QU10728 19 Tooth Early GM Mainshaft 5th Gear


QU10728 19 Tooth 1992-1994 GM Mainshaft 5th Gear For your low-ratio, 1992-1994 GM New Venture NV4500 Transmission. QU10728 is a  quality reproduction mainshaft 5th gear that fits in 1992-1994 GM NV4500 transmissions with 6.34:1 1st and reverse gear ratios. 31 internal spline gear fits both 4x4 and 4x2 applications.

19 Tooth Early GM Mainshaft 5th Gear
* Kits made up of multiple items may not show an inventory in-stock status but are almost always in stock!

tech note

Dan the Gear Man® Tech Note 1:
Of all the NV4500 variants, the GM 4x2 version of the New Venture NV4500 5 speed manual transmission is the most resistant to "losing fifth gear".

tech note

Dan the Gear Man® Tech Note 2:
Typically, Countershaft 5th gear tooth failures occur from one of three causes: low or improper oil, misalignment of the maishaft to countershaft, and excessive horsepower/torque (over 275hp/600 Lb-Ft of torque). Broken 5th gear teeth are almost always caused by a combination of shaft misalginment (loose bearings or defective tailhousing) and exceeding the demonstrated 600 Lb.Ft input strength limit of the NV4500.

There are claims that cryogenically treating NV4500 gears will increase gear strength as much as 30%. Unfortunately, there does not seem to be any peer-reviewed documentary evidence to support those claims. Cryogenically treating gears is primarily a cold-hardening process that changes the molecular structure of steel to decrease wear while retaining or increasing hardness. If properly done, it is probable the cryogenic treatment process does slightly increase the impact and fatigue resistance of NV4500 gears, but not enough to significantly increase the ability of an NV4500 transmission to reliably handle more than 600 Lb.-Ft. of input torque especially considering the maximum factory torque rating of the GM NV4500 transmission is only 450 Lb.-Ft..

tech note

Dan the Gear Man® Tech Note 3:
Need Torque Specs or Rebuild procedures? Order my 116 page, full color illustrated NV4500 Rebuild Manual.

You will need some special tools to correctly service your NV4500 Transmission. The chart below lists our current NV4500 Special Tools for popular models.


Component 23 Spline
Dodge 4x4
29 Spline
Dodge 4x4
30 Spline
Dodge 4x2
31 Spline
Dodge 4x2
32 Spline
GM 4x4
35 Spline
GM 4x2
Mainshaft Nut QT2002 QT2001
QT2002 QT2001
1-1/2" Hex
Mainshaft Holding NLA QT2000 NLA QT2011 N/A N/A
5th Gear Nut
Torx® Cross Bolt
N/A QT9205 N/A QT9205 N/A N/A
Output Seal Installer N/A QT1801 N/A QT2058
Not Used Not Used
Tailshaft Bushing Remover and Installer Not Used Not Used Not Used QT2044 Not Used Not Used


Front Bearing Cup Installer
QT1802 Use with QT1101 or QT1119 Driver Handle. Also can use flat side to install Dodge 4x4 Rear Output Seal
Countershaft Front Bearing Installer QT2004 Can also use to press 3-4 Synchro Hub on original equipment mainshafts
Input Bearing & Countershaft Rear Bearing Installer QT2005 Can also use to install Input Seal
Input Bearing Cup Installer QT1801 Use with QT1100, QT1101, QT1116, or QT1119 Driver Handle.
Countershaft Support QT2006 Use to support front of countersahft when installing countershaft rear bearing
1-2 Synchronizer Support QT2008 Use to support 1-2 synchronizer hub during synchronizer assembly
10mm 1/2" Drive 12 Point Socket QT1020 USA Made Impact Socket for Factory Tailshaft Housing Bolts
Long Shank Punch for Shift Lug QT9300 3/16" x 8" Shank for 5th Gear Shift Lug Roll Pin
tech note

Dan the Gear Man® Tech Note 4:
QU10728 has 19 teeth and 31 internal splines and it is specific to 1992-1994 GM NV4500 tranmissions with 6.34:1 1st and reverse gear ratios. The matching countershaft 5th gear will be just under 6-1/2" in diameter. QU10728 will NOT fit any other NV4500 transmission.

tech note

Dan the Gear Man® Tech Note 5:
Matching Parts for QU10728 1992-1994 GM NV4500 Mainshaft Fifth Gear:
QU10729 51 Tooth x 6.46" Diameter Countershaft 5th Gear
QU10098 32 Spline 4x4 Output Shaft for GM
QU10719 35 Spline 4x2 Output Shaft for GM C-Trucks
QU10212 35 Spline 4x2 Output Shaft for 1992-2002 GM C3500HD
QU10236 32 Spline 4x2 Output Shaft for GM P-Trucks
QU10719 GM 4x2 Transmission Mainshaft Spacer/Tone Ring
QK1093 Original Equipment Mainshaft Nut Set for GM 4x4
QU10097 Aftermarket Nut Set with Set Screws for GM 4x4
QT2002 Mainshaft Nut Wrench for GM 4x4 models without Vibration Dampener
QT2028 Mainshaft Nut Socket for GM 4x4 models with Vibration Dampener


Chevy and GMC:
1992-1994 All with MT8 New Venture NV4500 5 Speed Manual Transmission