Rear Driveshaft Replacement

[Darksky]

Who has replaced their factory rear driveshaft:

Why?

What brand or what type of custom build?

Type of mods to driveshaft? Steel vs. Aluminum  heavier/thicker walled/stronger 

Length added to accommodate lift kit?

Heavier U Joints?

Two piece?

Cost?

Results?

Additional Advice or comments?

 

Feel free to add in any field I neglected to mention.

*I searched, but did not find a dedicated replacement driveshaft thread.

 

[DenaliX14]

[DenaliX14]

Also, 

 

http://www.driveshaftspecialist.com/Truckhtml/Chevy-GMC.html

 

They can help you. 

[flyingfool]

i see no point , the drive shaft is  only an issue if your drag racing or going over 100mph, or make over 400hp. save your money

Edited January 29, 2019 by flyingfool

[imiller1974]

70.5" long, 5" diameter aluminum driveshaft from shaftmasters.com. $675+ shipping.

[SS502]

On 1/28/2019 at 9:10 PM, flyingfool said:

i see no point , the drive shaft is  only an issue if your drag racing or going over 100mph, or make over 400hp. save your money

You’re obviously speaking RWHP right?

[kennerz]

This is not high on the mod list for me but I would definitely consider it. A well made stronger balanced shaft would give a noticeable gain in drivability I would think. Seen the photos of the failures on the newer trucks, not pretty. Also I think many of the vibration problems stem from the factory shaft. Read other threads where vibrations were eliminated from switching to an aftermarket shaft from a reputable vendor.

 

The factory construction is surprising. soo thin... plus on a 6.2 LT that wheel HP level or close to is just a few mods away. A tuned truck will do 100mph effortlessly , the terminal shaft speed of a stock truck is way below a quality balanced shaft. (not advocating speeding). But in the overall scheme of mods seems like it would be worth it. These truck really improve when you replace crappy factory volume parts where they cut corners with solid high performance equipment. They are too fast and powerful to ignore upgrading the generic parts and they don't need much to get a high level of feel and performance. I say do it.

 

the guys in the link in the first post have a great reputation in the muscle car world as well as trucks.

[Darksky]

Well said, kennerz. I will let you know how it progresses.

 

[DenaliX14]

On 1/29/2019 at 10:25 AM, imiller1974 said:

70.5" long, 5" diameter aluminum driveshaft from shaftmasters.com. $675+ shipping.

is that what you purchased personally? I'm looking at significant jump in HP with my 14 Denali 6.2L. I have some real concerns for my OEM Driveshaft. 

[imiller1974]

Yes.

[300 Blackout]

I have the exact same driveshaft as imiller1974 from the same company.

I’ve got 4.56 gears and at 70mph my shaft is spinning the equivalent rpm of going ~92mph with the stock 3.42 gears. I upgraded the driveshaft due to concerns about being too close to the critical speed of the stock shaft. Essentially, I wanted a bigger margin of safety.

The new driveshaft can handle over 6k rpm which equates to around 140mph with my 4.56 gears and 33.5” tires. It also maxes out around 10k lbs-ft of torque.

I would be more worried about how fast it’s spinning rather than how much HP or TQ you’re producing. In the driveshafts I’ve looked at, critical speed was always the limiting factor.

1SLOW1500 prefers two piece steel shafts. You might want to send him a PM for his input as to why.

[Big Pimpin Denali]

On ‎1‎/‎29‎/‎2019 at 8:25 AM, imiller1974 said:

70.5" long, 5" diameter aluminum driveshaft from shaftmasters.com. $675+ shipping.

Did you end up getting this shaft for your truck? I am looking to get a new shaft built for mine. Its seems that our trucks have weird/non replaceable ujoints?

 

[imiller1974]

Yeah, I have the driveshaft for the truck, why would I post otherwise... U-joint is a 1415 AAM, nothing special or weird about it, has the same bearing caps as a 1410 and 1350, just the cross section is different. Can get them from Denny's driveshaft for $23.

[lucas287]

Reviving this thread. Thinking about replacing my rear DS on my truck in the sig. 

 

Does anyone know the specs of the stock DS? Specifically, the diameter, length (67"?), and the wall thickness?

 

There's a phenomenon called half critical speed vibrations and that might be the reason why driving above 80 is miserable in my truck. 

[lucas287]

Wow, can't believe it's been a year and I still haven't replaced my driveshaft. I was actually about to buy a couple UJs and a strap kit and see if that helps (only ~$75) but the last time I messed with a GM driveshaft I ended up bending the ears on the yoke because they used injection molded plastic retainers  

 

I've got vibes that start right around 78 and worsen by 85 and then taper off again. Makes cruising on TX highways a real pain. I'm either speeding or stuck in the slow lane. Almost certain that has me hitting a DS RPM that just doesn't jive well with the stock construction. I'm also noticing that my truck is real sensitive to pinion angle changes which makes me think that a UJ is worn, I have a balance issue, or some combo of the two. 

 

Anyways, it got me thinking of the golden rule of modding: buy once cry once. I think I'm just gonna pull the trigger on a new shaft and be done with it. Performance Drivelines out of Bakersfield, CA has one for less than $600 shipped!