Has anyone here broke their stock 80 input shaft. i am upgrading the hub and the main shaft while its down , but on the fence on the input shaft upgrade. Seems overkill now, but we all know how quickly things snowball.
Thanks

 

They are more prone to break if you lock your converter at WO. On that note I have a 300m billet one made by CK performance.

 

I also run a Billet input. From what I've seen in my search for the right built unit it is the second part that goes Billet behind the fwd clutch hub.

I havent seen much on here first hand of people breaking them, but if you are upgrading the main shaft, why not the input shaft as well?

 

From what I've read the input shaft is reliable up to ~600rwhp, above that it becomes a gamble. Not many people seem to upgrade the main shaft, it's also not a common upgrade in sponsors' built units.

 

Didn't that happen to parish back in the day?

 

I upgraded mine to handle wot lockup...otherwise I wouldn't worry about it.

 

Well, I just bought the Circle D triple disk so I could lock up at wot if need be and for dyno pulls . I guess I will pull the trigger on this too. Thanks for the replies guys.

 

Do it without a question. The stock input shaft, per Jake's, is questionable above 750 crank hp. Some live well above that power and others don't. But I'd rather just do it once and be done with it. Also, don't assume all billet parts are necessarily stronger than stock, so choose your manufacturer wisely.

 

If your gonna get one get one from CK performance.

When i built my tranny i did not put one in because honestly i did not think the tranny was gonna work and i would be sending it out to get fixed. That was 2 years ago.

 

I broke my stock input shaft on a wot 2-3 shift with an unlocked converter. It was replaced with a 300m input. Then about a year after that I stripped the splines out of my overdrive planetary and ruined that shaft. So I had to buy another 300m. I'm not sure if the splines were weakened from the stock shaft breaking.

I wish I would have done the billet input on the first build.