of 85+. No more steel flaking and rusting. I'd use amsoil in the transfer case and manual transmission but it's not as good as this stuff at the varying temps. + the transmission doesn't get hot like a rear diff with 210,000 miles. And the transfer case barely sees any speed or wear even at the highest mphs. Thank god for brass. Drain bolts are 24mm. I used a tekton 2ft breaker bar and a shallow 24mm socket. Also bought the u-joints for ratchets just in case. Best fluid (lowest temps & smooth) I've found for the differential is amsoil severe gear 75-110 (yes I know the manual calls for 75w-90). Also, 75w-140 has very weird properties. So bigger numbers are not always better. Used valvoline dextron VI for power steering, which is meh after 10k miles. Will change to amsoil. Mobile1 seems best in the engine from a cost and wear perspective. I usually get pennzoil full synthetic because mobile1 is sold out. Pennzoil is nearly as good for the first 3,500 then seems to degrade much faster. Every truck varies. My rear differentials were probably neglected from the previous owner and exceeding the payload rating numerous times or perhaps someone possibly did not try too hard to get the perfect backlash / etc from the factory. These are my recommended milage drain marks: 15,000-25,000 rear diff 30,000+ front diff (will likely look good for you) 25,000 transmission 40,000-60,000 transfer case (unless this takes you years as in acid is more of a factor than viscosity) 30,000 for power steering 7,000 for engine Brake fluid 2 years if you dare :p Save yourself $150-$400, help your car, and buy the good fluid and do the transmission, transfer case, and rear differential yourself. It's easier than an oil change. No filter required. Fill ports offer idiot proof over/under filling assuming you're on level ground. I do it in the walmart parking lot with a 7qt oil container. Some brake cleaner. Scotts shop towels. Gloves (yes plz). Some empty distilled water containers. And a funnel. Might need a partner to hold the empty containers up while you pour the used oil. The front differential requires 10mm and 12mm hex to ratchet attachments and is much more tricky to access. Worth it though. :)
Review: Worth the price. - Get what you pay for, though pricey, irrefutable 'performance' gains: vehicle shifts much much much more smoothly now - no more 'crunchy' shifts, & all gears operate better in a wider range of temps as well. Prior to the fluid change, 1st & Reverse were the more difficult gears to get in to, especially in colder weather - before the fluid had a chance to warm up - now they all shift smooth as butter. I can also shift much faster as a result. Last little + is that the fluid doesn't smell horrid.

## 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 | #7,275 in Automotive ( See Top 100 in Automotive ) #12 in Gear Oils |
| Brand | Red Line |
| Customer Reviews | 4.8 4.8 out of 5 stars (1,685) |
| Date First Available | July 3, 2012 |
| Global Trade Identification Number | 00083522503051 |
| Is Discontinued By Manufacturer | No |
| Item Form | Fluids,Liquid,Oil |
| Item Weight | 4.99 pounds |
| Item model number | 50305 |
| Liquid Volume | 128 Fluid Ounces |
| Manufacturer | Red Line |
| Manufacturer Part Number | 50305 |
| Material | Synthetic |
| Model | 50305 |
| Number of Items | 1 |
| OEM Part Number | 50305 |
| Package Information | Bottle |
| Product Dimensions | 7.5 x 4 x 11.25 inches |
| Recommended Uses For Product | Lube |
| Specific Uses For Product | Manual transmissions and transaxles |
| UPC | 083522503051 |
| Unit Count | 128.0 Fluid Ounces |

## Product Details

- **Brand:** Red Line
- **Item Weight:** 2.27 Kilograms
- **Liquid Volume:** 128 Fluid Ounces
- **Material:** Synthetic
- **Package Information:** Bottle

## Images

![Red Line 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** 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

