Engine/Transmission (1994 - 1998) New to this

[Diane Manskie]

Early 1998 Dodge 2500 5 speed manual transmission lost 5th gear, looking for suggestions on fixes or possible conversions to 6 speed manual. Thanks

 

[Matt42]

This is a common problem with the NV-4500 5 speed transmissions. Basically, the nut holding the 5th gear in place loosens up and falls off into the transmission case. That's in most of the cases. In a small percentage, it falls into something expensive and completely ruins the transmission. The problem is a design shortcut. Only half of the bore of the gear (and the corresponding part of the shaft) is splined. The other half is just a press fit.

Getting a rebuilt transmission with the retrofit 5th gear shaft and gear that are both fully splined, and with a better nut. There are variations. The shaft, gear and nut are available separately and can be used to replace just those parts into an otherwise good transmission. I believe that Standard Transmission in Ft. Worth is the site-recognized expert on this matter. Both of these otions are going to be a lot less expensive than a 6th gear retrofit. (I certainly appreciate the desire to go to a 6 speed; every time I have to shift from 3rd to 4th on an upgrade.)

This has not ever happened to me, but it has to people I know. I seldom use 5th gear, and when I do, I use 5th gear at a high enough RPM to prevent the high-torque banging on the assembly that'll loosen the nut.

 

[MLee]

First off the nut does not drop off into the bottom of the trans, causing damage. It stays on the main shaft, the gear backs off and is not usable. There are other ways to do the repair. Do a search for the 5th gear repair here on the forum. There is a firm that has a fix for this, fifthgearrepair.com/nv4500repair.html I think this is there web site. Good luck with your problem.

 

[Diane Manskie]

Thank you for your response & suggestion

 

[Diane Manskie]

thank you for your input.

 

[Missouri Mule]

if your not loaded don't shift into 5th until 50 mph. I your loaded or pulling a load don't shift until your going 60 mph. When I got Mule I loaded the bed up and a small utility trailer (3500 gvwr). 351,000 miles no problem with 5th gear nut. Of course now a days I don't load Mule down as much. If have a decent order I use Moose.