Manual Transmission Oil Supplier Guide for Importers

Begin with a vehicle and driveline application matrix

A useful sourcing brief starts with the equipment in the destination market. Record the vehicle make, model year, engine, transmission or axle code, sales channel and the requirement shown in current service information. This prevents a supplier from converting a mixed vehicle parc into one broad gear-oil recommendation that looks simple but cannot be defended at workshop level.

Separate synchronized passenger-car transmissions, transaxles, nonsynchronized heavy-duty manual transmissions, hypoid axles and limited-slip differentials. They may sit in the same catalogue category, yet their lubricant requirements and evidence routes are different. If the vehicle list is incomplete, mark those applications for confirmation rather than adding an unsupported universal claim to the label.

The supplier should return a coverage matrix showing the proposed product, SAE grade, service designation, application basis and any exclusions. For an importer, that matrix is more valuable than the number of products in a catalogue because it can support artwork, distributor training, technical enquiries and later range reviews.

Understand what GL-4 and GL-5 do—and do not prove

API Publication 1560 describes automotive gear-lubricant service designations and places the familiar labels in their historical and current context. It describes GL-4 in selected manual-transmission and transaxle service and GL-5 for gears, especially hypoid axle gears, operating under severe speed, shock-load or torque conditions. Those descriptions are application categories; they do not make one product an automatic substitute for another.

There is also an important evidence issue for buyers. API's ninth edition lists GL-4 among designations not in current use because the original verification hardware and procedures are unavailable, and it advises users who require GL-4 to request documentation for previously tested formulations. GL-5 remains current in the publication. This does not mean that every commercial GL-4 product is unsuitable; it means the importer should ask how the supplier substantiates that formulation and avoid presenting an unsupported API approval claim.

Do not approve wording such as GL-5 replaces GL-4 in all transmissions. The correct decision comes from the equipment requirement and the supplier's evidence for the exact formulation. If a gearbox manual permits more than one category, retain the source and conditions in the application matrix rather than converting a model-specific allowance into a global label statement.

• Review the FLYSAK GL-4 SAE 80W-90 product — See the current product profile, pictured pack options and document request path.

Treat SAE viscosity as a separate selection point

SAE J306 classifies automotive driveline lubricants by rheological limits. The current SAE page explicitly notes that other lubricant characteristics are not considered. In purchasing terms, SAE 75W-90, 80W-90, 85W-90 and 85W-140 identify viscosity behaviour; they do not by themselves establish GL performance, synchronizer suitability, limited-slip performance or an OEM approval.

Use the exact grade in the vehicle or equipment requirement. Climate and duty cycle may help explain why a manufacturer offers alternatives, but they should not be used to rewrite the service instruction. Ask the supplier to show the measured viscosity properties in the current TDS and sample COA and to identify the test methods used. Compare typical values as supporting data, not as proof of every driveline application.

When an RFQ covers several grades, keep the formulation and evidence package traceable to each commercial product. Similar bottle artwork can hide different service profiles, and a shared family TDS may not tell the buyer which formulation will actually be filled.

• Compare FLYSAK gear oil products — Review the current GL-4 and GL-5 product range by stated viscosity and pack reference.
• Review the FLYSAK GL-4 SAE 85W-90 product — Compare another current manual-gearbox product profile.

Use OEM lubricant lists as application evidence, not decoration

OEM and component-maker lubricant lists can be more specific than a broad API category. ZF, for example, maintains separate TE-ML lists for different units: TE-ML 01 covers specified manual truck transmissions, while TE-ML 11 covers particular passenger-car transmissions across several designs. The published lists identify the equipment scope and product entries, and current editions replace earlier ones.

For a buyer, the lesson is procedural. Ask which exact list, edition, unit family and product name support a claim. A statement that a product meets a ZF requirement is not equivalent to the product appearing under its commercial name on a current approval list. If the supplier provides a test report, approval letter or formulation cross-reference, record what it proves and when it must be rechecked.

Artwork should use only the wording supported by current evidence and destination-market rules. Do not add manufacturer logos or approval language merely because a similar viscosity appears in an OEM list. Recheck time-sensitive lists before every major artwork revision and before relying on them in a distributor tender.

Request a document pack that traces to the shipped product

The technical document pack should connect one commercial product name and formulation identifier to its TDS, SDS, performance evidence, written specification, sample COA and label. A generic certificate or an unrelated product report may be useful background, but it does not prove that the fluid in the approved bottle is the one reviewed for the claim.

The TDS should state the viscosity grade, intended application, supported service descriptions, representative properties and limitations. The SDS supports handling and transport decisions. The COA records agreed release checks for a particular batch; it does not replace the performance work used to support a GL or OEM statement. Keep those functions separate during supplier comparison.

Compare packaging and order structure on the same basis

A supplier quotation is meaningful only when the product, pack and commercial assumptions match. Compare the same formulation, fill volume, bottle, cap, induction seal, label material, carton, pallet arrangement, trade term and document scope. A lower price per litre may be offset by a different bottle specification, unused printed packaging or an order mix that does not fit the launch plan.

FLYSAK's current gear-oil catalogue shows multiple pack references across selected products, including small retail packs and larger workshop or bulk formats. Availability for a private-label programme should be confirmed against the exact product and artwork scope. Do not publish an MOQ, lead time or loading quantity until the supplier has confirmed it for that combination.

Approve a production-representative filled sample rather than only a digital label. Check bottle colour, resin, closure, seal, label position, print durability, batch coding and carton marking. If several viscosities share a visual system, make the grade and application differences difficult to confuse in a workshop or warehouse.

• Review the FLYSAK GL-5 SAE 85W-90 product — See a current axle and final-drive product profile and available pack references.

Control samples, batches and formulation changes

Before the first order, agree a written product specification and approve representative fluid and packaging samples. The production control plan should cover raw-material identification, formulation issue, blending records, in-process checks, filling controls, batch coding, retained samples and final release. The importer should know which values are checked on every batch and which performance evidence belongs to the approved formulation.

Define change control in writing. Changes in additive package, base oil, viscosity modifier, dye, formulation code, test method, bottle resin, closure, label stock or approval status can affect the evidence pack, artwork or market registration. Agree which changes need advance notice, updated documents, a fresh sample or written buyer approval.

A simple annual review is also useful. Vehicle coverage, OEM lists, standard editions and product documents can change even when the commercial name stays the same. Assign responsibility for reviewing those sources and correcting catalogues or distributor materials when an application is withdrawn or clarified.

Send an RFQ that exposes application gaps early

A strong RFQ includes destination countries, important vehicle or equipment families, transmission and axle codes, required SAE grades and service descriptions, pack sizes, label languages, sales channels, annual estimates and first-order mix. Attach current product labels if you are switching suppliers and identify any gearbox applications that regularly create customer questions.

Ask the supplier to return a proposed SKU map, evidence list, unsupported applications, sample plan, packaging options, batch-release approach and change-control terms. This makes gaps visible before price negotiation and prevents an attractive quotation from becoming an application problem after the product reaches workshops.

FLYSAK can review a buyer's manual-transmission and axle range against its current gear-oil catalogue and organise a private-label proposal around confirmed products and packaging. Every application and claim should still be checked against current documents before ordering or printing artwork.

• Review FLYSAK private-label support — See how product, packaging and buyer-document decisions are organised.
• Read the automatic transmission fluid supplier guide — Keep ATF, CVT, DCT and manual-gear sourcing decisions separate.
• Send your gear-oil sourcing brief — Share the application matrix, grades, pack sizes and proposed order mix.

Frequently asked questions