Stupid input shaft!

C

Cnp22

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Sep 27, 2009
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I broke my third input shaft in the getrag Friday.:bang and I'm just wondering if something more is going on? And why doent anybody make a billit input for the getrag?
 
I know, it will get a built nv but I just didn't want to do all that work. Got to make a crossmember, change the adapter plate get a diffrent clutch for the billit input. Buch of crap I got to do. The getrag is a good tranny well mine is anyway, I havnt had any problems but the input shaft.
 
Cnp22 said:
I know, it will get a built nv but I just didn't want to do all that work. Got to make a crossmember, change the adapter plate get a diffrent clutch for the billit input. Buch of crap I got to do. The getrag is a good tranny well mine is anyway, I havnt had any problems but the input shaft.
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So it's a good tranny but you've broken 3 inputs?? YOur definition of good is a bit different than mine.

I've broken 1 input on my NV4500 at almost 400hp towing loads over 30K lbs GVW...Also broken 5th gear once.

Our stock service truck has broken it's NV4500 3 times now...

I wouldn't call them good, but can't say they're doing too bad either!

Chris
 
Well it's been good compaired to my old nv trucks iv shreaded all kinds of internals with my old trucks with nvs with less power. I hit the track with it every once in a while but they break on the street either in 4th or 5th gear.

Forrest Nearing said:
have you tried having them cryo'd?
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I havnt yet, have you or anyone you know tried it? The 1st that broke was stock the 2nd was used with 120,000 miles the one I just broke was new.
 
the aftermarket getrag input shafts are junk. try to find an OEM one like captain said.
 
Will I have to go to cummins to get a oem one? Now I can't find the site for cryo, can some one post a link or the name of the site.
 
When does said breakage happen? Speed shifting, clutch release/engagement, etc?

You have it over filled by 1qt yet?

Stomp can get his to hold 700+hp on STOCK input shaft size, can the NV?
 
oldestof11 said:
When does said breakage happen? Speed shifting, clutch release/engagement, etc?

You have it over filled by 1qt yet?

Stomp can get his to hold 700+hp on STOCK input shaft size, can the NV?
Click to expand...

It breaks in the middle of 4th or 5th gear right about the time the tires, i mean tire stops spinning.:lolly: I havnt over filled it I don't see that helping any thing maybe put more stress on it, sure it will run cooler but the input shaft is not in side the tranny. I havnt seen a stock nv shaft or internals for that matter hold much over 500 that's what I don't understand becuse stomp even has a duel disk and I only have a single.
 
Cnp22 said:
I broke my third input shaft in the getrag Friday.:bang and I'm just wondering if something more is going on? And why doent anybody make a billit input for the getrag?
Click to expand...
Getting the tire spin under control would be a first step, the shock of going from spinning to sudden traction loads everything, input, mainshaft, motor mounts, pinion, as I said everything.

One thing I have heard, but never really had a chance to verify, is bellousing alignment on the Getrag is said to be inconsistant.
By that I mean that the bell centerline is not in alignment with the centerline of the flywheel, which can cause slight loading in the wrong direction.
This causes a flex point that will either trash the pilot bushing, cause incorrect clutch release (disc on a bind) or even breakage of a variety of types.

As far as improving the getrag, IMO a redesigned input with a HARDENED steel race and an option of a 1-3/8" diameter shaft would be greatly beneficial.
From a shifting standpoint, a set of forged steel (even cast steel) shift forks would go a long way to cure that "did I shift it too fast and break it?" feeling.

I used to run my 340s with A-833 Mopar 4 speeds, which usually had brass forks.
I heard about the trick of using the A-833 Overdrive forks, which are steel, in the early transmission.
It made a HUGE difference in the way the tranny shifted.

Mark.
 
Mark Nixon said:
One thing I have heard, but never really had a chance to verify, is bellhousing alignment on the Getrag is said to be inconsistent.
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Hey Mark,

I've heard the same thing. Think it was Phillip over at CF.com who told me that. I've yet to check mine, but it seems like a good possibility that it's causing MY problems...

But I guess that's an unnecessary tangent. Might be worth checking out while the tranny is out, though.
 
Yeah, that guy has mentioned it, but Mysteryman, among others, has also mentioned it.

A local tranny guy mentioned it first, then I ran across Terry (Mysteryman), who went a bit more in depth about it.
I truly believe the alignment, compounded by the lube issue, has really hurt the reputation of what has since been proven, once corrected, to be a very durable and reliable light-medium duty transmission.

Admittedly, I have broken the cases, but I'm talking about grossly overloaded (27,000+ pounds) and a lot of High Rockies hill climbing to do it.

Mark.
 
I remember reading his thread on the Getrag and how the NV4500 was really just substituted for cost savings, rather than an improvement in performance/reliability.
 
Yep, but that's our automaker's for ya'.
Instead of fixing a problem, just design another and have a few more, yet different, problems.

I feel the NV4500 is only "better" because it is of GM descent, as such it is more widely recognized, thus gets more aftermarket support.
If Chevy hadn't used it, we'd be in the same boat with it, as we are with the Getrag.

Mark.
 
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Thanks mark, I was thinking the same thing with the tire spin, becuase it's spinning then all the sudden it stops it snaps on everthing and the input just happens to be the weakest link. But intell I get a locker or weld it I'll just have to hold back on the 60 mph burnouts. Iv never had problems as far as shifting mine is smooth and goes right in with out any problems. How do I check the bellhousing alingment? That seem like it could be my problem all so.
 
I'm not 100% sure how it's set-up, but checking the alignment is done with a dial indicator "somehow affixed" (this is the "not sure part") to the center of the crankshaft, and the dial indicator's probe end located on the pilot hole of the bellhousing.
You then rotate the crank and note the runout amount and it's position on the bell's pilot hole, then correct it by offset dowel pins in the bellhousing.

There are places that sell offset dowel pins to relocate the bell accordingly.

Mark.
 
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