Jump to content
  • Sign up for FREE! Become a GM-Trucks.com Member Today!

    In 20 seconds you can become part of the worlds largest and oldest community discussing General Motors, Chevrolet and GMC branded pickups, crossovers, and SUVs. From buying research to owner support, join 1.5 MILLION GM Truck Enthusiasts every month who use GM-Trucks.com as a daily part of their ownership experience. 

Recommended Posts

14 minutes ago, truckguy82 said:

I’m pretty certain the limitation with driveshaft speed is all about the factory balance. I’m sure they have sloppy balance specs evident by so many people having shaking issues. If you driveshaft is on the upper limit of that spec and is out of balance your top speed will be lower. If it’s near perfect by coincidence, you should have driveshaft speed limitation of well over 300mph.

 

A perfectly balanced spinning steel tube could probably handle 100,000 rpm before the rotational g forces rip it apart.

 

Nope, it's critical speed which comes from the design specs.  Balance plays a role, but is not the deciding factor.

 

https://spicerparts.com/calculators/driveshaft-safe-operating-rpm-calculator

 

http://pstds.com/critical-speed-chart/

 

https://www.markwilliams.com/driveshaft-tech.html

 

 

  • Like 1
Link to post
Share on other sites
  • 1 month later...
  • Replies 81
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Popular Posts

The Max Speed really depends on the level of education, life and street smarts. I’ve got a 6.2 with a small tune, no limiter [emoji6], that’s a beast but it’s not my Sports car which is designed to go

Im pretty sure I didn't endanger anyone when I wound her up to 97 the other day. I'd be more worried about the dumb shits that are texting and driving if I were you.  Let's get back to talkin tru

SS502 is unraveling me    A speed limit is no different than which side of the road to drive on. Here we've all decided to do so on the right side in this country.   Made a social c

Screw it.  I'll leave the limiter, driveshaft, and entire truck alone aside from exhaust, intake, long tubes, and a tune...  and get my go-fast fix with a Gen6 Camaro SS.

Link to post
Share on other sites
  • 1 month later...

I took my 2017 Silverado  W/T Reg Cab long bed out today to see where the speed limiter was set, but more so to check for any vibrations. 

Smooth as glass right to 110 and everything in between. , didn’t want to push the issue, but so much for the 100mph limiter!!!

BTW, the truck is a 5.3 4WD with 6 speed transmission, stock tires, with 3:42 gears.  

Truck felt like it had much more in it, but didn’t want to test some CHP’s radar gun. 

 

Edited by Slvijoe
  • Like 1
Link to post
Share on other sites
  • 3 weeks later...
  • 4 months later...

I just had my 2020 Sierra over 110mph 30 minutes ago. I kept waiting for it to shut off at 98 or so and it just kept climbing. Because of terrain, I let up at about 112 or so. Needless to say, I was surprised......pleasantly!

Link to post
Share on other sites
  • 3 months later...

If you believe the critical speed calculations the limiters are set based on the driveshafts. Test drove 2 different z71s and 3 2wd trucks. First 2 did 112. Other 3 all 99. Calculate the critical speed and you’ll see in the 2wd 4 door trucks, the one piece 75” shaft will jump rope at about 110-115. I’m going to get a 2 piece because I do not trust the stock 5” .080 aluminum foil shaft. 

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Similar Content

    • By austinhite
      I have a 2017 Chevy Silverado 4x4 5.3l V8 with the 8 speed transmission. I already flushed out my transmission and filled it back up with the Mobil 1™ Synthetic LV ATF HP blue label. The question is, do i also use the HP fluid for my transfer case? Or do i need to use just a standard ATF fluid instead. I cant seem to find a straight answer on this. The owners manual states to use DEXRON®-VI Automatic Transmission Fluid. Would using regular ATF in the transfer case and HP ATF in the transmission cause any issues? Thanks in advance!
    • By jenglish421
      So I have a 2017 GMC Sierra 1500 with the 5.3 at 35k miles and I got a flashing CEL for about 30 seconds a few weeks ago on the highway and took it it to auto parts store but it had no codes present. About a week and a half ago the CEL came on constant and it came up with the P50D Rough Idle and so I got oil changed and ran some fuel system cleaner through and after a couple days the light started flashing and ran rough for a few min, I parked it and started it 10 min later and it was a solid CEL again but I was able to pull a P300 General misfire code. Today it did the same thing but ran worse than ever and I thought it was going to die on me, shut it down for 10 min and it ran ok. Before I start throwing money at this where should I start, spark plugs, coil packs, injectors? I'm at a loss with only 35k and just passed the 3yr warranty. Thanks for any advice.
    • By VinceWeiss
      I have an 06 Silverado with 215k miles. Has the L33 Aluminum Block 5.3 in it. It runs great, has good power, but has an odd ticking/knocking noise. It doesn’t make the noise until it’s been running for about a minute so I don’t think it’s exhaust. I also do not think it’s a lifter because it sounds more lower end towards the rear of the engine. Has anyone had any experience with these L33s knocking? It has been making this noise for a while now and it’s very annoying/embarrassing. I’m not sure if oil has anything to do with it but I use penzoil 5w30 full syn. Let me know if you have any ideas, thanks.
    • By Fortino510
      Hello im new to this forum. I have been searching for silimar sounds my truck is making on here but i can't seem to find one. So my truck is a 2020 silverado rst 5.3 8 speed crewcab 4x4 and has 1,600 miles. It makes this clicking sound similar to a clock. I went underneath the truck to listen for the sound and it appears to be coming from transmission area. Any thoughts of what the sound is? Ill attach a sound clip. Its a cold start but it also does it when its warmed up.
      20201103_053649_2_1.mp4
    • By _Elmwood_GM
      I have read hundreds of AFM collapsed lifter threads but have not been able to find someone with my same issue where it has been solved.  Looking for your expertise in the cause, not looking for advise to turn AFM off as that is the plan but I want to properly fix the issue first.  
       
      I have a 14 Silverado with a 5.3 with 50k miles and the issue I’m having is there is a pecking/knocking/rattle only when the truck is under light load while it is in V4 mode.  Has anyone else experienced this where the noise occurs only while in V4 and while slightly accelerating?  
       
      The are no check engine lights, no noises at idle, no noise while running on 8 cylinders, no smoke, no oil usage, and it doesn’t appear to have lost any power.   
       
      The two possible problems I see are either:
      1. One of the AFM lifters have failed in a way where it is not allowing the cylinder to deactivate which means the intake or exhaust valve will function like normal instead of closing during V4 mode.  If this is the case is there any way to confirm this without a diagnostic scanner to put the truck in V4 at idle or to deactivate each cylinder?  Is there any risk of further failure by not fixing this if I turn off AFM as it seems the “tabs” are just not disengaging within the lifter? 
      2. There is an issue somewhere within the VLOM portion with an actuator, oil port, something electronic that is preventing enough oil pressure to deactivate the lifter.  If AFM is deactivated is there any risk with whatever is not working properly within this system?  
       
      Basically, I am fine with turning AFM off as where I drive there is likely minimal impact but I don’t want to turn it off just to cover up a problem that will resurface in the near future as I don’t intend on getting rid of the truck any time soon. 
  • Recently Browsing   0 members

    No registered users viewing this page.

  • Forum Statistics

    230,933
    Total Topics
    2,465,749
    Total Posts
  • Member Statistics

    231,132
    Total Members
    8,960
    Most Online
    Phillip gray
    Newest Member
    Phillip gray
    Joined
  • Who's Online   53 Members, 1 Anonymous, 3,119 Guests (See full list)




×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.