This page lists 21 automatic transmission parts for the 1961 Checker Marathon, across 11 part types, covering both the 3.7L 226cid L6 and the 5.2L 318cid V8. Every part shows its brand, manufacturer part number and fitment notes.
On the 1961 Checker Marathon, the automatic transmission covers the automatic gearbox and its supporting cast — filters, coolers, solenoids, mounts and torque-converter parts. Most of the listed parts are Extension Housing Seal (4 parts), Fluid Pump Seal (4 parts) and Manual Shaft Seal (2 parts). The other 8 part types cover the remaining 11 parts.
The 1961 Checker Marathon was sold with both the 3.7L 226cid L6 and the 5.2L 318cid V8. 20 parts fit every engine; the other 1 is engine-specific. Each part shows which engine(s) it fits.
6 brands supply automatic transmission parts for the 1961 Checker Marathon, led by SKF (6 parts), TIMKEN (4 parts) and WJB / INMOTION PARTS (4 parts), plus 3 more brands.
Each part number listed for the 1961 Checker Marathon opens a page with every vehicle that part fits.
Extension Housing Repair Sleeve
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| TIMKEN Fits: all 1961 Marathon engines | KWK99156 | 🇺🇸 US | Kwik-Sleeve | View on Amazon |
This table covers the wear sleeves used to restore a Extension Housing seal surface.
This group shows a single part: TIMKEN KWK99156.
Extension Housing Seal
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| BCA Fits: all 1961 Marathon engines | NS473234 | 🇺🇸 US | with T12 Transmission Code | View on Amazon |
| NATIONAL Fits: all 1961 Marathon engines | 473234 | 🇺🇸 US | with 3-Speed Borg Warner T12 Transmission | View on Amazon |
| TIMKEN Fits: all 1961 Marathon engines | 8160S | 🇺🇸 US | View on Amazon | |
| WJB / INMOTION PARTS Fits: all 1961 Marathon engines | WS473234 | 🇺🇸 US | with 3-Speed Borg Warner T12 Transmission | View on Amazon |
This table covers the seals at the Extension Housing. Typical signs include a wet housing, a drip after sitting, or fluid flung off a rotating shaft. Fix the surface the seal rides on. A new seal on a grooved shaft will leak again.
4 Extension Housing Seal parts for the 1961 Checker Marathon come from 4 brands — BCA, NATIONAL, TIMKEN and 1 other brand. Every part fits both the 3.7L 226cid L6 and the 5.2L 318cid V8.
Part numbers include BCA NS473234, NATIONAL 473234 and TIMKEN 8160S, among others listed above.
Fluid Pump Repair Sleeve
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| WJB / INMOTION PARTS Fits: all 1961 Marathon engines | WS99193 | 🇺🇸 US | Frontwith 3-Speed Borg Warner T12 Transmission | View on Amazon |
This table covers the precision wear sleeves used to restore a transmission pump seal surface.
This group shows a single part: WJB / INMOTION PARTS WS99193.
Fluid Pump Seal
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| BCA Fits: all 1961 Marathon engines | NS6988H | 🇺🇸 US | FrontBorg Warner trans. | View on Amazon |
| NATIONAL Fits: all 1961 Marathon engines | 6988H | 🇺🇸 US | Frontwith 3-Speed Borg Warner T12 Transmission | View on Amazon |
| SKF Fits: all 1961 Marathon engines | 19240 | 🇺🇸 US | Front | View on Amazon |
| WJB / INMOTION PARTS Fits: all 1961 Marathon engines | WS6988H | 🇺🇸 US | Frontwith 3-Speed Borg Warner T12 Transmission | View on Amazon |
This table covers the seals at the Fluid Pump. Typical signs include a wet housing, a drip after sitting, or fluid flung off a rotating shaft. Fix the surface the seal rides on. A new seal on a grooved shaft will leak again.
4 Fluid Pump Seal parts for the 1961 Checker Marathon come from 4 brands — BCA, NATIONAL, SKF and 1 other brand. Every part fits both the 3.7L 226cid L6 and the 5.2L 318cid V8.
Part numbers include BCA NS6988H, NATIONAL 6988H and SKF 19240, among others listed above.
Manual Shaft Seal
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| NATIONAL Fits: all 1961 Marathon engines | 7929S | 🇺🇸 US | with 3-Speed Borg Warner T12 Transmission | View on Amazon |
| WJB / INMOTION PARTS Fits: all 1961 Marathon engines | WS7929S | 🇺🇸 US | with 3-Speed Borg Warner T12 Transmission | View on Amazon |
This table covers the seals at the Manual Shaft. Typical signs include a wet housing, a drip after sitting, or fluid flung off a rotating shaft. Fix the surface the seal rides on. A new seal on a grooved shaft will leak again.
