Updated thoughts on AX-15 lube?

[Mr_Xv3]

Long time listener, first time caller…

My wife and I have a 1999 Jeep Cherokee 4x4 Sport with the AX-15. For those not aware, Chrysler updated the spec fluid to 10w30 motor oil after 75w90 GL3 gear oil became more difficult to find - these gearboxes are sensitive to sulphur as they have "yellow metal" synchros.

In the past, I had used RP 10w40 based on Jeep forum recommendations and been pleased with the shifting performance. Recently, there seems to be an increase in Xw40 options… PU, Castrol Edge, and M1. Due to us owning 2x BMWs calling for LL01 spec oil, I keep GC and Edge 0w40 around the house. My question for the experts - is there a better choice? To drive towards even more commonality - would Edge 0W40 be a good choice for the Jeep 242 (4.0L) as well? I am currently using T6 5w40 based on the great used oil analysis posted here but if the experts feel there is merit, I may make a complete shift.

Thanks!

 

[LargeCarManX2]

Amsoil Manual Transmission & Transaxle Gear Lube 75W-90


Manual Transmission & Transaxle Gear Lube 75W-90

Formulated specifically for demanding manual transmission and transaxle applications
Product Code: MTGQT-EA




Package sizes include:

•Quart Bottle
•5-Gallon Pail
•55-Gallon Drum


WarrantyMSDSData Sheet

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Towing, heavy hauling and performance driving create shock-loading conditions and elevated heat that threaten the performance and life of manual transmissions and transaxles. Making matters worse, horsepower, torque and towing capacities seem to increase with each new vehicle model year, increasing severity. AMSOIL Synthetic Manual Transmission & Transaxle Gear Lube is specifically formulated to reduce friction and maintain viscosity for long component and fluid life. It is designed to excel in severe-service conditions that exceed the limitations of conventional fluids.

Protects Against Wear & Heat in Severe Applications
Synthetic Manual Transmission & Transaxle Gear Lube is shear-stable and maintains its viscosity despite rigorous mechanical action. It provides a thick lubricating film and contains extreme-pressure additives to protect against wear in severe-service and shock-loading conditions common when towing or hauling. It resists thermal degradation and oxidation for excellent performance in high-temperature applications, such as the New Venture NV-4500 transmission, which retains heat due to its cast-iron housing and is often subject to increased torque from turbodiesel engines.

Quick Shifts & Excellent Protection in Hot Rods and Muscle Cars
Synthetic Manual Transmission Gear Lube's friction-modified formula and excellent cold-flow properties promote smooth, fast engagement of synchronizers and gears. It protects against wear caused by the high-horsepower, large-displacement engines common to hot rods and muscle cars. It is formulated with seal conditioners to reduce leaks.

Promotes Longevity in Front-Wheel-Drive Transaxles
Synthetic Manual Transmission Gear Lube meets 75W/80W-90 viscosity requirements and exceeds API GL-4 performance requirements for many front-wheel-drive vehicles. Its excellent gear protection, extreme-temperature performance and durability promote maximum longevity and reduced maintenance costs.
•Protects against increased heat and pressure
•Outstanding cold-flow properties
•Protects brass synchronizers
•Friction-modified
•Excellent seal compatibility
•Inhibits rust and corrosion
•Long service life

Applications
Synthetic Manual Transmission & Transaxle Gear Lube is recommended for applications requiring a 75W-85, 75W-90 or 80W-90 viscosity gear oil with any of the listed specifications:
•API GL-4
• Chrysler MS-9070
• ZF TE-ML 02b, 17a
• MAN 341-Z2 (formerly MAN 341 ML)
• MB 235.5

Replaces GM part #12346190 and Chrysler part #4874459. Examples of transmissions and transaxles requiring a 75W-90, API GL-4 lubricant include certain models of Hyundai, Infiniti, Kia, Lexus, Mazda, Mitsubishi, Nissan, Suzuki, Toyota, Volkswagen and Hino

 

[JamesBond]

I could never get my 98 xj to shift very well. I even tried some mopar fluid from the dealer, to no avail. You may want to try pennzoil synchromesh. It's on the thin side spec wise but seems to work in newer jeep manuals. If I still had an xj it's what I would try.

 

[askani79705]

Red line MT-90 GL-4 . Low Sulfur so it's OK for brass syncronizers

 

[caravanmike]

as the owner of a 91 yj with an ax-5 i have 10w30 in it, but i here some running pennzoil syncromesch with good results.

 

[Mr_Xv3]

I appreciate everyone's input… unfortunately, neither Amsoil or RL are readily available for me locally/retail.

Rewording the original question: Mopar has updated the recommended fill for late AX-15s to 10w30 (synthetic ok) motor oil as the fill - is there any benefit to using 10w40 synthetic or even a 0w40 synthetic? IF so - which one would you choose (Castrol, PU, M1, etc)?

I have been pleased with RL products in the past… and use them in my BMWs. BUT, with the OE manufacturer now specifying a non-gear oil with similar viscosities - is there an advantage that MT-90 provides that warrants a 50% increase in cost?

 

[Ramblejam]

Originally Posted By: Mr_Xv3
which one would you choose


Valvoline Synchromesh MTF.

It's what Valvoline recommends for this application, and is available locally for $7.99/quart from either NAPA or O'Reilly.