1958 Checker A8 Automatic Transmission Parts

Engine:
3.7L 226cid L6

The 1958 Checker A8 has 31 automatic transmission parts with verified fitment on this page — 10 part types and 9 brands, covering the 3.7L 226cid L6 engine. Each part includes a manufacturer part number and application notes.

On the 1958 Checker A8, 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 (8 parts), Fluid Pump Seal (7 parts) and Fluid Pan Gasket (3 parts). The other 7 part types cover the remaining 13 parts.

Extension Housing Seal

Brand Part Number Markets Notes Buy
NATIONAL Popular 7300S
🇺🇸 US
2 speed trans.Borg Warner trans.
Fitment notes — NATIONAL 7300S
2 speed trans.Borg Warner trans.Long Boot Style1.250 IN Width
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WJB / INMOTION PARTS Popular WS7300S
🇺🇸 US
2 speed trans.Borg Warner trans.
Fitment notes — WJB / INMOTION PARTS WS7300S
2 speed trans.Borg Warner trans.Long Boot Style
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BCA NS473234
🇺🇸 US
Trans. code T12
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NATIONAL 473234
🇺🇸 US
Trans. code T12Borg Warner trans.
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NATIONAL 5203
🇺🇸 US
Includes Bushing
Fitment notes — NATIONAL 5203
Includes Bushing
2 speed trans.Borg Warner trans.
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SCHAEFFLER SS2737
🇺🇸 US
with 1.685 In Shaft
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WJB / INMOTION PARTS WS473234
🇺🇸 US
3 speed trans.Borg Warner trans.
Fitment notes — WJB / INMOTION PARTS WS473234
3 speed trans.Borg Warner trans.T12 Transmission
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WJB / INMOTION PARTS WS5203
🇺🇸 US
2 speed trans.Borg Warner trans.
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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.

Fluid Pan Gasket

Brand Part Number Markets Notes Buy
FEL-PRO TOS18106
🇺🇸 US
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MAHLE / CLEVITE W38987
🇺🇸 US
Cork-RubberAutomatic Transmission Oil Pan Gasket
Fitment notes — MAHLE / CLEVITE W38987
Cork-RubberAutomatic Transmission Oil Pan Gasket
Borg Warner, Cruise-O-Matic ( LD, MD), Flash-O-Matic, Merc-O-Matic, 3-speed Transmissions with 14 Bolt Holes
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VICTOR REINZ 711496800
🇺🇸 US
14 Bolt
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This table covers the gaskets that seal the Fluid Pan. 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.

Fluid Pump Repair Sleeve

Brand Part Number Markets Notes Buy
NATIONAL 99199
🇺🇸 US
2 speed trans.Borg Warner trans.
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WJB / INMOTION PARTS WS99199
🇺🇸 US
Shaft Maximum Diameter (In): 2.0030000000000001 In
Fitment notes — WJB / INMOTION PARTS WS99199
Shaft Maximum Diameter (In): 2.0030000000000001 In
Front2 speed trans.Borg Warner trans.
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WJB / INMOTION PARTS WS99193
🇺🇸 US
Front3 speed trans.
Fitment notes — WJB / INMOTION PARTS WS99193
Front3 speed trans.Borg Warner trans.T12 Transmission
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This table covers the precision wear sleeves used to restore a transmission pump seal surface.

Fluid Pump Seal

Brand Part Number Markets Notes Buy
NATIONAL Popular 331107N
🇺🇸 US
Front2 speed trans.
Fitment notes — NATIONAL 331107N
Front2 speed trans.Borg Warner trans.
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WJB / INMOTION PARTS Popular WS331107N
🇺🇸 US
Front2 speed trans.
Fitment notes — WJB / INMOTION PARTS WS331107N
Front2 speed trans.Borg Warner trans.
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BCA NS331107N
🇺🇸 US
Front2 speed trans.
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BCA NS6988H
🇺🇸 US
FrontTrans. code T12
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NATIONAL 6988H
🇺🇸 US
FrontTrans. code T12
Fitment notes — NATIONAL 6988H
FrontTrans. code T12Borg Warner trans.
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SKF 21098
🇺🇸 US
Front
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WJB / INMOTION PARTS WS6988H
🇺🇸 US
Front3 speed trans.
Fitment notes — WJB / INMOTION PARTS WS6988H
Front3 speed trans.Borg Warner trans.T12 Transmission
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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.

