Borg Warner Differential

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Australian-assembled B110s and B210s used a Borg Warner rear axle assembly. These use a 'Salisbury' type differential, where the gears are embedded into the axle housing. Other B110s used the Hitachi Differential, with a removable "pumpkin" gear center-section. Also some South Africa 1200s were fitted with a BW differential. The Borg Warner 78 is a popular swap for 1200s in Australia.

* B110: Borg Warner Model 60
* B210: Borg Warner Model 68 (8-bolt cover)
* R31 Australia: Borg Warner Model 78 (9-bolt cover)

Model 60

Australian-assembled B110s used a Borg Warner Model 60 rear axle, starting with chassis numbers:

• Manual serial number 54507
• Automatic serial number 40937

This started in Late 1971.

Apparently this is the same diff that was in AMI-built Corolla KE10, but those have a 4 x 110 wheel bolt pattern.

Part Numbers

• 38300-H1000BW Carrier & Diff Assembly
• 38310-G0400BW Carrier
• 38315-G0400BW Bolt-carrier bearing

Model 68

Australian 120Y 4-dr Sedans from July 1976 were locally assembled and used a Borg Warner rear axle assembly. (BW model 68). All were 3.889 ratio. The 120Y Coupe, Wagon, and Panel Van, being fully imported into Australia, continued to use the Hitachi [Jap] rear-end in 3.9 ratio while the Van might have had a different [lower] ratio.

BW - removable back cover

Japan - welded back cover

BW68 - 10-bolt cover

BW can be identified as there is a rear cover (the diff [center] doesn't unbolt from the front of the axle housing - like a GM differential only smaller). There will be a metal tag on one of the bolts that holds the cover on. It tells you which type of Borg Warner, and also the ratio (makes life easy at the wreckers).

They say Borg Warner on the bottom.

• it will be a BW if it has a removable cover at the back of the diff
• and either a H150 or H145 if it doesnt

The BW68 is the same width as a 1200 H145 diff, but have a different input flange, so you will also need the matching 120Y-BW tailshaft.

43000-H7A05-02 ???

This is the same type of differential in the early Corollas.

Since the BW68 axle housings are a larger diameter, spring seats and U-bolts with wider spacings are used:

25-spline axles

Click each photo for more detail

adapted Bluebird Disc brakes

Borg Warner 78

Australian-built R31 came with a Borg Warner 78 diff (198 mm ring gear). The ring gear (CRP) is strong, about as strong as the H190 in the Datsun pickups.

A unique feature is the 9-bolt rear cover.

640 641 1202

Rear Disc Brakes

Swaps

BW78 can be narrowed and installed in 1200.

See R31 Swap Notes

Splines

R31 Skyline: 28-spline axles (strong)
R31 Pintara: 25-spline axles (weaker)

LSD

R31 Skyline Silhouette had 4-pinion LSD.

BW78 LSD out of a Holden an be fitted.

There are two series BW78 carrier, LSD are different for each.

Brake Upgrades

Large 300ZX rear caliper adapted

Comparison

The BW rear ends are pretty strong - meant to be stronger than the similar-size Hitachi diffs.

BW60: 6.0" ring gear (152 mm -- larger than H145)
BW68: 6.8" ring gear (173 mm -- larger than H165)
BW78: 7.8" ring gear (198 mm -- larger than H190)

BW60 (1200) vs BW68 (120Y)

BW68 (120Y) vs BW78 (R31 Australia)

Comparo: BW78 vs H165