LX Forums Forum banner
1 - 20 of 29 Posts

·
LX Newbie
Joined
·
39 Posts
Discussion Starter · #1 ·
Hi everyone.

Just picked up my Mag after having a Quaife ATB installed.
After 100 miles I picked up a rear end whine that is very noticeable at speeds above 50. The "whine" is most prevalent when applying just enough fuel to put a slight load (like holding a steady speed on a nice flat straight road).

Anyone have a similar experience?

I will head back to the speed shop in the AM but I though I listen here for any words of wisdom as I don't believe this should happen at all.

Thanks.
Phil
 

·
Premium Member
Joined
·
16,581 Posts
no whine from mine..

What Model Magnum do you have?

When you 1st drove it did you drive it easy for a while so the gear lube could heat up before you beat on it?

How much waas your install?
 

·
Great White Shark
Joined
·
122 Posts
What fnkychkn posted:

fnkychkn said:
gear whine during float (between accel & coast) is caused by incorrect gear contact pattern. since i doubt they moved the pinion gear to install the quaife diff, i'd bet the ring gear backlash is incorrect and will need to be readjusted.
What I understood:

fnkychkn said:
blah blah blah blah (between blah & blah) is caused by incorrect blah blah blah. since i doubt they moved the blah blah to install the blah blah, i'd bet the blah blah blah is incorrect and will need to be readjusted.
This happens to me often when I read the more technical posts in this forum. I have nothing useful to add, other than, I hope fnkychkn has it nailed, and that you can get it resolved easily and cheaply (if not for free). :)
 

·
Registered
Joined
·
44 Posts
agree with fnkychkn I would guess bearing preload was set incorrectly then after a few miles of breakin wear of the new bearings allowed the backlash to exceed specs.The Quaife should be perfectly fine only negative maybe the wear on the ring and pinion may not be able to be adjusted to get rid of the whine without replacement. Drive the car sparingly and very gently.
 

·
What'd I miss?
Joined
·
23,444 Posts
daffin said:
What fnkychkn posted:

What I understood:

This happens to me often when I read the more technical posts in this forum. I have nothing useful to add, other than, I hope fnkychkn has it nailed, and that you can get it resolved easily and cheaply (if not for free). :)
LOL. not sure how i could make it any easier to understand, but i'll try.

the pinion gear is splined to the input yoke of the rear axle assembly and rotates with the propshaft. the ring gear is meshed at 90 degrees to the pinion gear and transfers torque from lengthwise (propshaft) to crosswise (axle shafts). these two gears must mesh precicely in order to prevent gear noise. if either gear is not in proper position, gear noise will result.

hope this is easier to understand. :blah:
 

·
LX Newbie
Joined
·
39 Posts
Discussion Starter · #8 ·
fnkychkn said:
LOL. not sure how i could make it any easier to understand, but i'll try.

the pinion gear is splined to the input yoke of the rear axle assembly and rotates with the propshaft. the ring gear is meshed at 90 degrees to the pinion gear and transfers torque from lengthwise (propshaft) to crosswise (axle shafts). these two gears must mesh precicely in order to prevent gear noise. if either gear is not in proper position, gear noise will result.

hope this is easier to understand. :blah:
Sure is and thank you. I guess the question is with 100 miles will they be able to adjust the backlash or am I going to be "down" while we wait for a new ring and pinion? Also, I was told "sythetic oil" plus a posi additive was used. I explained, that this is a clutchless system. While I have no hope that the whine is due to the lubricant I did print out the "specs" from Quaife for them to review in the AM.

Thanks again.
Phil
 

·
Great White Shark
Joined
·
122 Posts
Thanks for the additional explanation! I didn't intend to take you to task over being "too technical"--rather, I was complaining about my own ignorance. I was never the "car guy" in my family, that's always been my brother. :)
 

·
LX Newbie
Joined
·
39 Posts
Discussion Starter · #12 ·
fnkychkn said:
gearset should be OK. probably just out of adjustment.
As I ruminate over this I can't help but ask the question... Do you know what the backlash should be? And most importantly, does the Quaife have to come out along with all the suspension again to adjust this?

As I recall, the dealer said the unit arrived w/o any instructions - alarms should have gone off but I was asleep at the wheel.

