Finally Ordered it!

[farmtruc]

Before I start:
Like an engine; tubing for driveshafts also have an rpm limit called critical speed. The manufacturer of the tubing determines the critical speed base on length and diameter. For example, two ds's that are 60" long, one 3" and one 3.5", will have different critical speeds. The 3" will have a critical speed somewhere around 3300rpms, the 3.5" will have one that is higher. Aluminum also, increases the critical speed when compared to steel.
You'll find out when you reach critical speed becuase you shaft will explode in the middle and cause damage to your truck, ask me how i know, lol!!

I've been thru 3 shafts already and i'm still experiencing vibrations. The vibration is noticeable starting at 75mph. It gets worse as i increase mph.
With my 4.10 gears and overdrive, the shaft spins a lot faster than with my 3.42's.

So, after installing my third shaft and still having vibes, i've had it. This shaft was made of 3.5" steel tubing and i'm still getting vibration. Although, my new aluminum one is also 3.5", i was told aluminum has a much higher critical speed. Critical speed isn't the only problem i have, most local shops can only spin a shaft about 1-2K rpms, that is no where near enuff to fully balance a shaft. I don't think at 75mph i'm reaching critical speed, i think i'm experiencing a poorly balanced shaft. I was told i could send my shaft in and get it rebalanced, but after shipping, balancing, and the cost of resizing my dshaft, I decided to have one built. btw, the local shop built my dshaft a little too long and it's a pita to remove the shaft, we had to use a pry bar to push it forward so that i could remove the caps, then it would come out.

After all this, i ordered this.
My new shaft

I got a 3.5" Heavy Duty Aluminum driveshaft
Greaseless spicer HD joints
HD trans yoke
1350series pinion yoke(comes with straps, bolts, seal, greased)

This thing better fix my problem, if it does, i may be off line for a while cause i just may throw the current dshaft threw my local shops window.

I'll keep ya'll updated,

allen

[Sleeper]

NIIIIIICE! definitely let me know how it works. thats the same one i was lookin at the other night....ouch $460...dont tell the wife

Brandon

[farmtruc]

She already said i could, but i'm too stubborn to buy it, i really wanted it to be something else, plus spending all that money sux.

don't forget to add the $94 dollars for the HD pinion yoke, and $35 shipping, ouch. i hate that,



allen

[GMCwantsLS1]

I agree it is expensive but the better grede of aluminum and the high speed ballancing (not to mention tearing the crap out of the bottom of your truck) if done properly should fix your problems and should be worth the expense !!

[farmtruc]

The one i'm getting is made of stronger aluminum.
Take a stock camaro shaft and notice how light and soft the aluminum is. That is the 6061-T6 aluminum, notice you can scar or mark it with a knife or rock, this is the LT aluminum shaft, somewhat strong, but not stronger than the HD aluminum, which has a metal mix in the aluminum. hopefully this will cure my problems and i can finally see how fast my truck goes, heheheh, now that i have the new kuhmos.

later,

allen

[GMCwantsLS1]

Cool how do you like your new tires?

[99 red silver]

Top end 225. Lets see. Hope this fixes the problem and you can make it up that hill.

[6gear]

I talked to Denny's Driveshafts myself monday and I had decided to go that route myself, they told me the same thing that when you run low gears and high highway speeds that a standard shaft can't handle the strain, my T56 has a finer spline and smaller dia. then my 5 speed trans. so I was going to have to buy a new yoke and get my other shaft modified but with the problems you have had and the money it would take to modify mine I decided to go with Denny's. I printed the forms they have on there web page to get the proper measurements but it will probably be Sat. before I get the engine and trans. stuffed back in to get measurements. Let us know how your shaft works out, they told me 2-3 weeks turn around time.

[DBYRD]

i know this thread is really really old, but if i go 3.73's on my truck would i need a new driveshaft? i plan on making a driveshaft loop soon as well just to be safe. also anyone know how this turned out?

[zeake]

<div class='quotetop'>QUOTE(Allstar55566 &#064; Apr 19 2007, 03&#58;03 AM) [snapback]90521[/snapback]</div>

i know this thread is really really old, but if i go 3.73&#39;s on my truck would i need a new driveshaft? i plan on making a driveshaft loop soon as well just to be safe. also anyone know how this turned out?
[/b]

I would use the stock one till it heads south. The loop will help if you are 2 wheel drive My 4 wheel drive reg cab did not need one when my rear end went south and took everything but the transfer case with it. The replacement shaft was from another good shop. Not as good as Dennys It still vibrates some. I will upgrade to a Dennys aluminum one day.

See carnage here. http://putfile.com/zeake/images/76032