Gears & Axles Driveshafts | Rearends | Differentials | Gears | 12 Bolt | 9 Inch | Dana

Driveshaft Mod, input please.

Thread Tools
 
Search this Thread
 
Old Dec 7, 2016 | 06:45 AM
  #1  
silversrtman's Avatar
Thread Starter
TECH Enthusiast
15 Year Member
iTrader: (20)
 
Joined: Sep 2005
Posts: 741
Likes: 0
From: Carmel, NY
Default Driveshaft Mod, input please.

Hey all. We all have those issues with our cars that really, really get to us. Mine is driveline vibrations. I could never really dial in my pinion angle 100% so a buddy of mine suggested I do a double cardan u joint setup which basically turns a 1 piece 2 ujoint driveshaft into a shaft with a cv joint to which pinion angle doesn't matter. Long story short, I shortened my driveshaft to accommodate what I thought was a double cardan. Upon further research what I did is actually called an H joint setup. After I pressed all the ujoints in I saw that the driveshaft was really floppy. Even though I knew I was screwed at that point I installed in anyway hoping that if its bolted to the rear itll be ok. Well, its not. If I were to drive the car like this at the very least my tailshaft would get destroyed. So my question to any experts out there. Is there anything I can do with my current Hjoint setup that would fix floppiness? A true double cardan would but the parts seem expensive and I don't know exactly what I would need and then I will have to grind the weld down to separate the yoke which is terrible lol. Ive attached pics. Also I know a new driveshaft is an option but I would rather somehow fix mine to make it a cvjoint so I could get rid of my vibes. Worst case Ill buy a new shaft or make my own. Thanks in advance.
Attached Thumbnails Driveshaft Mod, input please.-img_4639.jpg   Driveshaft Mod, input please.-img_4640.jpg  
Reply
Old Dec 7, 2016 | 08:44 AM
  #2  
Bob@BruteSpeed's Avatar
LS1Tech Sponsor
20 Year Member
Active Streak: 30 Days
Active Streak: 60 Days
Liked
iTrader: (16)
 
Joined: Mar 2003
Posts: 21,020
Likes: 35
From: Roanoke, IN
Default

You need a new driveshaft, what you currently have is an accident waiting to happen. Bob
__________________
ATI ProCharger and Moser Sales 260 672-2076

PM's disabled, please e-mail me
E-mail: brutespeed@gmail.comob@brutespeed.com

https://brutespeed.com/ Link to website


Reply
Old Dec 7, 2016 | 08:47 AM
  #3  
silversrtman's Avatar
Thread Starter
TECH Enthusiast
15 Year Member
iTrader: (20)
 
Joined: Sep 2005
Posts: 741
Likes: 0
From: Carmel, NY
Default

Yeah I know it is. As soon as I picked it up to install it and saw how floppy it was I knew I was screwed. Thanks for the reply Bob. Do you think it's worth converting it to an actual double cardan setup with the ball in the middle of the ujoints? Some cars come like this from the factory
Reply
Old Dec 7, 2016 | 08:50 AM
  #4  
Bob@BruteSpeed's Avatar
LS1Tech Sponsor
20 Year Member
Active Streak: 30 Days
Active Streak: 60 Days
Liked
iTrader: (16)
 
Joined: Mar 2003
Posts: 21,020
Likes: 35
From: Roanoke, IN
Default

Originally Posted by silversrtman
Yeah I know it is. As soon as I picked it up to install it and saw how floppy it was I knew I was screwed. Thanks for the reply Bob. Do you think it's worth converting it to an actual double cardan setup with the ball in the middle of the ujoints? Some cars come like this from the factory
No, I would go with a good balanced aftermarket driveshaft in the correct length. Bob
__________________
ATI ProCharger and Moser Sales 260 672-2076

PM's disabled, please e-mail me
E-mail: brutespeed@gmail.comob@brutespeed.com

https://brutespeed.com/ Link to website


Reply
Old Dec 7, 2016 | 08:56 AM
  #5  
Darth_V8r's Avatar
Moderator
10 Year Member
Liked
Loved
Community Favorite
iTrader: (4)
 
Joined: Jul 2014
Posts: 10,451
Likes: 1,873
From: My own internal universe
Default

My 2 cents - if you're going to dump some coin anyway, consider a carbon fiber driveshaft. It does a few things for you. Shifts the natural resonance frequency higher than the thing will ever spin. Absorbs some of the engine surge if you're cammed. Lighter - though that likely isn't too much a help. And if it breaks, it'll just clean the bottom of the car for you without causing any damage.