2 Manual Shaft Seal parts for the 1961 Checker Marathon come from 2 brands — NATIONAL and WJB / INMOTION PARTS. Every part fits both the 3.7L 226cid L6 and the 5.2L 318cid V8.
Listed part numbers: NATIONAL 7929S and WJB / INMOTION PARTS WS7929S.
O-Rings & Seals
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| SCHAEFFLER Fits: all 1961 Marathon engines | SS2611 | 🇺🇸 US | Rearwith 1.563 In Shaft | View on Amazon |
This table covers the O-rings and seals at this joint.
This group shows a single part: SCHAEFFLER SS2611.
Output Shaft Bearing
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| SKF Fits: all 1961 Marathon engines | 6307NRJ | 🇺🇸 US | Rear | View on Amazon |
This table covers the Output Shaft bearings. Typical signs include a growl that rises with speed, or play in the shaft or hub. Set preload the way the notes specify. A dry or crushed bearing fails quickly.
This group shows a single part: SKF 6307NRJ.
Output Shaft Seal
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| SKF Fits: 5.2L 318cid V8 | 15620 | 🇺🇸 US | Rear | View on Amazon |
This table covers the seals at the Output Shaft. Typical signs include a wet housing, a drip after sitting, or fluid flung off a rotating shaft. Fix the surface the seal rides on. A new seal on a grooved shaft will leak again.
One part is listed for the 1961 Checker Marathon — SKF 15620.
Repair Sleeve
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| SCHAEFFLER Fits: all 1961 Marathon engines | SR3482 | 🇺🇸 US | Rearwith 1.563 In Shaft | View on Amazon |
| SKF Fits: all 1961 Marathon engines | 99193 | 🇺🇸 US | Shaft Diameter: 1.937 In | View on Amazon |
This table covers the wear sleeves used to restore a grooved seal surface.
2 Repair Sleeve parts for the 1961 Checker Marathon come from 2 brands — SCHAEFFLER and SKF. Every part fits both the 3.7L 226cid L6 and the 5.2L 318cid V8.
Listed part numbers: SCHAEFFLER SR3482 and SKF 99193.
Shift Shaft Repair Sleeve
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| SKF Fits: all 1961 Marathon engines | 99076 | 🇺🇸 US | Shaft Diameter: 0.750 In | View on Amazon |
| TIMKEN Fits: all 1961 Marathon engines | KWK99076 | 🇺🇸 US | Kwik-Sleeve | View on Amazon |
This table covers the wear sleeves used to restore a Shift Shaft seal surface.
2 Shift Shaft Repair Sleeve parts for the 1961 Checker Marathon come from 2 brands — SKF and TIMKEN. Every part fits both the 3.7L 226cid L6 and the 5.2L 318cid V8.
Listed part numbers: SKF 99076 and TIMKEN KWK99076.
Shift Shaft Seal
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| SKF Fits: all 1961 Marathon engines | 7556 | 🇺🇸 US | View on Amazon | |
| TIMKEN Fits: all 1961 Marathon engines | 240816 | 🇺🇸 US | Material: S-Nitrile | View on Amazon |
This table covers the seals at the Shift Shaft. Typical signs include a wet housing, a drip after sitting, or fluid flung off a rotating shaft. Fix the surface the seal rides on. A new seal on a grooved shaft will leak again.
2 Shift Shaft Seal parts for the 1961 Checker Marathon come from 2 brands — SKF and TIMKEN. Every part fits both the 3.7L 226cid L6 and the 5.2L 318cid V8.
Listed part numbers: SKF 7556 and TIMKEN 240816.
Buying Automatic Transmission Parts for a 1961 Checker Marathon
On this vehicle, the automatic transmission covers the automatic gearbox and its supporting cast — filters, coolers, solenoids, mounts and torque-converter parts.
- Match the engine first. Some automatic transmission parts fit every engine; others are engine-specific. Each row shows which engine(s) it fits.
- 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: Extension Housing Seal and Fluid Pump Seal .
Frequently Asked Questions
How many automatic transmission parts fit the 1961 Checker Marathon?
Our catalog currently lists 21 automatic transmission parts for the 1961 Checker Marathon across 11 subcategories and 6 brands, covering both the 3.7L 226cid L6 and the 5.2L 318cid V8. Each part is matched to the engine(s) it fits.
Do automatic transmission parts differ between 1961 Checker Marathon engines?
Some do. 20 parts fit every engine; the other 1 is engine-specific. Each row (and the filter at the top) shows which. If you're unsure which engine you have, check the emissions label under the hood or the 8th character of your VIN.
What are the signs of automatic transmission problems on a 1961 Checker Marathon?
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 1961 Checker Marathon 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 1961 Checker Marathon?
First match the engine — each row shows which engine(s) the part fits. 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 1961 Checker Marathon
Automatic Transmission Parts for Other Checker Marathon Years
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