Borg-Warner Model 35 / 37
3-speed automatic · longitudinal · 1956–present
Also known as: t-37, t37, model 35, model 37, bw35, bw37
Borg-Warner's Model 35 and Model 37 — three-speed automatics fitted by almost every European maker that did not build its own.
⚑ Bought in by Saab, Jaguar, Volvo, Triumph, Rover and a dozen others, which is the useful fact: a Saab automatic question is a Borg-Warner question, and the marque's own material will not have it. The same gearbox under six badges is why its documentation is scattered.
Three speeds and a tall first is the character, and on a small European engine that makes for slow acceleration and an unwillingness to change down — the design rather than a fault, and a complaint readers make constantly.
It is entirely hydraulic. No electronics, nothing to interrogate, and a road-speed governor rather than a sensor: fluid condition, band adjustment and line pressure are the whole diagnosis, in that order.
Band adjustment is a real service item most modern technicians have never performed, and a slipping gear on one of these is frequently an adjustment rather than a rebuild — the same finding this catalogue records for Chrysler's A-series transaxles.
Cars fitted with this gearbox
1 generation. Only where a source names the model and the generation together — a gearbox is documented as a product far more often than as a fitment, so this list is deliberately shorter than the truth.
Saab
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Community experience
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