Engine/Transmission (1994 - 1998) 5sp vs 6sp

[EWalshak]

Do 6sp trans have the same challenge with the 5th gear nut that the 5sp trannys do? Im planning on buying a 2nd gen in the near future and want to know what major challenges to avoid. Thanks in advance for any help

 

[CumminsPower98]

The NV5600 does not have a 5th gear nut but instead a reverse gear nut but I have not heard of any problems from this. Of course 5th in a 6 speed is direct anyway. I have abused (lower than optimal RPMs while poring the power on when loaded) my 6th gear transporting RVs and so far so good. I have put 291k on this trany since the conversion from the OE NV4500. The reason I was abusing it some is that I had 265/75/16 tires with a 3. 54 rear so this put me in a less than ideal range for heavy loads at some speeds.

 

[wcjp]

I think the 99's had the same size input shaft as the NV4500.

 

[Vaughn MacKenzie]

Yes '99 and 2000 trucks equipped with the 6-speed have the same size input shaft as the 5-speed. Bigger shaft came with the 2001 model.