It actually helped quiet my car down considerably - and that is saying something!
Reply
Old Dec 7, 2016 | 09:07 AM
  #6  
silversrtman's Avatar
Thread Starter
TECH Enthusiast
15 Year Member
iTrader: (20)
 
Joined: Sep 2005
Posts: 741
Likes: 0
From: Carmel, NY
Default

Originally Posted by Bob@BruteSpeed
No, I would go with a good balanced aftermarket driveshaft in the correct length. Bob
damn, well it was worth a shot. You know what they say. Desperation is a stinky cologne. I just want to be able to take my car to speed without vibrating like a sharper image chair

Originally Posted by Darth_V8r
My 2 cents - if you're going to dump some coin anyway, consider a carbon fiber driveshaft. It does a few things for you. Shifts the natural resonance frequency higher than the thing will ever spin. Absorbs some of the engine surge if you're cammed. Lighter - though that likely isn't too much a help. And if it breaks, it'll just clean the bottom of the car for you without causing any damage.

It actually helped quiet my car down considerably - and that is saying something!
when you say it helped you, did you have vibrations? The noise isn't what bothers me it's just the vibes. I can take my car up to 80 and that's basically it without feeling like I'm going to break something. However, my driveshaft from the factory had very tiny little balancing washers welded onto it, when i cut it and shortened it and got it balanced they welded on these weights that were much bigger. I wonder if it was out of balance from the factory
Reply
Old Dec 7, 2016 | 09:10 AM
  #7  
MidwestChassis2's Avatar
TECH Fanatic
iTrader: (1)
 
Joined: Jan 2015
Posts: 1,504
Likes: 39
Default

Maybe we can tackle your issue in another way. Give me some details of what all is done to your vehicle as far as suspension, what transmission, and what rear end. Also what driveshaft you have been using and if it was high speed balanced.

This is all assuming you balanced your wheels during this process to rule that out.
Reply
Old Dec 7, 2016 | 09:14 AM
  #8  
MidwestChassis2's Avatar
TECH Fanatic
iTrader: (1)
 
Joined: Jan 2015
Posts: 1,504
Likes: 39
Default

Reading your latest response it very well could of been the stock driveshaft giving you issues. Hard to say at this point but like mentioning you need to start with a new and keep your fingers crossed that was it, however if not we could revisit the issue and see if we can help figure it out with you.
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-1

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-2

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-3

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-4

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-5

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-6

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

 Verdad Gallardo
story-7

Awesome K5 Blazer Restomod Comes With C7 Corvette Power

 Verdad Gallardo
story-8

10 Camaros You Should Never Buy

 
story-9

10 LS Engine Myths That Refuse to Die

 Verdad Gallardo
Old Dec 7, 2016 | 09:35 AM
  #9  
silversrtman's Avatar
Thread Starter
TECH Enthusiast
15 Year Member
iTrader: (20)
 
Joined: Sep 2005
Posts: 741
Likes: 0
From: Carmel, NY
Default

Originally Posted by MidwestChassis2
Reading your latest response it very well could of been the stock driveshaft giving you issues. Hard to say at this point but like mentioning you need to start with a new and keep your fingers crossed that was it, however if not we could revisit the issue and see if we can help figure it out with you.
thank you. Yes my wheels are balanced correctly and everything is setup correctly to
my knowledge. I got my pinion angle as close as I could in line with my driveline angle and it was still pretty bad. I have a Dana 60 and before I cut it up I had their 3" chromoly shaft but like I stated above after taking 3" off the driveshaft the local place that balanced it put way more weight on it which doesn't make sense which leads me to believe it wasn't balanced correctly. I never even thought to try to have the shaft balanced. I saw the weights and assumed (whoops) that it was correct. As far as suspension I have hotchkis lowering springs, umi adjustable torque arm, umi sways, sfcs, adjustable panhard rod, lower control arms. My rear has lower control arm relo brackets welded on as well. Thanks again for the reply
Reply
Old Dec 7, 2016 | 10:04 AM
  #10  
MidwestChassis2's Avatar
TECH Fanatic
iTrader: (1)
 
Joined: Jan 2015
Posts: 1,504
Likes: 39
Default

What transmission? If it is a T-56 that may be your problem and not pinion angle or driveshaft balance. This is the reason we have since gone to Sonnex yokes with any T-56 transmission when we sell a driveshaft.
Reply
Old Dec 7, 2016 | 10:11 AM
  #11  
silversrtman's Avatar
Thread Starter
TECH Enthusiast
15 Year Member
iTrader: (20)
 
Joined: Sep 2005
Posts: 741
Likes: 0
From: Carmel, NY
Default

Originally Posted by MidwestChassis2
What transmission? If it is a T-56 that may be your problem and not pinion angle or driveshaft balance. This is the reason we have since gone to Sonnex yokes with any T-56 transmission when we sell a driveshaft.
whoops knowing the tranny is pretty important lol. Yes it's a t56. Why are the sonnex yolks better ?
Reply
Old Dec 7, 2016 | 10:29 AM
  #12  
MidwestChassis2's Avatar
TECH Fanatic
iTrader: (1)
 
Joined: Jan 2015
Posts: 1,504
Likes: 39
Default

Originally Posted by silversrtman
whoops knowing the tranny is pretty important lol. Yes it's a t56. Why are the sonnex yolks better ?
They have better tolerances.
Reply
Old Dec 7, 2016 | 12:19 PM
  #13  
Darth_V8r's Avatar
Moderator
10 Year Member
Liked
Loved
Community Favorite
iTrader: (4)
 
Joined: Jul 2014
Posts: 10,451
Likes: 1,873
From: My own internal universe
Default

Originally Posted by silversrtman
when you say it helped you, did you have vibrations? The noise isn't what bothers me it's just the vibes. I can take my car up to 80 and that's basically it without feeling like I'm going to break something. However, my driveshaft from the factory had very tiny little balancing washers welded onto it, when i cut it and shortened it and got it balanced they welded on these weights that were much bigger. I wonder if it was out of balance from the factory
It helped with Noise, Vibration, and Harshness all three in general. MWC is giving you some good info in this thread.

