Driveshaft vibration

Drivetrain discussion including Transmission, Differential, Driveshaft, and related items.
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xten57
Posts: 21
Joined: Wed Jan 06, 2021 2:29 pm
Location: SoCal

Driveshaft vibration

Post by xten57 »

Hello, everyone,

I have searched the archives here hoping to find some information about possible sources of vibration in the drive train. Since I was unable to locate any threads that describe my problem, I'll post a question and hope that someone here can shed some light on what I'm experiencing.

First, thanks in advance for taking the time to this thread, and for answering, if you do. I've been a car guy for a long time, but this is my first PPV (a 2013). I've had the car for about six months and it's been my daily drive, I've put about 15K miles on it in that time. There has always been a very slight vibration while driving at highway speed, but last week this "new" vibration started.

The vibration becomes noticeable above 40MPH, and seems to smooth out as speed increases, but doesn't go away. I tried shifting into neutral at 55MPH, and the vibration goes away. I also raised the engine RPM to 2K while coasting at 55PMH, and no vibration. I put it back into Drive, and the vibration immediately returns.

I haven't been able to get under the car to visually inspect anything yet. Any ideas for troubleshooting this?

Thanks again
Gerry
2013 9C3, metallic black, L77 with headers/X-pipe, DOD delete, cold-air intake, LS3 cam.
GammaFlat
Posts: 259
Joined: Mon Sep 21, 2020 9:26 am
Location: NW Indiana

Re: Driveshaft vibration

Post by GammaFlat »

First guess: U-Joints or carrier bearing.

Has the differential been changed or drive shaft maintained? From FudgeHog in this thread: http://www.newcaprice.com/forum/viewtop ... =36&t=2934:
"After noticing a perceived driveshaft vibration from the Camaro flex plate, I bolted the Caprice one back on, and it seems much better. Some of it could be the alignment as well. I'll find out."

I've done one differential in a Caprice and I made sure to mark everything so that parts wouldn't be "off by 120 or 240 (3 bolts)" when I re-assembled. I have not heard this but if the drive shaft is balanced as a unit, "clocked wrong" could be bad.
Current: 2013 9C3, deeper trans pan, 12VoltSolutions Remote, Class III hitch, Android Auto capable radio
xten57
Posts: 21
Joined: Wed Jan 06, 2021 2:29 pm
Location: SoCal

Re: Driveshaft vibration

Post by xten57 »

The car was born with a V6, and the L77 swap was done by a very competent shop, but I don't know if they replaced the differential or driveshaft during the swap. Something may have done with the driveshaft because the car now has a 6L80. I'll have to crawl under it sooner rather than later to see what's up. But I guess I'll be looking at the trans mount, couplers, and the center carrier bearing.

Thanks for your reply, GammaFlat
Gerry
2013 9C3, metallic black, L77 with headers/X-pipe, DOD delete, cold-air intake, LS3 cam.
xten57
Posts: 21
Joined: Wed Jan 06, 2021 2:29 pm
Location: SoCal

Re: Driveshaft vibration

Post by xten57 »

I got under the car and looked around. I discovered that a bolt is missing from the front of the drive shaft, where it bolts to the Giubo. I will have to source some from GM. None of the local dealers in my area stock them. After reading some of the other related posts, I think it will be best to replace all three bolts at the front, and have some on hand to replace the rears, eventually.
Gerry
2013 9C3, metallic black, L77 with headers/X-pipe, DOD delete, cold-air intake, LS3 cam.
Navy Lifer
Administration Staff
Posts: 1724
Joined: Tue Mar 19, 2013 6:30 pm
Location: Canton GA

Re: Driveshaft vibration

Post by Navy Lifer »

What is your reference to the "Giubo" - the flange on the transmission or the drive shaft damper to the prop shaft itself?

Are you referring to bolt PN 92139225? This bolt threads into the "tri-wing" output shaft flange at the back of the transmission.
https://www.rockauto.com/en/moreinfo.ph ... 632&jsn=19

If it's a missing bolt & nut, I'm not sure whether they are serviced separately or as part of the drive shaft damper (rubber donut)
https://www.gmpartsdirect.com/oem-parts ... xleA%3D%3D
xten57
Posts: 21
Joined: Wed Jan 06, 2021 2:29 pm
Location: SoCal

Re: Driveshaft vibration

Post by xten57 »

Navy Lifer wrote: Tue Jul 13, 2021 7:14 am What is your reference to the "Giubo" - the flange on the transmission or the drive shaft damper to the prop shaft itself?

Are you referring to bolt PN 92139225? This bolt threads into the "tri-wing" output shaft flange at the back of the transmission.
https://www.rockauto.com/en/moreinfo.ph ... 632&jsn=19

If it's a missing bolt & nut, I'm not sure whether they are serviced separately or as part of the drive shaft damper (rubber donut)
https://www.gmpartsdirect.com/oem-parts ... xleA%3D%3D
In reference to the Giubo, I mean the rubber flex joint between the transmission output shaft and the prop shaft (or prop shaft to diff flange). The missing bolt was one of the three that attach the prop shaft to the flex joint (Giubo), and is listed as PN 92228335. The nuts and washers are
PN 92228333 and PN 92228334, respectively. When I called the two dealers closest to me, neither parts guy could find the PN for the bolts. I located them through one of your posts in a thread here:
http://www.newcaprice.com/forum/viewtop ... 7&start=60

Thanks for following up, I appreciate it.
Gerry
2013 9C3, metallic black, L77 with headers/X-pipe, DOD delete, cold-air intake, LS3 cam.
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