This page lists 25 automatic transmission parts for the 2021 Honda Ridgeline, across 6 part types, covering the 3.5L V6 engine. Every part shows its brand, manufacturer part number and fitment notes.
The automatic transmission on the 2021 Honda Ridgeline covers the automatic gearbox and its supporting cast — filters, coolers, solenoids, mounts and torque-converter parts. The largest groups are Transmission Fluid (12 parts), Transmission Fluid Additive (5 parts) and Filter (4 parts). The other 3 part types cover the remaining 4 parts.
The 2021 Honda Ridgeline came with a single engine, the 3.5L V6, and every part is verified against it.
11 brands supply automatic transmission parts for the 2021 Honda Ridgeline, led by LUBEGARD (6 parts), VALVOLINE (4 parts) and VARIOUS MFR (3 parts), plus 8 more brands. Quality grades include Multi-Vehicle, Economy and ZF Fluid.
A "Popular" badge means the source catalog flagged the part as frequently chosen for the 2021 Honda Ridgeline. 4 parts have it, including ACDELCO 109243 (Transmission Fluid) and LUBEGARD 19610 (Transmission Fluid Additive). Each part number opens a page with every vehicle that part fits.
Case Vent
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| DORMAN | 14161 | 🇺🇸 US 🇨🇦 CA | View on Amazon |
This table covers the vents on a transmission or axle housing.
This group shows a single part: DORMAN 14161.
Drain Plug Gasket
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| DORMAN | 652530CD | 🇺🇸 US 🇨🇦 CA | 20 MMAt Transfer Case | View on Amazon |
This table covers the gaskets that seal the Drain Plug. Typical signs include seepage at the joint, a burnt-oil smell, or a leak that appears only after a long drive. Clean both flanges and torque in the sequence the notes or the manual call for.
This group shows a single part: DORMAN 652530CD.
Filter
Economy
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| VARIOUS MFR | PT99445 | 🇺🇸 US 🇨🇦 CA | In-Line | View on Amazon |
| VARIOUS MFR | PT99677 | 🇺🇸 US 🇨🇦 CA | Cartridge Filter | View on Amazon |
| VARIOUS MFR | PT99191 | 🇺🇸 US 🇨🇦 CA | Cartridge Filter | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| HASTINGS / BALDWIN | LOPRI | 🇺🇸 US 🇨🇦 CA | View on Amazon |
This table covers the replacement filters for this application — the table heading and notes say which circuit. Typical signs include restricted flow — long cranking, weak airflow, or dirty fluid after a short interval. Seat the new filter so it cannot bypass, and use the grade the notes call for.
4 Filter parts are listed for the 2021 Honda Ridgeline, from VARIOUS MFR and HASTINGS / BALDWIN.
In the Economy grade, VARIOUS MFR supplies 3 parts: the catalog's value-priced group. A representative part number is VARIOUS MFR PT99445.
The Standard Replacement section lists 1 option from HASTINGS / BALDWIN — built to original-equipment specification. HASTINGS / BALDWIN LOPRI is listed in this group.
Part numbers include VARIOUS MFR PT99445, VARIOUS MFR PT99677 and VARIOUS MFR PT99191, among others listed above.
Transmission Fluid
Dexron
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| ACDELCO Popular | 109243 | 🇺🇸 US | Container Type: Plastic Container | View on Amazon |
Multi-Vehicle
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| MOBIL Popular | 126505 | 🇺🇸 US 🇨🇦 CA | Multi-Vehicle ATF | View on Amazon |
| VALVOLINE Popular | VV3246 | 🇺🇸 US 🇨🇦 CA | Max Life Multi-Vehicle or Maxlife Multi-Vehicle Full Synthetic ATF1 Quart | View on Amazon |
| LIQUI MOLY | 20032 | 🇺🇸 US 🇨🇦 CA | Top Tec ATF 18001 Liter | View on Amazon |
| LIQUI MOLY | 22036 | 🇺🇸 US 🇨🇦 CA | Top Tec ATF 18005 Liter | View on Amazon |
| LIQUI MOLY | 20034 | 🇺🇸 US 🇨🇦 CA | Top TEC ATF 180020 Liter | View on Amazon |
| LUBEGARD | 69032 | 🇺🇸 US 🇨🇦 CA | 1 QuartComplete Full Synthetic ATF Fluid | View on Amazon |
| VALVOLINE | 773775 | 🇺🇸 US 🇨🇦 CA | Max Life Multi-Vehicle or Maxlife Multi-Vehicle Full Synthetic ATF1 Gallon | View on Amazon |
| VALVOLINE | 881051 | 🇺🇸 US 🇨🇦 CA | Maxlife Multi-Vehicle Full Synthetic ATF5 Gallon Bay Box | View on Amazon |
ZF Fluid
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| PENTOSIN | 1058111 | 🇺🇸 US 🇨🇦 CA | ATF91 Liter | View on Amazon |
| PENTOSIN | 1058211 | 🇺🇸 US 🇨🇦 CA | ATF95 Liters | View on Amazon |
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| VALVOLINE | 899179 | 🇺🇸 US 🇨🇦 CA | Extended Protection Full Synthetic ATF1 Quart | View on Amazon |
This table covers the automatic-transmission fluids specified for this gearbox. Typical signs include harsh or delayed shifts, fluid that smells burnt, or a shudder at light throttle. Use exactly the specification in the notes. Automatic transmissions are unforgiving of the wrong fluid.
