QU10073 NVG NV4500 39 Tooth Non-Synchronized Reverse Gear

QU10073 39 Tooth Non-Synchronized Reverse Gear is a replacement part for 1992 to 1996 GM NV4500 transmissions. Your matching Reverse Idler Gear will be about 2.75" wide (See QU10033).

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Dan the Gear Man® Tech Notes:
Fits Non-Synchronized Transmissions
Early and Late Reverse Gears
Reverse Gear Failures
NV4500 Tools
Conversion Chart
Matching Parts
Applications

Tech Note 1: Fits Non-Synchonized Transmissions
QU10073 fits 1992-1996 GM New Venture NV4500 Transmissions without synchronized reverse gear. You can upgrade your 1992-1996 GM NV4500 transmission to have a synchronized reverse gear by replacing your original reverse gear parts with the following parts:
QU10171 39 Tooth Synchronized Mainshaft Reverse Gear
QU10710 or QU10204 Synchronized Reverse Gear Clutch
QU10003 Reverse Synchronizer Ring
QK1099 Synchro Strut Kit

Tech Note 2: Early and Late Reverse Gears
Early (1992-1996) and Late (1997-2007) NV4500 Mainshaft Reverse Gears are not interchangeable. When first introduced, the NV4500 Transmission had a dual-plane reverse where the power transfer path from the counter shaft to the mainshaft reverse gear is offset. The front half of the 2-3/4" long reverse idler gear engages the countershaft, while the rear half drives the mainshaft reverse gear. Since there are no teeth on the counter shaft below the mainshaft reverse gear, that gear can be larger diameter and have more teeth (39). The 1992-1996 transmissions have a 6.34:1 reverse for 1992-1994 GM and 5.61:1 reverse for all Dodge and 1996 GM.

Effective with the 1997 model year, New Venture NV4500's use a single-plane reverse where the power transfer path from the countershaft to the mainshaft is inline. The full working width of the narrow, 1-1/2" wide reverse idler gear is inline with both the countershaft gear teeth and mainshaft reverse gear teeth. Since the countershaft drive teeth are now located directly under the mainshaft reverse gear, the mainshaft reverse gear diameter had to be reduced to the point it now has only 35 teeth. Less teeth means less gear reduction. All 1997 model year and newer NV4500 transmissions have a 5.04:1 Reverse.

The difference in the transmission case reverse idler gear pocket and mounting boss for the single and dual plan reverse means the countershaft, mainshaft reverse gear, reverse idler gear, and reverse idler shaft are NOT interchangeable between early and late cases.

Tech Note 3: Reverse Gear Failures
Reverse Gear tooth breakage is pretty rare with the NV4500. The most common problem is wear on the rear thrust face which is almost always caused by a loose mainshaft fifth gear and/or lubrication issues (dirty or incorrect oil). In advanced cases, the reverse gear needle bearing will fail and weld itself to the shaft or gear.

Tech Note 4: NV4500 Tools
Need Torque Specs or Rebuild procedures? Order my 116 page, full color illustrated TM1003 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.

Tech Note 5: Conversion Chart
NV4500 Transmissions are frequently used for conversion applications. The Table below lists the most popular rear output applications and their associated parts.

 *Electronic, Screw-In Speedometer Sensor
**22 Tooth Mainshaft 5th Gears listed for 1992-2005 Dodge and 1995-2007 GM with 5.61:1 1st gear ratio. 1992-1994 GM with 6.34:1 first gear ratio use 19 Tooth QU10728 Gear. QU10728 is NOT compatible with Dodge 29 and 31 Spline Output Shafts.

Tech Note 6: Matching Parts
Matching Parts for QU10073 39T Non-Synchronized Reverse Gear
QU10205 Non-Synchronized Reverse Gear Clutch
QU10039 Sliding Ring or Sleeve, Reverse Gear Lockup
QU10058 Reverse Gear Bearing
QK1098 Teflon Bearing Spacer Kit
QU10078 Countershaft 1995-1996 with 5.61:1 Reverse
QU10090 Countershaft 1992-1994 with 6.34:1 Reverse
Mainshafts: See Tech Note 5
QU90003 Anaerobic Sealant
QU90006 3.35 oz Ultra Black RTV Sealant
QU90005 0.5 oz Ultra Black RTV Sealant
S24200 6ml Medium Strength Blue Threadlocker
S9978 1 gram Medium Strength Blue Threadlocker
S9979 1 gram High Strength Red Threadlocker
S24026 High Temperature Threadlocker for Mainshaft Nut
QU90020 NV4500 Manual Transmission Oil
TM1003 NV4500 Shop Manual
V1003DVD NV4500 Overhaul Video
QT2002 Mainshaft Nut Wrench GM 4x4 w/o Vibration Dampener
QT2028 Mainshaft Nut Wrench GM 4x4 with Vibration Dampener

Applications
Chevy and GMC:
C1500, K1500, C2500, K2500, C3500, C3500HD, K3500 with NV4500 5 Speed: 1992, 1993, 1994, 1995, 1996