Hummer H3. Manual — part 1542

reverse is from the input shaft (100), to the countershaft (400), to the reverse idler gear (175), to
the reverse gear teeth on the 1st/2nd synchronizer sleeve (170), through the synchronizer and to
the output shaft (195). Using the 5th/reverse synchronizer avoids gear clash when shifting in
reverse. When moving the reverse shift fork forward, simultaneously the 5th shift fork (250)
moves the 5th/reverse synchronizer sleeve (254) forward. The internal splines of the synchronizer
sleeve slide on the splines of the 5th countershaft gear (450). At the same time, the synchronizer
sleeve splines are pushing against the teeth on the reverse gear synchronizer ring (276). The
action moves the reverse gear synchronizer ring (276) forward. The reverse/5th inner ring (278)
or pull ring, locking to the reverse gear synchronizer ring (276) moves forward. The reverse/5th
inner ring (278) pulls forward and tabbed lock to the reverse/5th internal ring (277) forces the
reverse internal ring (277) against the 5th gear blocking ring (256). The 5th gear blocking ring
(256) is moving at the same revolutions as the output shaft (195). The reverse internal ring (277),
tabbed to the 5th synchronizer gear (255), is revolving at the countershaft (400) speed. The
synchronizer action matches the revolutions of the countershaft (400) to output shaft (195)
revolutions, allowing the reverse idler (175) to engage without gear clashing.

SPECIAL TOOLS AND EQUIPMENT

SPECIAL TOOLS

Special Tools

Illustration

Tool Number/Description

J 6125-1B

Slide Hammer with Adapter

2007 Hummer H3

2007 TRANSMISSION Manual Transmission - Aisin AR5 - H3

J 6133-A

Bearing Race Installer

J 8001-3

Dial Indicator

J 8433

Two Jaw Puller

J 22912-01

Rear Pinion and Axle Bearing

Remover

2007 Hummer H3

2007 TRANSMISSION Manual Transmission - Aisin AR5 - H3

J 23129

Universal Seal Remover

J 26900-12

Dial Indicator

J 26900-13

2007 Hummer H3

2007 TRANSMISSION Manual Transmission - Aisin AR5 - H3

Magnetic Indicator Base

J 35616

GM-Approved Terminal Test Kit

J 36850

Transjel Lubricant

2007 Hummer H3

2007 TRANSMISSION Manual Transmission - Aisin AR5 - H3