Thanks again.
Phil
 

·
LX Newbie
Joined
·
39 Posts
Discussion Starter · #16 ·
ring gear backlash ... the plot loosens

fnkychkn said:
ring gear backlash should be 0.004"-0.006".
Well the plot loosens..

The backlash pre install was .006 post install was .008

Both shop owner and one of the engineers at Qualfie of America claim backlash spec to be .004 to .010. Shims are only available in .002 increments. Both shop owner and engineers at Qualfie claim that the noise would only move (in terms of speed) as getting things back to .006 may be difficult. Furthermore, since the carrier for the pinion is now milled versus cast steel the harmonics have changed. Both further stated that since the backlash was within spec (.004 to .010 albeit on the loose side ) that nothing would be gained (sans the noise reduction). Now mind you the noise is only noticeable at 51-52 mph.

Labor was 5 hours @ $85.00 / hr. During the installation a lower control arm was broken. The install is about as fussy as installing headers. Basically the install is a pain in the butt.

At this point I'm going to put some miles on the car and see what happens although your statement of what the spec is has me a tad concerned.

FWIW, the unit functions seamlessly. Hole shots are more controlled. Wet roads - pre install the car was totally useless on wet roads; always invoking TC. Post install the car is manageable but one still has to be at the top of their game if you are putting your foot into it (on wet pavement that is).

Is that spec (.004 to .006) in print anywhere?

Thanks to everyone.

Phil
 

·
Premium Member
Joined
·
7,000 Posts
I had an RX8 that had that whine, under light load, between 67 and 68 mph. Did it for 30K and the Dealer said it was a "normal" noise.
It also had a limited slip diff with the same ideas as the Quaife (it was a Torsen diff... same idea, different manufacture...) came stock with the car...
 

·
What'd I miss?
Joined
·
23,444 Posts
LilTank said:
Well the plot loosens..

The backlash pre install was .006 post install was .008

Both shop owner and one of the engineers at Qualfie of America claim backlash spec to be .004 to .010. Shims are only available in .002 increments. Both shop owner and engineers at Qualfie claim that the noise would only move (in terms of speed) as getting things back to .006 may be difficult. Furthermore, since the carrier for the pinion is now milled versus cast steel the harmonics have changed. Both further stated that since the backlash was within spec (.004 to .010 albeit on the loose side ) that nothing would be gained (sans the noise reduction). Now mind you the noise is only noticeable at 51-52 mph.

Labor was 5 hours @ $85.00 / hr. During the installation a lower control arm was broken. The install is about as fussy as installing headers. Basically the install is a pain in the butt.

At this point I'm going to put some miles on the car and see what happens although your statement of what the spec is has me a tad concerned.

FWIW, the unit functions seamlessly. Hole shots are more controlled. Wet roads - pre install the car was totally useless on wet roads; always invoking TC. Post install the car is manageable but one still has to be at the top of their game if you are putting your foot into it (on wet pavement that is).

Is that spec (.004 to .006) in print anywhere?

Thanks to everyone.

Phil
0.010" is too loose. did they check gear contact pattern?
sent you an e-mail with specs
 

·
What'd I miss?
Joined
·
23,444 Posts
lafrad said:
I had an RX8 that had that whine, under light load, between 67 and 68 mph. Did it for 30K and the Dealer said it was a "normal" noise.
It also had a limited slip diff with the same ideas as the Quaife (it was a Torsen diff... same idea, different manufacture...) came stock with the car...
doesn't matter if limited slip or not. diff design will not affect gear noise. only gear contact will affect gear noise.
 

·
LX Newbie
Joined
·
39 Posts
Discussion Starter · #20 ·
Backlash Redux

fnkychkn said:
0.010" is too loose. did they check gear contact pattern?
sent you an e-mail with specs
Just to clarify, the post install backlash is .008 not .010. Pre install it was .006

No, no one checked the gear pattern and I feel like I'm stuck here.

Quaife and The Local Speed shop are in agreement. Now it is like bucking City Hall. In the end BOTH just are sticking to "nothing to worry about, go have fun". Well maybe they are right and I'm making a BIG deal over a very small thing. However, if the rear end blows only I will be paying.

I seached through the shop manual and could not find ANY specs for backlash for any rear end or any reference to the axle ratio of 3.06. Rather odd.

I did respond to your email. Thank you.

One thing is for sure - this forum is the TENS!

Thanks again to everyone, with extra thanks to fnkychkn.

Phil
 
1 - 20 of 29 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top