My trusty 5 speed with 206,000 miles is nearing its last leg.

I have never had the fifth gear nut issues. I tow 25000- 29000 pounds regularly.

What are the pros & cons of going to a 6 speed.

This truck has the CON OFE clutch & big flywheel with only 10,000 miles.

Would I be better served just to rebuild the 5 speed and go with the heavier shaft etc???

I could never ask for a more versatile vehicle!!!!

Truck specs.... 3500 4WD dually with #10 cam plate, South Bend CON OFE, Piers 3000 GSK, Boost Elbow & Pyro & Boost Gages


Opinions please.

Thanks,

Tom

 

Here is my opinion:

The NV5600 is a much longer unit with a mainshaft assembly that tends to whip the thin case around when run at high rpm's with a heavy load. There are known problems with the syncros; a mystery problem with shifter vibration that was supposed to be corrected with TSB 21-006-01, but still exists in some transmissions; and it tends to twist and crack the transfer case if it is used with an aftermarket overdrive unit in four wheel drive trucks.

These issues do not affect everybody, but do crop up with more frequency than I care for.

Couple the known 6 speed issues with the expense of the conversion, I would go for a rebuild on the NV4500 and save a ton of money and headaches. Unless you are having input shaft problems with the 5 speed, I would not even go the expense of the shaft change, as that will mean you have to change your clutch disk at the same time.

I believe there is a very valid reason that Dodge is dropping the NV5600 transmission in favor of the shorter Getrag 6 speed with dual countershafts and a stiffer case. http://www.popularmechanics.com/auto...ds/print.phtml