QU10203 6.22" Diameter 51 Tooth NV4500 Countershaft 5th Gear

QU10203 6.22" Diameter 51 Tooth NV4500 Countershaft 5th Gear Is a quality replacement 51 Tooth Countershaft 5th Gear for all Dodge and 1995-2007 GM NV4500 transmissions. QU10203 is compatible with all 5.61"1 1st gear ratio NV4500 transmissions including 1992-1993 Dodge NV4500, 1994-2005 Dodge NV4500LD, 1994-2004 Dodge NV4500HD models plus all 1995-2007 GM NV4500 Transmissions. Your matching driven mainshaft 5th gear must have 22 teeth. Imported.

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Dan the Gear Man® Tech Notes:
Fits
Tooth Failures
Special Tools
Matching Parts
Lubricants, Sealants, Threadlockers
Applications

Tech Note 1: Fits
QU10203 is a 51, 6.22" outside diameter bearing supported gear that fits on the back of NV4500 Countershafts. The transmissions that use this gear will have 5.61:1 1st gear ratio and either 5.61 (1992-1996) or 5.04:1 (1997-2007) reverse gear ratios. The matching mainshaft 5th gear MUST have 22 teeth. QU10203 Gear replaces OE QU10029 5th Gear. QU10203 is NOT compatible with 1992-1994 GM NV4500 transmissions with 6.34:1 low gear ratio.

Tech Note 2: Tooth Failures
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 misalignment (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 NV4500HD transmission is only 460 lb./ft..

Tech Note 3: Special 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 4: Matching Parts
QU10140 Sealing Cap, Main Case Countershaft Front Bearing Bore
QK1102 Lock Ring Kit
QK1110 Thrust Washer Locating Pin Set
QK1099 Synchro Strut Set
QU10304 Countershaft 5th Gear Thrustwasher
QU10039 5th Gear Sliding Clutch Ring
QU10003 5th Gear Synchro Ring
QU10202 5th Gear Clutch
QU10007 or QU10086 Mainshaft 5th Gear Dodge NV4500LD and 1995-2007 GM
QU10067 Mainshaft 5th Gear 1994-2004 Dodge NV4500HD
QU10090 Modular Countershaft
QU10078 Countershaft Assembly for 1992-1996 EXCEPT GM with 6.34 Ratio
QU10192/QU10707 1997-2007 Countershaft Assemblies
QU90020 NV4500 Manual Transmission Oil
TM1003 NV4500 Shop Manual
VSG1003DVD NV4500 Overhaul Video
Chevy & GMC Shop Manuals
Dodge & Ram Shop Manuals

Tech Note 5: Lubricants, Sealants, Threadlockers
Early production NV4500 Transmissions used an anaerobic sealant (QU90003) to seal between the main case and input bearing retainer, top cover, and rear housing. Mid-production units used anaerobic sealant just on the input retainer and RTV for everything else. Later production transmissions used black RTV Sealant (QU90006 or QU90005) for everything. Either type of sealant works fine (except the PTO covers ALWAYS should be sealed with RTV), but I prefer RTV for all components. Regardless of which sealant you use, make sure excess sealant does not block the lube access hole at the top of input retainer pilot that fits into the transmission case! Also, the threaded holes in the main case for the four retainer bolts and 12 PTO bolts are open ended, so you must use new bolts with factory applied threadlocker or apply Threadlocker (S24200) to your existing bolts to prevent oil seepage past the bolt threads. See my TM1003 NV4500 Shop Manual or VSG1003DVD NV4500 Overhaul Video for more information.

Lubricant and Chemical List for NV4500 Transmissions:
QU90020 NV4500 Manual Transmission Oil
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

Applications:
Chevy and GMC:
All with New Venture MT8 or MW3 NV4500 5 Speed Manual Transmission: 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007

Dodge and Ram:
D and W Series with Gas Engines and New Venture NV4500 5 Speed Manual Transmission: 1992, 1993 
Ram 2500, Ram 3500 with Gas V8 Engine and NV4500LD 5 Speed Manual Transmission: 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005
Ram 2500, Ram 3500 with V10 Engine and NV4500HD 5 Speed Manual Transmission: 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003
Ram 2500, Ram 3500 with Cummins Diesel and NV4500HD 5 Speed Manual Transmission: 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004