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Discussion Starter #1
I got FRPP 3.73s installed a few weeks back. At first, there was NO noise at all from the install.
But within the last week, I have noticed the whine coming, with today being the most noticeable.

It typically occurs during decel around 45 and slower, after cruising at above 45. If i decel in gear mostly. Then it will continue until i accelerate again. Does not do it at cruising speed above 60, etc.

I am not familiar at all with the intricasies of gear installs, backlash, etc.

I had the gears installed with royal purple and 2 bottles of friction modifier. I assume they used the friction modifier... but dont know for sure.

As I said, at first they made zero noise.

Any ideas of why?
 

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Maybe pinion nut preload was not properly set. There is a crush sleeve that puts pressure on the pinion bearing which allows the installer to set preload. These have been know to crush a little further and change the setting. Rears set up for serious race application use solid sleeves to prevent this from happening. One of the pinion setting procedures is to use a inch pound torque wrench to measure the rotational force as you set the nut. I wonder how many shops do this? I think many installers just set the nut torque. Did the noise show up after some hard driving/launches.(this may of crushed the sleeve a bit further) If the preload was too loose it would allow the pinion gear to move and cause noise, among other things. The shims must be right since it was quiet at first. The friction modifier is mostly for the clutches I think.
 

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Discussion Starter #3
Good questions...
Ill have to ask the shop. If this is the case, how would I make the argument to the shop?

The gears were super quiet at first, with no whine at all. IT only does it between 20-40mph, and does it on accel as well.

I didnt launch it hard at all, but I did do a few hard take-offs. I also only had maybe a few highway blasts. Nothing that should have been remotely hard on the rear-end.
 

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Maybe just ask the shop who installed the gears why they think there is noise. Having a little knowledge about the procedure would help you understand what they are talking about. Check out some you tube videos on installing 8.8 gears. Since it was quiet at first leads me to think something about gear pattern changed or the gears have damage. I would think a bearing noise would produce more consistant noise. I have FRPP 3:73 gears in my auto GT and they are quiet. Good luck!
 

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i would definitely pull the cover and inspect , measure
back lash. this way you can recheck and torque everything.Oil is cheaper than having to rebuild a destroyed rear end.
 

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Discussion Starter #7
Update - the gear whine is still there, only making noise between 20-45 mph, but there during acceleration and decel.

Hasnt gotten any worse.

Shop isnt covering it since they were used gears, but the wear pattern was perfect and the whine didnt start until about 200 miles or more after the install....
 

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Update - the gear whine is still there, only making noise between 20-45 mph, but there during acceleration and decel.

Hasnt gotten any worse.

Shop isnt covering it since they were used gears, but the wear pattern was perfect and the whine didnt start until about 200 miles or more after the install....
Lol, Wait, Why is this the first mention of them being used? Doesn't matter if the wear pattern was perfect for someone else's car, they have a wear pattern, they're worn.
 

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So i just installed 430s brand new and im getting tip in whine/howl at 70mph. I have about 100 miles on it can i re adjust to stop the whining? Or will it always be there now?

---------- Post added at 08:35 AM ---------- Previous post was at 08:33 AM ----------

Okay bearing preload on the pinion is 21inlbs.. Backlash is at .010..used a .028 shim for pinion..
 

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So i just installed 430s brand new and im getting tip in whine/howl at 70mph. I have about 100 miles on it can i re adjust to stop the whining? Or will it always be there now?

---------- Post added at 08:35 AM ---------- Previous post was at 08:33 AM ----------

Okay bearing preload on the pinion is 21inlbs.. Backlash is at .010..used a .028 shim for pinion..
You can try to reset the gears properly, but they will most likely continue to whine now that you've drove 100 miles with them.

I installed my new FRPP 3.73s by myself and they whine exactly how the OP said his does. I fixed mine by making the exhaust louder. It's hard to find someone that can install gears with no whine at all, that's why I did mine myself. I did mine by the book and used paint to check the wear pattern, but it still whines.
 

