if i have the nv5600 tranny from 01-02 with the larger clutch and shaft...at what point do i need to upgrade to a billet shaft to keep from snapping it

i know autos have this problem but im not sure if the 6spd do...im going to have about 500-550 hp in the end with a DD clutch so the clutch isnt going to slip on me. if i use the DD and slip it at the track to build some boost for launching...will i have to worry about breaking anything in the nv5600 tranny.

PS- i cant wait to get another truck with a 12v auto...then i can get billet input and outputs and do boosted launches all day

 

I would say never.

Your input shaft should be 1 3/8ths, 10 spline. Very stout.

You don't have to worry about input shafts on the 6speeds because
1) It's VERy tough to do a boosted launch
2) You have no tq converter to brake torque and generate so much stress on the shaft.

I've never once heard of a broken input shaft on a later 5600. The early 5600s with the small clutch were much weaker.

How do you like those Fast Coolers? Do they make fluid swaps easier or tougher?

 

they work great...i have a tranny temp gauges that will only go to about 125 when running a steady 70mph on the highway for a long time...and they have a drain port on the bottom (i have my temp sender there now) so its fairly easy to drop the fluid...just jack up one side to get it to lean a bit so its all runs out the side where the port is

 

Huh? I did a couple when I had the bed off my truck (too heavy to dyno) Third gear, ~6-8psi and the rear end power hops so bad I feel like it's coming out. ~10psi and the tires go up 4th gear won't work!! That's with a whopping 3K lbs on the rear axle, too

Hard, no. For the average driver, . But since when are we "average" My spongy brake pedal makes it a lot harder than it should be I'm curious as to what my clutch looks like now...it wasn't built to handle that kind of abuse, just heavy towing. It shifted a lot nicer afterward though

I don't know of any billet input evan available, though. Peter never said anything about one when I told him I has going to the NV5600!

Chris

 

No one makes a heavy duty 1 3/8" input for the 6 speed.
They typically do not break but a couple and I mean a couple at the most have broken and one was from bad harmonics.

I know Enterprise engine does make a heavy duty mainshaft for the nv5600 because some sledpullers have broken the mains using high gears like 2nd hi range.

I have heard that there is a heavy duty output shaft but I do not have any knowledge on who makes it and if it really exists. I have heard of some output shafts breaking due to massive horsepower and a rough sledpullin track (IE Curt Haisley@Indoor pull Illinois 05).

 

So that means I should never break mine...since I can't sledpull effectivly (2wd)??

Chris

 

Das right...

 

Yes, but your 6-8psi launch is a far cry from the 18-20psi shaft-shattering launches some of the automatic guys are doing.

You made my point: it's hard to generate enough boost on a launch to hurt the 5600.

No, go a beHAAAAVE in your truck

 

thats good and puts my mind to ease...now i just need a DD and twins or a smaller single

 

I've tried a few powerbrakes launches since I got the DD in. In third I build to 10 then let off the brakes and in less than a second I'm at 45 lbs I swear I saw a billet 1 3/8 input shaft online somewhere for around $2500 I hope I'll never need one =\

 

i have done 40 psi plus launches and the stock input shaft is still there. and this is on a 8k# dually 4x4.

 

Only reason I didn't push it farther was for the clutches sake Peter told me not too, and right now I'm too broke to get it rebuilt

Chris