jerking in drivetrain - Diesel Place : Chevrolet and GMC Diesel Truck Forums
 
Home Forum Market Place Garage Tuning Library DTC Tool Register Vendors
Go Back   Diesel Place : Chevrolet and GMC Diesel Truck Forums > Other Vehicles > GM Gassers
Register FAQ Forum Rules My Replies My Threads Mark Forums Read Advertise

GM Gassers Discuss any of the GM gas engines & associated components.

DieselPlace.com is the premier Duramax Diesel Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools
Old 11-12-2019, 03:52 AM   #1 (permalink)
davester
Diesel Prodigy
 
Join Date: May 2015
Posts: 4,277
iTrader Score: 0 reviews

jerking in drivetrain

I've had a vibration while driving between about 10-20 mph, and at speed (about 40 and over), when needing power like going uphill, in either 3rd or OD, I'll occasionally feel a momentary jerk, like just for an instant, power stopped being transmitted to the wheels. It's happening more often now, but it's not periodic (as in, like a missing tooth in a ring gear).



The engine doesn't speed up at all when this happens, and there are no engine or transmission codes. I rebuilt the transmission and installed a Transgo 4L80E-HD2 about 50k miles ago, and the u-joints & carrier bearing were replaced at the same time, and the driveshaft was balanced (it was also shortened to make room for the transfer case). In hindsight, I should have also replaced the torque converter, but it seems to be working fine. A couple months back, I replaced the transmission filter & fluid, and there was just the usual small amount of fine silt in the pan, and the fluid didn't smell burnt at all.



A brief check under the truck, I noticed I can move the driveshaft in the carrier bearing quite a bit (I can move it more than 1/4" up and sideways), so it needs replacement.


From googling, the low speed vibration can be due to the carrier bearing, but it's not clear if that jerking could also be due to it, or if the jerking could be from something else.


Idea/comments on what the problem could be?

__________________
2004 GMC Sierra 3500 C&C, added 4WD, 6.0L gas, Extended Cab, SLE, Transgo 4L80e-HD2 kit installed
Whee! Dually Club Member #1109
Offline  
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 11-12-2019, 04:59 AM   #2 (permalink)
davester
Diesel Prodigy
 
Join Date: May 2015
Posts: 4,277
iTrader Score: 0 reviews

As an aside, what would the gm part number be for the carrier bearing (also known as the center support bearing)?


From looking at rockauto, acdelco, and wholesalegmpartsonline.com, it's not clear which one is for my truck.


'04 Sierra 3500 cab&chassis, extended cab, 161.5" wheelbase, RWD (now 4wd)

__________________
2004 GMC Sierra 3500 C&C, added 4WD, 6.0L gas, Extended Cab, SLE, Transgo 4L80e-HD2 kit installed
Whee! Dually Club Member #1109
Offline   Reply With Quote Quick reply to this message
Old 11-13-2019, 01:00 PM   #3 (permalink)
Drakito
Diesel Fanatic
 
Drakito's Avatar
 
Join Date: Feb 2016
Location: Southern Utah
Posts: 130
iTrader Score: 0 reviews

Jerking on a loaded condition is usually a misfire, though your badly worn carrier bearing is also a culprit. The ECM can cut power without causing any RPM flares up or down by retarding the timing radically when it detects a misfire, making it feel like all the power went away(because it did). Personally I would get the bearing changed first, then test again. My reasoning on that is it is a known bad part that can make knocking or clicking noise and harmonics. The ECM monitors noise and harmonics from multiple sensors in the trans and engine. It could think it is knock, or something out of spec and cuts power temporarily, but not long enough or often enough to trigger a check engine light.

If it is still there after the bearing replacement I would put some higher grade fuel in from a different station to see if it cleans up. Like if you are using some Costco 87, throw in some Shell or Chevron 91 for a single tank. If it is still there after that start looking at plugs/wires, fuel pressure regulator, or fuel filter.

Most of these are easy checks or cheap easy to replace parts. Plugs take minutes to check, wires the same and are cheap to replace. OEM wires from rockauto are el cheapo. 10mm race wires can be had on ebay for cheap.

The FPR just remove the vacuum line inlet and see if there is any fuel, if there is, it is bad. If none, 99% chance it is fine.

Fuel filters are like $10.00 and 10 minutes to replace, yet everyone forgets about them. Its on the frame rail in front of the tank. Mine is right behind the ABS pump and in front of the tank, though I have an 8.1L suburban, multipl other GMs of thise chassis are in the same area. 2 open end wrenches and a 10mm wrench for the mount and it was swapped after about 6 minutes with the fuel draining.

The pumps can be on the way out, but usually they manifest in a hard start first.

If you had the 8.fun I could point you towards some sensors that are known to cause that, but am unsure if they do the same on the 6.0. The crank sensor on the 8.1 can cause the issue, as well as hard or no starts, but the 6.0 has a completely different crank sensor and location.
Offline   Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 11-13-2019, 03:56 PM   #4 (permalink)
davester
Diesel Prodigy
 
Join Date: May 2015
Posts: 4,277
iTrader Score: 0 reviews

Thanks for your response.


My truck is an '04, with the returnless fuel system, so the pump in the tank is the "all in one unit" (pump, fpr, and filter). I did plumb in an inline fuel filter like earlier trucks had, and it was replaced earlier this year with very little dirt in it.


Also recently (as in, 2 months ago) replaced plugs & plug wires, with no change.


Once I figure out which center support bearing to get, I'll replace it and see what happens. I'll also try hooking up a scanner and seeing if any misfires show up when viewing live data.
__________________
2004 GMC Sierra 3500 C&C, added 4WD, 6.0L gas, Extended Cab, SLE, Transgo 4L80e-HD2 kit installed
Whee! Dually Club Member #1109
Offline   Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Diesel Place : Chevrolet and GMC Diesel Truck Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

PLEASE READ! You must check your email inbox for the confirmation link to complete registration. Please check your spam box if you do not see the email in your inbox.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Insurance
Please select your insurance company (Optional)

Log-in


Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -4. The time now is 06:15 PM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Shoutbox provided by vBShout v6.2.1 (Lite) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd. Runs best on HiVelocity Hosting.
© AutoGuide