L4N71B Swap

(Difference between revisions)

Revision as of 00:32, 20 April 2009

A 4-speed JATCO L4N71 was made during the 1980s. The top gear is an overdrive ratio, for reduced revs at highway speeds. It also has a lockup system (3rd and fourth gears are direct) for fuel-economy approaching that of a manual transmission.

Overview

Will it fit into an automatic-bodied Datsun 1200? Unknown -- try it and let us know.

Sources

The L4N71B 4-speed automatic came in Maximas and 200SX (silvia) models, as well as in Datsun pickups and Mazdas.

US Models

• Nissan Maxima 1983
• Nissan Pathfinder 1986-1989
• Nissan Van 1987-1989 (the 'rare as' USA Vanette)
• Mazda 929 1988-1990
• Mazda B2000/B2600 1987-1991
• Mazda Miata 1991-up
• Mazda RX7 1984-1988

Has two drawing of 4N71B vs 3N71B: http://forums.hybridz.org/showthread.php?t=130117
Looks like six inches of length added in the middle.

Comparo of 3-speed to 4-speed

• 4-speed is bigger around at the back, probably requires tunnel mods
• New rear engine crossmember (gearbox crossmember) will need to be fabricated
• Wiring changes are needed
• Swap converter housing with an A-series one
• Stall speeds vary, so swapping converters may be needed to find one that suits the small engine

Approximate Junkyard Costs:

• L4N71B 4-speed OD transmission from Pick-N-Pull: $130
• Flex plate including crank shaft spacers: $20
• Auto shift lever from early Datsun: $18
• Kickdown switch and mounting bracket from early Datsun: $3.50
• Automatic-size Brake pedal: $3
• Maintainence items (filter, seals, modulator): $32
• Hard fluid lines from B310: $9
• Flexible Fluid hoses: $10
• Radiator with auto-trans coolor lines: ?
• Driveshaft shortened, rebuilt, balanced: $165
  • length is 2.7 cm (about one inch) longer
• New rear transmission mount: $25
• Hardware (bolts, nuts, metal spacers): $15
• L3N71A/L3N71B converter housing for A-series engine
  • Will this fit on the L4N71B?

references:

• Zcar.com
• Ratsun