One thing I thought I'd mention is this - At 65 MPH, assuming you're in 3.42 or higher gearing, the wheels are turning roughly 17 revs per second. Think of this as 17 Hz. You can't hear it, but you'll feel every pulse in your gut or on the steering wheel, etc. On the driveline, that 17Hz is more like 55-70 Hz depending on gearing. That's vibrating fast enough to fill the car with a bassy drone, but you won't feel the individual pulses. At 80 mph, the frequencies are a little higher, but the principle is the same. So typically, if you're feeling the vibrations bu not hearing that drone, the first thing I tell someone is to check everything wheel-side. Balance, bubbles in tires, rotors bent wheels, bent axle shafts, etc. If its a shudder that is accompanied by that bassy drone I typically start looking at the driveline
Reply
Old Dec 7, 2016 | 01:12 PM
  #14  
silversrtman's Avatar
Thread Starter
TECH Enthusiast
15 Year Member
iTrader: (20)
 
Joined: Sep 2005
Posts: 741
Likes: 0
From: Carmel, NY
Default

Originally Posted by Darth_V8r
It helped with Noise, Vibration, and Harshness all three in general. MWC is giving you some good info in this thread.

One thing I thought I'd mention is this - At 65 MPH, assuming you're in 3.42 or higher gearing, the wheels are turning roughly 17 revs per second. Think of this as 17 Hz. You can't hear it, but you'll feel every pulse in your gut or on the steering wheel, etc. On the driveline, that 17Hz is more like 55-70 Hz depending on gearing. That's vibrating fast enough to fill the car with a bassy drone, but you won't feel the individual pulses. At 80 mph, the frequencies are a little higher, but the principle is the same. So typically, if you're feeling the vibrations bu not hearing that drone, the first thing I tell someone is to check everything wheel-side. Balance, bubbles in tires, rotors bent wheels, bent axle shafts, etc. If its a shudder that is accompanied by that bassy drone I typically start looking at the driveline
yes midwest has been very helpful. There's definitely a noise associated with the vibes and I know my tires and wheels are in good shape, plus this isn't the only set of wheels and tires that I've had vibes with. Btw I checked out the prices of cf shafts and those are out of the question unfortunately
Reply
Old Dec 7, 2016 | 01:38 PM
  #15  
MidwestChassis2's Avatar
TECH Fanatic
iTrader: (1)
 
Joined: Jan 2015
Posts: 1,504
Likes: 39
Default

Originally Posted by silversrtman
yes midwest has been very helpful. There's definitely a noise associated with the vibes and I know my tires and wheels are in good shape, plus this isn't the only set of wheels and tires that I've had vibes with. Btw I checked out the prices of cf shafts and those are out of the question unfortunately
The carbon shafts are substantially higher than the alternatives for sure and like Darth_V8r mentioned they do give many benefits. I use one for the safety factor myself.

With that said even a PST 3" steel would work for you for a good quality replacement. Keep in mind we are the only ones selling their shafts with the Sonnax yoke.

Don't be afraid to check out local shops for a driveshaft build, just make sure to use a good yoke and I would check the tailshaft for excessive wear to make sure that isn't the issue either.
Reply
Old Dec 7, 2016 | 05:58 PM
  #16  
Bob@BruteSpeed's Avatar
LS1Tech Sponsor
20 Year Member
Active Streak: 30 Days
Active Streak: 60 Days
Liked
iTrader: (16)
 
Joined: Mar 2003
Posts: 21,020
Likes: 35
From: Roanoke, IN
Default

An aluminum driveshaft is going to transmit fewer vibrations that a steel driveshaft, I'd try to go aluminum if you can afford to do so. Bob
__________________
ATI ProCharger and Moser Sales 260 672-2076

PM's disabled, please e-mail me
E-mail: brutespeed@gmail.comob@brutespeed.com

https://brutespeed.com/ Link to website


Reply
Old Dec 7, 2016 | 07:10 PM
  #17  
01ssreda4's Avatar
TECH Senior Member
15 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (96)
 
Joined: Aug 2007
Posts: 24,241
Likes: 89
From: Turnin' Wrenches Infractions: 005
Default

True high speed balanced PST shaft and zero pinion angle and you can rule that out as your vibration source.
Reply




All times are GMT -5. The time now is 06:19 PM.

story-0
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-1
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-2
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-3
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-4
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-5
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-6
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-7
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-8
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-9
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE