QU10093 1992-1994 39 Tooth GM NV4500 Countershaft Front Gear

QU10093 1992-1994 39 Tooth GM NV4500 Countershaft Front Gear for 6.34:1 1st and reverse gear ratio 1992-1994 GM NV4500 5 speed manual transmissions. Your matching Main Drive Gear (Input Shaft) must have 20 teeth. QU10093 is the big front gear on your modular Countershaft and it ONLY works in 1992-1994 GM NV4500 transmissions with 20 tooth input shafts. QU10093 is driven by the input shaft, but it is also called the Countershaft Drive Gear or Countershaft 4th gear. Imported.

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Dan the Gear Man® Tech Notes:
Input Gears
Countershaft Failures
Matching Parts
NV4500 Tools
Applications

Tech Note 1: Input Gears
QU10093 is a 39 tooth, keyed, press-fit gear that fits QU10090 Countershaft. The transmissions that use this gear will be 1992-1994 GM NV4500 transmissions with 6.34:1 1st and reverse gear ratios. The matching input shaft MUST have 20 teeth (See QU10043AM). QU10093 is NOT compatible with 1992-1995 Dodge and 1995 GM 5.61:1 ratio NV4500 transmissions using 22 tooth input shafts.

Tech Note 2: Countershaft Failures
Typically, Countershaft gear tooth failures occur from one of three causes: low or improper oil, clutch pilot bearing failures (which cause misalignment of the input shaft), and excessive horsepower/torque (over 275hp/600 Lb-Ft of torque). Broken 3rd gear teeth are almost always caused by 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 3: Matching Parts
Matching Parts for QU10093 Countershaft Gear:
QU10090 Modular Countershaft
QK1129 Drive Key Kit
QU10094 32 Tooth Countershaft 3rd Gear
QU90020 NV4500 Manual Transmission Oil
TM1003 NV4500 Shop Manual
VSG1003DVD NV4500 Overhaul Video
QU10043AM 20 Tooth Input 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.

Applications
Chevy and GMC:
All with 6.34:1 Low Gear Ratio New Venture NV4500 5 Speed Manual Transmission: 1992, 1993, 1994