### ⭐⭐⭐⭐⭐ 1st gen tacoma gold
*by M***N on January 10, 2017*

2003 Toyota Tacoma 2.7L - 4x4 - 5spd manual Box was well packaged and sealed in a plastic bag (think mine was double layer plastic). By far the best fluid to run in the manual transmission and transfer case. Seriously avoid supertech (walmarts fluid - especially in the differentials). The first time I put this in, I did a flush with walmarts cheap sythentic fluid (75w-90 supertech) for 200miles just to make sure all the metal was out. I would not recommend more than 500 to 2,000 miles on supertech. With supertech synthetic, I accidentally ended up putting 7000 miles on the rear differential which is a higher torque spindle-type differential in most trucks and the temps were incredibly bad. > 180F @ regular 90mph. Really you shouldn't take most spindle type differentials above 75-80mph because of the wear. With amsoil the rear diff dropped down to 120 for the first 15miles and then around 140 at 90mph. - this is with outside temps of 85+. No more steel flaking and rusting. I'd use amsoil in the transfer case and manual transmission but it's not as good as this stuff at the varying temps. + the transmission doesn't get hot like a rear diff with 210,000 miles. And the transfer case barely sees any speed or wear even at the highest mphs. Thank god for brass. Drain bolts are 24mm. I used a tekton 2ft breaker bar and a shallow 24mm socket. Also bought the u-joints for ratchets just in case. Best fluid (lowest temps & smooth) I've found for the differential is amsoil severe gear 75-110 (yes I know the manual calls for 75w-90). Also, 75w-140 has very weird properties. So bigger numbers are not always better. Used valvoline dextron VI for power steering, which is meh after 10k miles. Will change to amsoil. Mobile1 seems best in the engine from a cost and wear perspective. I usually get pennzoil full synthetic because mobile1 is sold out. Pennzoil is nearly as good for the first 3,500 then seems to degrade much faster. Every truck varies. My rear differentials were probably neglected from the previous owner and exceeding the payload rating numerous times or perhaps someone possibly did not try too hard to get the perfect backlash / etc from the factory. These are my recommended milage drain marks: 15,000-25,000 rear diff 30,000+ front diff (will likely look good for you) 25,000 transmission 40,000-60,000 transfer case (unless this takes you years as in acid is more of a factor than viscosity) 30,000 for power steering 7,000 for engine Brake fluid 2 years if you dare :p Save yourself $150-$400, help your car, and buy the good fluid and do the transmission, transfer case, and rear differential yourself. It's easier than an oil change. No filter required. Fill ports offer idiot proof over/under filling assuming you're on level ground. I do it in the walmart parking lot with a 7qt oil container. Some brake cleaner. Scotts shop towels. Gloves (yes plz). Some empty distilled water containers. And a funnel. Might need a partner to hold the empty containers up while you pour the used oil. The front differential requires 10mm and 12mm hex to ratchet attachments and is much more tricky to access. Worth it though. :)

### ⭐⭐⭐⭐⭐ Worth the price.
*by Z***. on February 5, 2026*

Get what you pay for, though pricey, irrefutable 'performance' gains: vehicle shifts much much much more smoothly now - no more 'crunchy' shifts, & all gears operate better in a wider range of temps as well. Prior to the fluid change, 1st & Reverse were the more difficult gears to get in to, especially in colder weather - before the fluid had a chance to warm up - now they all shift smooth as butter. I can also shift much faster as a result. Last little + is that the fluid doesn't smell horrid.

### ⭐⭐⭐⭐⭐ For manual transmission GL-4
*by A***. on December 14, 2025*

I had trouble finding a GL-4 manual transmission fluid and I think this is a very good product. However I think it's overpriced, but so are most other things in life. This actually smells like transmission fluid and not gear oil. Time will tell how good of a product it is. I want to give 4 stars because I think it's overpriced, but since it's less expensive than Toyota I'll still give it 5 stars

## 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.vu/products/7824058-red-line-50305-mt-90-75w-90-gl-4-manual](https://www.desertcart.vu/products/7824058-red-line-50305-mt-90-75w-90-gl-4-manual)

---

*Product available on Desertcart Vanuatu*
*Store origin: VU*
*Last updated: 2026-03-10*