Anyone had a driveshaft explode on the K2XX platform? The shaft on my '18 RCSB is steel. I was wondering if all models have a steel shaft or if some are equipped with aluminum. I don't want to get somebody hurt on the dyno.

 

there are a few guys in here that are pretty knowledgeable on driveshafts. These shafts are pretty long even on rcsbs, a 4x4 will be shorter but I was surprised at how long mine is on my rcsb 2wd.

 

from videos i have seen... dont run them much over 100mph for long
stock is amazingly thin

& not just k2xx platform...older ones too

guess engineers didnt think we make these race trucks hehe


eta:
i need to stop being lazy & get a new shaft made. i'd like a dyno run that can be made in 4th instead of 3rd....curious to see what diff in graph or power there possible is.

 

Yeah not real safe at speed although a RCSB is much better I'm told. I mistakenly did 110 or so passing 4 cars and a semi last year with my 14 and quickly shut it down.

 

lol i ran mine up to 113ish by the speedo the other day, my dad claimed his truck was faster, then it shut down on me.

 

All driveshafts will fail when run at or near their critical speed. This happens to translate to around 105-115 on most of these crew cab trucks. This is above the stock tire speed rating anyway. Basically no reason you should get there on a stock truck, so when you go modified and want to go faster you need to upgrade the driveshaft.

 

Anyone know the actual facts about the autotrac driveshafts and u joints? I know GM beefed them up considerably to handle shock loading of jumping in and out of 4x4 at speed and under load. I was considering a driveshaft but the fellow that was looking at it said I was wasting my money, my was fine for what I'm doing? Makes me nervous, I'm having a driveshaft loop installed while my trans is being built for added peace of mind.

 

All of the ones I have seen pop were aluminum.

The shorter the shaft the higher the critical speed though.

So regular cab short bed 4x4's will have the shortest shaft, then 2wd reg cab, then ex cab/crew then long bed ex cab/crew

That all being said I've seen videos of the aluminum shafts coming apart in even the reg cab short bed trucks at a hair over 100 mph on the dyno.



Unfortunately I have not seen anything or heard of anything about steel shafts in these trucks so I have no idea where the limit is on those. Call driveshaft specialist inc of texas. I've called many shops trying to have a conversation about critical speed and they are the only one that didn't completely blow off the conversation and go straight to trying to sell me a thicker wall drive shaft. They are the only one that made sure to address my concerns first. They also had a great price.

If I had to guess, I would guess your steel shaft will hold up better than the OE aluminum one, but at this point that's a pure guess until more info starts to come out about them, I haven't even heard steel shafts mentioned in these newer trucks, yours is the first I've heard of.

 

BTW welcome pmoore4321! Guys he is a wealth of info on L83 mods and likely much more. He's the one that has so many Youtube vids on E85 conversion, cam upgrades and a host of other truck stuff. Also he documents everything! A member of Camaro6 forum as is Choda and Parish8 to name a few...and me a few months ago. Glad to have you here so please stop by often. But it's hard to know everything. Unless you're Atomic of course

 

Is your truck autotrac?