Is my drive shaft rear CV joint bad?

I'm chasing down a gear whine type noise in my drivetrain that happens between 40-60 mph but it only happens when the drivetrain barely has a load applied to it.

Whine will come in for a split second when letting off the throttle to shift from 4th to 5th right when the drivetrain goes from loaded to unloaded. If your cruising along in 5th and just barley giving it throttle, like 15% throttle angle I get whine. The second more throttle is given or I let off the throttle he whine goes away. If I push the clutch in whine goes away. Rear end backlash, preload and all that stuff have been checked and double checked.

Was under the car this weekend trying to figure out what's causing this and think my whine might be the drive shaft rear CV joint. The CV joint feels loose and when I grab the end and push on it I can get it to move back and forth around 1/16", uploaded a youtube vid showing the movement.

I'm not a CV joint expert but does this joint seem bad to yall?

Edit: You can hear the clicking/movement if you have sound on.

I doubt it's your drive shaft, the stock 8.8 is just stupid loud for some reason and some are worse than others. You possibly have a failing pinion bearing.

2011 gtcs said:

I doubt it's your drive shaft, the stock 8.8 is just stupid loud for some reason and some are worse than others. You possibly have a failing pinion bearing.

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Same issue- warranty fix was new pinion bearing

Blkblk13car said:

Same issue- warranty fix was new pinion bearing

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Gotcha, I just haven't seen a lot of the CF driveshafts have issues. Sucks they're so much money

Damn, I thought maybe I had found the issue.

If that’s the case then this really opens up a can of worms. Factory 3.73 had the “normal” whine most complain about and it wasn’t bad by my standards. The rear had 40k miles on it so I figured why not rebuild it with new bearings and 3.55’s so my street tires had a fighting chance at getting traction. Ever since the rebuild I’ve been fighting this light throttle whine issue and this whine is so loud it makes the “normal” 3.73 whine seem like nothing. I know the most logical path is it’s the rebuild with 3.55’s. The shop I used knows what they are doing and have taken the rear apart a couple times and verified backlash, reload, wear patterns and everything is to spec. So either the shop is not doing something right, awkward. Or my car just doesn’t like 3.55’s and the harmonics are just right to create an ungodly gear whine. Man I really wanted to avoid another rear end rebuild.

merkyworks said:

Well heck, I thought maybe I had found the issue.

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I'm not saying the driveshaft couldn't be the issue, it would be nice if you knew another local 13/14 GT500 guy that could swap driveshafts with you, just to verify if that fixes it.

2011 gtcs said:

I'm not saying the driveshaft couldn't be the issue, it would be nice if you knew another local 13/14 GT500 guy that could swap driveshafts with you, just to verify if that fixes it.

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Yeah I wish I did as well. Was toying with the idea buying a new DS but with the pinion bearing comments I’m not sure now. I figured the movement of that CV joint was a smoking gun and most would say that’s the issue.

merkyworks said:

Yeah I wish I did as well. Was toying with the idea buying a new DS but with the pinion bearing comments I’m not sure now. I figured the movement of that CV joint was a smoking gun and most would say that’s the issue.

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The CV joint is ment to move a little, but it's hard to say what's within spec.

merkyworks said:

I'm chasing down a gear whine type noise in my drivetrain that happens between 40-60 mph but it only happens when the drivetrain barely has a load applied to it.

Whine will come in for a split second when letting off the throttle to shift from 4th to 5th right when the drivetrain goes from loaded to unloaded. If your cruising along in 5th and just barley giving it throttle, like 15% throttle angle I get whine. The second more throttle is given or I let off the throttle he whine goes away. If I push the clutch in whine goes away. Rear end backlash, preload and all that stuff have been checked and double checked.

Was under the car this weekend trying to figure out what's causing this and think my whine might be the drive shaft rear CV joint. The CV joint feels loose and when I grab the end and push on it I can get it to move back and forth around 1/16", uploaded a youtube vid showing the movement.

I'm not a CV joint expert but does this joint seem bad to yall?

Edit: You can hear the clicking/movement if you have sound on.

Click to expand...

Mine started whining about 500 miles after I put drag radials on. It was silent before that. Im about to go with a set of ford racing 4.10’s as soon as my preferred shop can get to it. This is about the only work I will not do myself. I will let you know how it does. This is my first gear swap on the GT500, but everyone says its in the install/set up. If it whines from the jump, something wasnt installed or set up correctly. Again, thats just what I read and hear. Please post if you fiquire it out.

My CV joint has the same “click” and slight movement as well, but it did before it whined too, so its probably as 2011 gtcs said on that issue...