# Thumping from rear end. 2005 GTO



## Al52 (Apr 5, 2016)

Hi Guys,

My first post with a question that's probably been asked and answered numerous times already. Would prefer posting my own particular issue to get some input from those who have more experience with this particular GTO than I do. Purchased a one owner, near mint 2005 GTO last spring, dead stock with 26,000 miles. Noticed a slight thumping noise coming from the rear end, seemingly more on the right rear side, upon easing out the clutch and mildly accelerating in 1st gear. 5-6 palpable thumps, which then stopped and the vehicle was fine. No other noises or issues, just the thump. Took the vehicle back, mechanics came to conclusion that it was the traction control and not to worry about it. I've done my share of wrenching on my Pontiacs over the years but Father Time finally caught up with me in that regard, limiting what I can do now, but personally, and from my experience, I think the mechanics made the wrong call here. I'm thinking more of a differential, axle, or possible lubrication issue. Hard to swallow the idea that it's the differential with now only 28,000 miles on it, unless it suffered 26,000 miles of total abuse. I realize it's pushing 11 years of age, and perhaps something else is giving away as well. It hasn't worsened, just remains about the same, with or without the traction control engaged. This will probably be my last muscle car and I want to make sure everything is dead on. If it's a major issue, I'll probably have a GM dealer address it, but could use some ammunition information wise. If it's relatively minor issue, I'll give it a go. You guys are the experts with this one, so any and all opinions will be most appreciated.


----------



## Plowboy (Feb 24, 2016)

On my car it turned out to be the Driveshaft Center Support Bearing but my car has about 140k miles.


----------



## GTO44 (Apr 11, 2016)

That's without a doubt a torn carrier bearing. Exact thing happened to me a few months ago. When taking off in first gear you hear a Thump, Thump, Thump, Thump until you get over a certain rpm and it goes away.

You have 2 options. First option Buy a new carrier bearing for $89. Remove the factory driveshaft. Put it in a vice and split it, replace the carrier bearing, tap back together and put back into car. That sounds easy but most people can't get the factory 2 piece DS to separate. It's a royal pain in the ass. 

Second option, buy an aftermarket 1 piece or 2 piece Driveshaft and replace it with the factory Driveshaft. This is the option I went for and most people do. I got an aftermarket 2 piece replacement driveshaft. Most people go with a 1 piece. If you have the money go with Carbon Fiber as they don't have the vibration issues associated with a 1 piece. Aftermaret aluminum shafts are cheap and can be great. 2 draw backs can be: ringing from the rearend clunk caused by the pinion lash in the rearend that will ring thru the aluminum 1 piece like a bell. And the high speed rotational vibrations caused by the harsher pinion angles of a 1 piece. Some don't experience this at all. Some only expierence it at 120mph and up. Some experience this as low as 90mph.


----------