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Discussion Starter #11
Lol, Wait, Why is this the first mention of them being used? Doesn't matter if the wear pattern was perfect for someone else's car, they have a wear pattern, they're worn.
I have used gears in the past, and ive never had gear whine. Worn gears doesn't necessarily mean whiney gears.
Being worn wouldn't guarantee that they are going to whine unless they were setup and worn wrong to begin with - leading to immediate whine upon install.

This is why i mentioned that they didn't whine until at least 200 miles after install. The wear pattern would have been set in around 50-100 miles, but since they didnt start making noise until so long after the install, im wondering why...

---------- Post added at 04:19 PM ---------- Previous post was at 04:17 PM ----------

Is this problem as common with 4.10 as it is with 3.73s. It seems VERY common with 3.73s.
 

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Doesn't necessarily mean it will have issues but it's an easy explanation as to why they are. Shop won't warranty it because it is a distinct possibility of having noise even on a perfectly worn set of gears.

I have heard so many hit and miss stories on gears I went with my most trusted brand on my last set. Richmond Gears has done me well for 30 yrs and did me well again so that is who I would recommmend for gears if you're gonna buy new ones.
 

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Doesn't necessarily mean it will have issues but it's an easy explanation as to why they are. Shop won't warranty it because it is a distinct possibility of having noise even on a perfectly worn set of gears.

I have heard so many hit and miss stories on gears I went with my most trusted brand on my last set. Richmond Gears has done me well for 30 yrs and did me well again so that is who I would recommmend for gears if you're gonna buy new ones.
what do you think about my earlier post?
 

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Discussion Starter #14
Doesn't necessarily mean it will have issues but it's an easy explanation as to why they are. Shop won't warranty it because it is a distinct possibility of having noise even on a perfectly worn set of gears.

I have heard so many hit and miss stories on gears I went with my most trusted brand on my last set. Richmond Gears has done me well for 30 yrs and did me well again so that is who I would recommmend for gears if you're gonna buy new ones.
What, if any, reason would there be a distinct improvement between richmond and frpp?

If richmond doesnt whine, what would cause FRPP to be so problematic?
 

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Not an engineer and maybe it's just luck, but I never had an issue with them. 30+ years putting together cars and used many different brands of products and I just gravitate to what I've had success with.

---------- Post added at 10:07 PM ---------- Previous post was at 09:33 PM ----------

what do you think about my earlier post?
Sounds like it is all within spec. In my experience the higher the gear ratio the tighter we tended to set the backlash. Just always seemed to work out that way. You are on the tighter side already but it you went down a couple more thousandths it might help. Have you ever checked for runout on the ring gear? Seen that outa whack before.
 

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You didn't install any other rear suspension parts and then notice more whine? Or maybe have the rear seat up at first and then have it lowered. Silly questions but they might explain the increase in whine noise. Anytime a shop installs your used parts I would say warranty is non existant.
 

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Not an engineer and maybe it's just luck, but I never had an issue with them. 30+ years putting together cars and used many different brands of products and I just gravitate to what I've had success with.

---------- Post added at 10:07 PM ---------- Previous post was at 09:33 PM ----------



Sounds like it is all within spec. In my experience the higher the gear ratio the tighter we tended to set the backlash. Just always seemed to work out that way. You are on the tighter side already but it you went down a couple more thousandths it might help. Have you ever checked for runout on the ring gear? Seen that outa whack before.


Ill check it. Can i make it not whine now that it already has tho? I saw the pattern is starting to set it makes me nervous lol.

---------- Post added at 07:40 PM ---------- Previous post was at 06:45 PM ----------

Only .001 runout.
 

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Discussion Starter #18
I was lowered before but still have factory control arms. Sound wasnt there for the first 200 miles of driving after the install.

Ive been reading and noticed that in 2010-2012, the rebuild kits used an upgraded high-tq pinion bearing.
I used a rebuild kit that wasnt a frpp one.

Im wondering that if after a couple hundred miles, the standard bearing may have shifted and caused the gear to be a little off adjustment?

This seems to be a theory with the gt500 guys.

Im assuming the rear end in the gt500 and gt is the exact same and no difference, correct?
 
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