Pennzoil Dex/Merc Automatic Transmission Fluid — 1 Qt / 946 mL, DEXRON III/MERCON | 550050745
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The Pennzoil Automatic Transmission Fluid 550050745 is a high-quality mineral-oil ATF formulated for automatic transmissions, power-shift transmissions, transfer cases, power steering systems, hydraulic systems, and older applications requiring DEXRON III, MERCON, Allison C-4/C-3, or similar ATF performance. Pennzoil now identifies this product family as Pennzoil Dex/Merc ATF, reflecting its common DEXRON/MERCON service applications.
Key Features
- Pennzoil part number 550050745
- Container size: 1 quart / 946 mL
- Petroleum-based mineral automatic transmission fluid
- Designed for smooth, reliable transmission operation
- High oxidation resistance and shear stability
- Provides anti-wear and gear protection
- Helps protect components from corrosive acids
- Compatible with common seal materials
- Suitable for year-round use
- Commonly used in older passenger cars, trucks, buses, off-highway equipment, agricultural equipment, mobile hydraulic systems, transfer cases, power steering systems, and hydraulic applications
- Meets or exceeds historic GM DEXRON III, Ford MERCON, Allison C-4, Caterpillar TO-2, and related application requirements
Intended Use
Use this ATF where the equipment manufacturer specifies a DEXRON III, MERCON, Allison C-4/C-3, Caterpillar TO-2, or compatible automatic transmission fluid. It is commonly used in older automotive and light-truck transmissions, some marine-adjacent hydraulic or steering applications, power-shift transmissions, transfer cases, and mobile hydraulic systems where this fluid type is called for.
Fitment Notice
Always confirm the required fluid specification in the vehicle, engine, drive, transmission, steering, or hydraulic system manual before use. This fluid is intended for older DEXRON/MERCON-style applications and should not be used where a newer low-viscosity ATF, CVT fluid, dual-clutch fluid, Ford Type F fluid, or manufacturer-specific fluid is required.
When This Product Needs Replacement
Replace ATF when it is dark, burnt-smelling, contaminated, low, aerated, or no longer performing properly. Transmission service may also be needed if shifting becomes harsh, delayed, slipping, noisy, or inconsistent. Follow the equipment manufacturer’s service interval and fluid specification requirements.
Installation Notes
Drain and refill according to the equipment manufacturer’s service procedure. Avoid mixing fluid types unless the manual specifically permits it. Check the fluid level at the correct operating temperature and follow the proper dipstick, fill plug, or service-port procedure for the system being serviced. Dispose of used ATF responsibly.
Alternate/Superseded Part Numbers
Related references include:
- 550050745 — Pennzoil Automatic Transmission Fluid, 1 quart
- PEN 550050745 — common line/part reference
- SHE550050745 — Shell/Pennzoil catalog reference
- Pennzoil Dex/Merc ATF — current product-family naming
Parts Desk Insight
The key check with ATF is the specification, not just the bottle size. This product is a strong match for older DEXRON III/MERCON-style requirements, but newer transmissions can be very fluid-specific, so matching the manual before filling is the safer move.
Shipping: Ships same or next day for fast Canada wide shipping. ⚓
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 3–4 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.