MACK T309, T309L and T309LR Shifting Instructions

Caution

Make sur e air essur e least psi and unit operating temperatur e befor e making range shifts. Always start This also applies dynamometer testing. When the truck stationary , NOT shift into range and then start moving the damage the synchr onizer may r esult.

The T309 unit a range - shifted transmission which has eight forward highway speeds plus extra speed gear the range. This transmission features a and auxiliary compound section controlled air - shift range selector located the shift lever . The compound section equipped with a synchronizer facilitate - range shifting.

The range provides five low

Never attempt move the vehicle from a stopped position any gear higher than second gear Depending the grade road may necessary start speed gear first - second Note that speed gear was designed for f - highway use such material spreading heavy load/steep grade

The range has four forward gears that can shifted the standard manner . Remember , however , double - clutch when moving down through these gears.

REVERSE can used range only

Upshift — Under normal highway conditions, with shift lever NEUTRAL, flip air - shift range selector range, then shift the transmission into first gear (see shift pattern). Shift through second, third and fourth, double - clutching between gears. When maximum RPM reached fourth gear , flip air - shift range selector range (preselect) and then move shift lever through

NEUTRAL fifth gear . the shift lever passes through NEUTRAL, will put the transmission range. Now continue double - clutching through sixth, seventh and eighth gears.

Caution

NOT move the air - shift range selector while moving when the truck stationary , NOT shift into range and then start moving the Damage the synchr onizer may r

Downshift T o downshift the shift from eighth sixth and fifth (HI double - clutching between While still fifth gear , flip the air - shift range selector range then shift through NEUTRAL fourth gear you shift through the range shift will Move the shift lever second and double - clutching between

T309 and T309L Reverse — Reverse can used range only .

T309LR Reverse Reverse can used and range.

T o m a k e a r a n g e s h i f t i n r e v e r s e , bring the truck a complete Flip the range selector the range desired Move the shift lever out reverse through and then back into reverse the lever moves through the range shift will

Caution

T o avoid transmission NOT change range while moving https://www.truck-manuals.net/

C0029346