Rear end whine under power- gone during coast
09-17-2018, 12:54 PM
#1
Burning Brakes
Thread Starter
Rear end whine under power- gone during coast
car was loud before so I didn’t notice. Now I hear a whine from the R.P. While cruising at steady throttle. It immediately ceases as soon as I let off the throttle. Too much clearance on Ring and pinion or pinion depth issue?
09-17-2018, 01:04 PM
#2
Le Mans Master
Member Since: Aug 2017
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I assume fluid is topped off and contains a mix of GM lube + posi lube modifier?
09-17-2018, 04:11 PM
#3
Burning Brakes
Thread Starter
09-17-2018, 04:15 PM
#4
Race Director
Did the noise start as soon as you put it together with the new ring and pinion? Because generally when you do something and something else goes wrong, you just did it. And I assume the whine doesn't go up and down with engine RPMs as you shift? Cuz that would be a trans not a rear end noise. But it sounds like you got the ring and pinion setup with the Lash incorrect.
Last edited by derekderek; 09-17-2018 at 04:16 PM.
09-17-2018, 05:58 PM
#5
Burning Brakes
Thread Starter
Definitely not the transmission. I had a loud side pipe exhaust on the car until recently, so I wouldn’t have heard it.
09-17-2018, 08:43 PM
#6
Team Owner
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St. Jude Donor '05
What brand gears are they? I agree it shouldnt make any noise but some gears esp lower ratios can.
Did it do it right after install?
Did it do it right after install?
09-17-2018, 10:55 PM
#8
Tech Contributor
Richmond are imported, not that it helps you now but you should have used Tom's. Richmond runs a looser lash, probably marked 008-010 on the gear. Did you take any pictures of your final pattern? It is possible you set them up correctly but have a bad gear set. I had a new set of the USA Richmonds, 355's, dial in perfect- pattern, lash was dead on- yet they were noisy. Some gear noise can be expected with Richmonds but this was terrible. Replaced them with Tom's 355's, same procedures only they were quiet. Again that was with the USA gears, I have not used them since. Were they 2 or 5 cut gears?
09-18-2018, 01:13 AM
#10
Team Owner
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St. Jude Donor '05
w/GTR
09-18-2018, 01:22 AM
#11
Team Owner
Like GARY said I reused my Richmond 4.11 old gear setup in a new housing I ended up with a tight lash like. 005 to. 006 and under load I have a whine. It was also me putting it together and I had the ring and posi in and out 10 times trying to get the best patterns
the other problem was I'm not a rear end pro like Gary
my US gears 3.55 never made a noise
the other problem was I'm not a rear end pro like Gary
my US gears 3.55 never made a noise
09-18-2018, 08:52 AM
#12
Burning Brakes
Thread Starter
Man, it has been a few years. I did the R. P. swap while i was doing the frame off. I am pretty sure that I sent pics to you, and based upon what you saw, it was ok, but that was like 3 phones ago. I also did the super 10 and posi set up according to your paper. 0.008" comes to mind, but all my pics are lost to technology updates.
Richmond are imported, not that it helps you now but you should have used Tom's. Richmond runs a looser lash, probably marked 008-010 on the gear. Did you take any pictures of your final pattern? It is possible you set them up correctly but have a bad gear set. I had a new set of the USA Richmonds, 355's, dial in perfect- pattern, lash was dead on- yet they were noisy. Some gear noise can be expected with Richmonds but this was terrible. Replaced them with Tom's 355's, same procedures only they were quiet. Again that was with the USA gears, I have not used them since. Were they 2 or 5 cut gears?
09-18-2018, 08:53 AM
#13
Burning Brakes
Thread Starter
I am no pro either! If i still had a loud exhaust system I wouldnt even be aware of this concern!
Like GARY said I reused my Richmond 4.11 old gear setup in a new housing I ended up with a tight lash like. 005 to. 006 and under load I have a whine. It was also me putting it together and I had the ring and posi in and out 10 times trying to get the best patterns
the other problem was I'm not a rear end pro like Gary
my US gears 3.55 never made a noise
the other problem was I'm not a rear end pro like Gary
my US gears 3.55 never made a noise
09-18-2018, 11:08 AM
#14
Tech Contributor
Sorry but I don't recall, I get 100's of emails and calls and try to answer them all but I sure can't remember them all. I don't think I would have recommended Richmond gears, ever, so you must have bought them before? I was also not here for 8-9 years so you might have reached me elsewhere?
Regardless, without pictures of the pattern or setup information I can't tell you much. If you are going to drop the diff out then install Toms gears and move forward. I doubt the issue will cause a lock up of the diff so it's a case of live with it or replace the gears.
A real super 10, not the knock off ones, will have Tom's 30 spline axles, hardened faces, fully polished and tuned posi with 10-17 x 30 heat treated spiders, ARP ring gear bolts, solid sleeve, steel cap ( only needed on the LH side), billet pinion yoke, HD cover, and USA Timkens.
Regardless, without pictures of the pattern or setup information I can't tell you much. If you are going to drop the diff out then install Toms gears and move forward. I doubt the issue will cause a lock up of the diff so it's a case of live with it or replace the gears.
A real super 10, not the knock off ones, will have Tom's 30 spline axles, hardened faces, fully polished and tuned posi with 10-17 x 30 heat treated spiders, ARP ring gear bolts, solid sleeve, steel cap ( only needed on the LH side), billet pinion yoke, HD cover, and USA Timkens.
09-18-2018, 01:02 PM
#15
Burning Brakes
Thread Starter
Gary, I wouldn’t expect you to remember every one you talk to! Also I wasn’t insinuating that you were some how responsible! You helped advis me on a few things and your reputation is impeccable! I did the springless set up and steel billet cap, bolt upgrades, polished case etc with your direction. I can tell you that I recall you had reservations about the Richmond gears for this reason, but I already had them.I was in unemployed at the time and had budget constraints ( still do!)
09-18-2018, 08:52 PM
#16
Tech Contributor
Gary, I wouldn’t expect you to remember every one you talk to! Also I wasn’t insinuating that you were some how responsible! You helped advis me on a few things and your reputation is impeccable! I did the springless set up and steel billet cap, bolt upgrades, polished case etc with your direction. I can tell you that I recall you had reservations about the Richmond gears for this reason, but I already had them.I was in unemployed at the time and had budget constraints ( still do!)
Now if you decide to replace the gears there are some positive things in your favor.
1- you now have experience working on these diff's, you know what tools you will need and have a very good feel for it. The second time around will be different. While there are issues that pop up with these from time to time you know what you have so there shouldn't be a surprise.
2- Tom's wife is still running the business and I just set up a set of new 373's that were dated April 2018 and they dialed in great, were 5 cut and there was no gear mesh noise running them in. I don't know if they were part of an order prior to Tom's passing or afterwards but they still have stock. If you can I would get a set while they still are.
3- you have used good parts and procedures. I must have gone over posi tuning with you and how to know if it's balanced and there is more involved with tuning then leaving out the springs/plates. I would replace the case and pinion bearings if you decide to replace the gears, the axle bearings are probably still good. So a good master kit would be worth it.
If you decide to do it again and want to talk it over you can always contact me and I'll be glad to help you out. I know how frustrating it is to pull it out again, I have been there as well with my 72 years ago.
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