QU10731 NV4500 Heavy-Duty 1 ¼ "-10 spline Input Shaft for 1996-2002 GM

QU10731 1996-2002 GM NV4500 Heavy-Duty 1 ¼ "-10 spline Input Shaft for 1996-2002 Chevy and GMC C3500HD Cab and Chassis truck. These rugged Main Drive Gears (Input Shafts) were used in GM C3500HD commercial applications, but except for the shaft diameter they are identical to the smaller QU10059 1-1/8" shaft used in 1996-up regular trucks. Just change your clutch hub and clutch release assembly to upgrade your transmission with one of these beefy shafts. Genuine New Venture Main Drive Gear includes Timken® High-Performance Input Bearing. USA Made. *Limited to Supply On Hand!

Need More Info? Use the handy Links below to access over 40 years of Dan's product and vehicle specific Tech Notes to easily get the information you need for your vehicle's repair, maintenance, or upgrade project!

Dan the Gear Man® Tech Notes:
Dims
Input shaft failures
Torque Rating
Three Bearings
Tools
Matching Parts
Matching NV4500 Synchronizer Parts
Applications

Tech Note 1: Dims:
QU10731 is a 22 tooth 1-1/4" x 10 spline genuine New Venture input shaft. The matching Countershaft Gear must have 38 teeth. The approximate overall length is 8-15/16". The stick-out length from the front of the transmission case is approximately 6-9/16". The tip for the pilot bearing is 0.59". Combined Input Shaft and Mainshaft End-Play should be set at 0.002"-0.006". QU10731 is specific to 1996-2002 GM C3500HD trucks but it will also work in any 1996-2007 GM NV4500 transmissions with the 5:61:1 first gear ratio if you have the correct clutch release assembly and clutch hub. It is NOT compatible with 1992-1994 GM transmissions with the 6.34:1 1st and reverse gear ratios!

Tech Note 2: Input shaft failures:
The majority of NV4500 Input shaft failures are caused by one or more of the following:
#1. Failed clutch pilot bearing or bushing which chews up the input tip and can cause gear tooth breakage from misalignment between the engine and transmission.
#2. Running the transmission low on oil or with the wrong oil.
#3. Excessive horsepower which can cause either tooth breakage or the shaft to twist off.
#4. Bellhousing Index Hole off center and/or Bellhousing to block alignment pin(s) missing. A gasoline engine bellhousing that has a bellhousing to transmission index hole that is more than 0.010" off center from the crankshaft centerline should be replaced.

Tech Note 3: Torque Rating:
The GM New Venture NV4500 transmission was factory rated at 450 LB.-FT. of input torque. The infamous NV4500 fifth gear issue which plagues Dodge Diesel powered trucks is not a significant issue with any GM 4x2 model or 4x4 gasoline powered applications but it is something that does sometimes affect GM 4x4 diesel models. NV4500 performance and longevity is excellent with stock gasoline engines and good with diesel engines.

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 NV4500HD transmission is only 460 Lb.-Ft..

Tech Note 4: Three Bearings:
The New Venture NV4500 Input Shaft is designed to use three bearings. The input shaft is supported by a pressed-on Timken® high-performance Tapered Bearing Set. The back of the input shaft is bored for straight, caged roller bearing. The back face of the input shaft is ground flat for contacting the mainshaft to input thrust bearing. Another design feature of NV4500 input shafts is the 4th gear clutch ring is not an integral part of the input shaft, instead it is a slip fit to splines machined behind the input gear teeth. Incidentally, with the NV4500, 4th "gear" is simply a direct connection between the input shaft and output shaft with no power transfer through the countershaft.

Tech Note 5: 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 6: Matching Parts:
QU10049 or QU10702 4th Gear Clutch
QU10704 1996-2007 GM Input Bearing Retainer
QU10124 Timken® High Performance Input Bearing
QU10125 Timken® High Performance Input Bearing Cup
QU10133 NV4500 Input Pocket Bearing
QU10134 NV4500 Input Thrust Bearing
QU10126 Input Seal
QA10009 Complete Mainshaft Shim Kit
QU10009B Basic Mainshaft Shim Kit
QK1010 Complete Small Parts Kit
QU10221 Basic Small Parts Kit
QU10078 One Piece Countershaft Assembly for 1995-1996 5.61 Reverse Gear Ratio
QU10192 and QU10707 Countershaft Assembly for 1997-up 5.04:1 Reverse Gear Ratio
QU90020 NV4500 Manual Transmission Oil
TM1003 NV4500 Shop Manual
VSG1003DVD NV4500 Overhaul Video

Tech Note 7: Matching NV4500 Synchronizer Parts:

Applications:
Chevy and GMC:
C3500HD Trucks with New Venture NV4500 5 Speed Manual Transmission: 1996, 1997, 1998, 1999, 2000, 2001, 2002
C4500 Trucks with 1-1/4" 10 Spline input shaft