Manual Shaft Seal

Brand Part Number Markets Notes Buy
NATIONAL 7929S
🇺🇸 US
Trans. code T12Borg Warner trans.
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WJB / INMOTION PARTS WS7929S
🇺🇸 US
3 speed trans.Borg Warner trans.
Fitment notes — WJB / INMOTION PARTS WS7929S
3 speed trans.Borg Warner trans.T12 Transmission
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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.

Output Shaft Seal

Brand Part Number Markets Notes Buy
ACDELCO 7300S
🇺🇸 US 🇨🇦 CA
Gold
Fitment notes — ACDELCO 7300S
Gold
2 speed trans.Booted (Long)1.685" Shaft1.25 IN Width
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SCHAEFFLER SS2723
🇺🇸 US
2 speed trans.Booted (Long)
Fitment notes — SCHAEFFLER SS2723
2 speed trans.Booted (Long)33.24 mm Width63.627 mm Outside Diameter
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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.

Repair Sleeve

Brand Part Number Markets Notes Buy
SCHAEFFLER SR3482
🇺🇸 US
RearA8B
Fitment notes — SCHAEFFLER SR3482
RearA8Bwith 1.563 In Shaft
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SKF 99212
🇺🇸 US
Shaft Diameter: 2.125 In
Fitment notes — SKF 99212
Shaft Diameter: 2.125 In
Front
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This table covers the wear sleeves used to restore a grooved seal surface.

Shift Shaft Seal

Brand Part Number Markets Notes Buy
SCHAEFFLER SS3644
🇺🇸 US
Trans. code T12with 0.750 In Shaft
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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.

Torque Converter Repair Sleeve

Brand Part Number Markets Notes Buy
SCHAEFFLER SR3509
🇺🇸 US
Trans. code T12with 1.938 In Shaft
Fitment notes — SCHAEFFLER SR3509
Trans. code T12with 1.938 In Shaft17.48 mm Widthwith Dual Lip
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SCHAEFFLER SR3511
🇺🇸 US
2 speed trans.with 2.00 In Shaft
Fitment notes — SCHAEFFLER SR3511
2 speed trans.with 2.00 In Shaft0.375 In Width
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This table covers the wear sleeves used to restore a Torque Converter seal surface.

Torque Converter Shaft Seal

Brand Part Number Markets Notes Buy
SCHAEFFLER SS3033
🇺🇸 US
2 speed trans.2.75" O.D. X 0.38" Width
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This table covers the seals at the Torque Converter 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.

Buying Automatic Transmission Parts for a 1958 Checker A8

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 3.7L 226cid L6 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: Extension Housing Seal and Fluid Pump Seal .

Frequently Asked Questions

How many automatic transmission parts fit the 1958 Checker A8?

Our catalog currently lists 31 automatic transmission parts for the 1958 Checker A8 across 10 subcategories and 9 brands, covering the 3.7L 226cid L6 engine. Each part is matched to the engine(s) it fits.

What are the signs of automatic transmission problems on a 1958 Checker A8?

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 1958 Checker A8 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 1958 Checker A8?

Every part on this page is matched to the 3.7L 226cid L6 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 1958 Checker A8

Automatic Transmission Parts for Other Checker A8 Years

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Manufacturer names, model designations and part numbers are used for identification and fitment reference only. AutoFactsDB is an independent catalog and is not affiliated with, endorsed by, or sponsored by any vehicle manufacturer displayed on this page.