Help: Cognito lift, Need Beefy front Cardan shaft

[TowU4Free]

As most of you know who run this kit the front driveshaft, although it looks fine. .vibrates like hell. At least mine does, Who is making a BEEFY Double Cardan shaft for these? Cognitos are known to break as i have read personally about 15 failures just with one google click. I want something that will hold up to 20lb boosted launches, 700hp and etc. Might sound like im asking for a lot here but the stock shaft was just fine when the truck wasnt lifted. Whole purpose of this lift was to not have to lower the torsion bars anymore at the track (call me lazy)

 

[mike diesel]

I posted a thread about this. There was some good recommendations in there for shops to build stout front shafts.

Do you still have your stock front driveline? Throw it in and see if it vibrates. You may get lucky and it may work just fine for you.

 

[TowU4Free]

Mike, thanks for the reply, im still running the stock front shaft as she took her maiden voyage last night and im going on vacation tomorrow and will be driving on the beach! It seems to growl and vibrate with just a touch of throttle and just letting off with the stock shaft

 

[mike diesel]

Mike, thanks for the reply, im still running the stock front shaft as she took her maiden voyage last night and im going on vacation tomorrow and will be driving on the beach! It seems to growl and vibrate with just a touch of throttle and just letting off with the stock shaft

Ok, I misunderstood what you were saying in the original post. I thought you were saying the new double Cardone shaft was the one that was vibrating.

 

[TowU4Free]

I read it again and noticed it could be confusing, I wont even waste the money on a Cognito shaft after all the stuff i have read but DAMN this thing sounds horrible in 4x4 right now

 

[mike diesel]

I'd steer clear of any 4x4 usage until you get it figured out. You'll be picking the transfer case up off the road with continued use.

 

[TowU4Free]

Yea true, vibrations aren't good. I feel comfortable driving on the beach though seeing as it's about 15 mph max. I know guys run them like this anyway just not something I want to live with

 

[Chevy1925]

in mikes thread, it was posted that you wont be able to fit a larger DC end to take our HP due to clearance between the trans and shaft. the strongest option is a stock shaft or put a ford 271/3 case in so you have more room to run the larger DC end

 

[TowU4Free]

Damnit!.. Its always something. The vibrations im getting with this thing in 4x4 seem unsafe at drag racing speeds. Are their ANY other options?

 

[Chevy1925]

figure out how to redesign the front drop crossmember of your cognito kit to make the pinion angle point down more. putting the pinion angle at the same angle as the driveshaft on a single ended u-joint drive shaft is what is causing the vib. on these type shafts, the t-case output and pinion angle need to be at or close to the same angle as each other to allow the u-joints to quit binding and creating the vib

 

[TowU4Free]

Hmm, Is the cognito the only one with this issue? Tuff country?

 

[Chevy1925]

they are all this way.

 

[TowU4Free]

Just talked to AL at the driveshaft shop in Ny a few weeks out but hopefully he can get me setup with his custom larger cv shaft prototype thing

 

[TQMONSTR]

What does everybody else with a lift do for the front drive shaft? I'm thinking about removing my 8'' Fabtech and going with a 4''. We have long cold winters in Manitoba and I need to be able to drive 60mph in 4x4. Most of the lifts I've looked at don't mention anything about the front drive shaft (other than Cognito)

 

[Chevy1925]

I run the stock one and when I lived in the snow, I stayed below 45mph when the vibration starts in mine. If I needed to go faster, conditions were well enough for 2wd

 

[RPM Motorsports]

What does everybody else with a lift do for the front drive shaft? I'm thinking about removing my 8'' Fabtech and going with a 4''. We have long cold winters in Manitoba and I need to be able to drive 60mph in 4x4. Most of the lifts I've looked at don't mention anything about the front drive shaft (other than Cognito)

Most use the stock driveline without issues, 4" of lift isn't much. 95% of the Cognito 4" packages do not even order the driveline. OP, I'd be looking into Ujoint issues that the added recent angle change accelerated.