1990 350 dodge cummins dually

[goatchin]

do you know what the problem was with the tranny? gears stickin and not coming out of gear?

 

[mdavlee]

The usual problem is 5th gear nut backing off and leaving you without 5th gear.

 

[mckeetree]

do you know what the problem was with the tranny? gears stickin and not coming out of gear?

No what happened was it got hard to get in fifth gear then fifth gear went out completely.

 

[mdavlee]

You can put an upgraded 5th gear nut and a fully splined mainshaft for them to fix that problem. That will make it hard to get into or out of 5th. Quad 4x4 has all the parts for them.

 

[goatchin]

figured-same here with our '89 with the Getrag tranny. We've been runnin her without 5th for atleast 15 years lol. My dad and grandfather used to use it to haul show cows to shows-usually 11-15 in the trailer, roughly 1500lbs a piece so it adds up plus this is back when cattle trailers were metal and not alum. when i started driving it mom and dad said my speed limit was 55mph. they werent jokin either because thats all it will do.


From the reading i've done it seems that the 5th gear nut problems in the nv4500's usually start occuring when the trucks are turned up for performance or are ran hard while in 5th gear. or is it just going to happen over time?

Mdavlee-I've seen after market nut and mainshaft kits-when you say its hard to get it to go into and out of 5th, is this still after the kit??

 

[Bearcreek]

I put the fully splined mainshaft and aftermarket nut in mine and it shifts smooth as silk.

 

[goatchin]

Sounds good


If ya dont mind me asking, do you use your truck for just driving and light hauling, or do you haul heavy loads and/or have the engine turned up? I'm trying to figure out if the problems are coming from regular use or heavy hauling, performance use.

 

[mdavlee]

I was refering to before the mainshaft upgrade. Most of the problems are related to lugging the engine down in 5th. The vibration is rough on the transmission. I tried not to drive in 5th below 1800 for more than a few seconds. The added power doesn't seem to have a bearing on 5th gear coming loose or not. I've had 3 trucks with the nv4500 and none of them had 5th gear problems and all were atleast 400hp, two were close to 500. I never had a 5th gear problem in a combined 100k. I towed heavy with them probably as much as 28k and did it at 450hp.

 

[goatchin]

good thats what i like to hear

just curious-what kind of upgrades did you do to increase the hp? turn up pump and injectors, free flow intake, free flow exaust, etc?