Diff whine at 40 - 50 mph - advice help please
Thread Starter
Instructor
Joined: Mar 2020
Posts: 118
Likes: 15
From: Texas
Diff whine at 40 - 50 mph - advice help please
I hope everyone is doing well.
I have a 71 - I upgraded my rear diff to 3.73 gears. The entire rear suspension has been redone, new U joints - added a TREMEC TKO 5spd, new balanced driveshaft, upgraded to 340lb monospring, new rubber, Bilstien shocks etc. The rear diff has now been pulled and shimmed three times. I added two bottles of GM posi fluid and filled with Lucas oil.
The whine has gotten a little better but I am still getting a noticeable whine between 40 mph and 50 mph and that is even after I have laid dynamat all throught the inside of the tub. It is really irritating after all the work. So.....thoughts on what to do next.
I have a 71 - I upgraded my rear diff to 3.73 gears. The entire rear suspension has been redone, new U joints - added a TREMEC TKO 5spd, new balanced driveshaft, upgraded to 340lb monospring, new rubber, Bilstien shocks etc. The rear diff has now been pulled and shimmed three times. I added two bottles of GM posi fluid and filled with Lucas oil.
The whine has gotten a little better but I am still getting a noticeable whine between 40 mph and 50 mph and that is even after I have laid dynamat all throught the inside of the tub. It is really irritating after all the work. So.....thoughts on what to do next.
Tech Contributor
Joined: Aug 1999
Posts: 15,176
Likes: 3,991
From: Connecticut, USA
what brand of gears, what is the preload and lash- are you rebuilding it or using someone? 3 attempts at shimming is a red flag need more information. Do you have pictures of the final pattern on both drive and coast?
Thread Starter
Instructor
Joined: Mar 2020
Posts: 118
Likes: 15
From: Texas
Thread Starter
Instructor
Joined: Mar 2020
Posts: 118
Likes: 15
From: Texas
Thanks for coming back to me. Not going to offer much help here for your very sensible and fair questions. I just went through my paperwork and I dont have the brand of the gear manufacturer. I did not do the rebuild. I paid for it. The other two pulls and re-shims were done under warranty - so I have only paid once. Dont have any pcitures of the wear pattern. I am almost to the point of just purchasing another rebuilt one from CorvetteMods or something along those lines. This seems like a throwing money away but its annoying the heck out of me.
Race Director
Joined: Nov 2006
Posts: 13,258
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From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
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Cruise-In VIII Veteran
That was the first thing I thought as well.Really?
Perhaps the OP needs to read some of the reviews.
Melting Slicks
Joined: Nov 2006
Posts: 3,415
Likes: 1,824
From: Apple Valley, MN
If you are willing to tackle it yourself, you can reach out to member leigh1322. He is offering up a means to obtain all the tools you need to do the job yourself. Gary (gtr1999) is the resident differential whisperer and is extremely helpful with guidance on how to do this correctly. If you want the job done right, you can do it yourself or you can reach out to Gary and see what his backlog is. Will cost you about $125-150 to ship it to Connecticut.
I did mine with Gary’s guidance and could not be happier.
I did mine with Gary’s guidance and could not be happier.
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Melting Slicks
Joined: Jul 2010
Posts: 3,176
Likes: 633
From: perth western australia
I'm sorry but you have chosen unwisely with the first attempt.
If you don't want to tackle it and my thoughts are definitely don't give it back to THEM. Take it out and mail It to Gary , you wont be sorry . It will come back better than new .
If you don't want to tackle it and my thoughts are definitely don't give it back to THEM. Take it out and mail It to Gary , you wont be sorry . It will come back better than new .
Thread Starter
Instructor
Joined: Mar 2020
Posts: 118
Likes: 15
From: Texas
If you are willing to tackle it yourself, you can reach out to member leigh1322. He is offering up a means to obtain all the tools you need to do the job yourself. Gary (gtr1999) is the resident differential whisperer and is extremely helpful with guidance on how to do this correctly. If you want the job done right, you can do it yourself or you can reach out to Gary and see what his backlog is. Will cost you about $125-150 to ship it to Connecticut.
I did mine with Gary’s guidance and could not be happier.
I did mine with Gary’s guidance and could not be happier.