12 Transmission Fluid parts are listed for the 2021 Honda Ridgeline, from VALVOLINE, LIQUI MOLY, PENTOSIN and 3 other brands. ACDELCO 109243 carries the "Popular" badge.
In the Dexron grade, ACDELCO supplies 1 part: grouped under the catalog's "Dexron" designation — the notes column spells out what sets them apart. A representative part number is ACDELCO 109243.
In the Multi-Vehicle grade, VALVOLINE, LIQUI MOLY, MOBIL and 1 other brand supply 8 parts: grouped under the catalog's "Multi-Vehicle" designation — the notes column spells out what sets them apart. A representative part number is MOBIL 126505.
In the ZF Fluid grade, PENTOSIN supplies 2 parts: grouped under the catalog's "ZF Fluid" designation — the notes column spells out what sets them apart. A representative part number is PENTOSIN 1058111.
1 ungrouped part is not assigned to a grade, with the same engine-level match.
Transmission Fluid Additive
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| LUBEGARD Popular | 19610 | 🇺🇸 US 🇨🇦 CA | Instant Shudder Fixx2 oz | View on Amazon |
| LUBEGARD | 60902 | 🇺🇸 US 🇨🇦 CA | Automatic Transmission Fluid Protectant10 oz | View on Amazon |
| LUBEGARD | 63010 | 🇺🇸 US 🇨🇦 CA | Platinum Universal ATF Protectant10 oz | View on Amazon |
| LUBEGARD | 63016 | 🇺🇸 US 🇨🇦 CA | Platinum Universal ATF Protectant15 oz | View on Amazon |
| LUBEGARD | 63032 | 🇺🇸 US 🇨🇦 CA | Platinum Universal ATF Protectant32 oz | View on Amazon |
This table covers the conditioners and additives used with this transmission fluid.
LUBEGARD supplies the 5 Transmission Fluid Additive parts for the 2021 Honda Ridgeline. LUBEGARD 19610 carries the "Popular" badge.
Part numbers include LUBEGARD 19610, LUBEGARD 60902 and LUBEGARD 63010, among others listed above.
Transmission Mount
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| ANCHOR | 10022 | 🇺🇸 US 🇨🇦 CA | Left | View on Amazon |
| DEA / MARMON RIDE CONTROL | A65100 | 🇺🇸 US 🇨🇦 CA | View on Amazon |
This table covers the mounts that hold the transmission to the chassis. Typical signs include a clunk on takeoff, a vibration at idle, or a separated rubber insert. Support the powertrain before unbolting a mount, and torque the fasteners in the notes.
2 Transmission Mount parts for the 2021 Honda Ridgeline come from 2 brands — ANCHOR and DEA / MARMON RIDE CONTROL.
This group includes ANCHOR 10022 and DEA / MARMON RIDE CONTROL A65100.
Buying Automatic Transmission Parts for a 2021 Honda Ridgeline
On this vehicle, the automatic transmission covers the automatic gearbox and its supporting cast — filters, coolers, solenoids, mounts and torque-converter parts.
- Confirm you have the 3.5L V6 engine — every part on this page is matched to it.
- Read the notes on each row for position, trim and spec qualifiers before you order.
- Where labor overlaps, replace the filter and pan gasket with every fluid service, and flush the cooler lines when replacing a failed unit.
- Cross-reference the manufacturer part number against your old part or a service-manual listing.
Start with the largest groups on this page: Transmission Fluid and Transmission Fluid Additive .
Frequently Asked Questions
How many automatic transmission parts fit the 2021 Honda Ridgeline?
Our catalog currently lists 25 automatic transmission parts for the 2021 Honda Ridgeline across 6 subcategories and 11 brands, covering the 3.5L V6 engine. Each part is matched to the engine(s) it fits.
What are the signs of automatic transmission problems on a 2021 Honda Ridgeline?
Common symptoms include delayed or harsh engagement, slipping under load, fluid that smells burnt, or shuddering at light throttle around 40 mph. If you notice any of these, identify the affected subcategory above and cross-reference the part numbers listed.
What should I replace at the same time?
Where labor overlaps, replace the filter and pan gasket with every fluid service, and flush the cooler lines when replacing a failed unit.
What do the market flags (US, CA, MX) on each part mean?
They show the market for which the manufacturer published application data for that part — where the vehicle was first sold, not where the part was made. If your 2021 Honda Ridgeline was originally sold in the US, the safest choice is a part marked for the US market.
How do I make sure a part fits my 2021 Honda Ridgeline?
Every part on this page is matched to the 3.5L V6 engine. Then use exactly the fluid specification in the notes — automatic transmissions are the least forgiving component on the vehicle about fluid choice. The notes column carries position and trim qualifiers where they apply.
Other Parts for the 2021 Honda Ridgeline
Automatic Transmission Parts for Other Honda Ridgeline Years
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