the reason why i asked if they were whistling (whining) instead of whirring, was when i had a R&P swap done in my mustang, they whined/whistled....the installer (ford dealership) immediately said "bad gears...gears are no good".....

they requisitioned another set from the parts dept, swapped 'em and no noise.

disclaimer: i assume they were "installed" correctly both times.

 

[QUOTE]Originally posted by marcucci
I did the install. The oil change is intended to identify if there is excessive wear, i.e. any shrapnel on the drain plug. This will obviously indicate an installation problem.

 

That is a thought. I removed it entirely from the mounts, I have found it is much faster that way. I am pretty certain it wasn't touching anything, and all those bolts are torqued to spec, but will inspect.

FWIW, I know in domestic circles that backlash specs of .010" or .012" (instead of .002-.004") are commonplace, and ratios in the range of 4.77 can be whiny at those clearances. I'll be very specific if this gets torn down in identifying the backlash and wear pattern.

 

I'll be checking things out in my diff soon just to inspect the wear and check to see if the backlash has changed since I've logged about 6k miles on the diff that includes a few hwy/street miles and about 10 track/auto-x events. I'm on the fence on replacing the torsen type diff to a clutch pack and getting the comptech housing. Who knows. I'll post to update if backlash has changed at all.

 

Adam,

Any updates? Is the noise getting quieter?

 

Gernby,

Unfortunately, no. And you're welcome to come hear it for yourself if you like. Just let me know.

 

Your backlash is too tight. The honda specs should not be adheared to when installing the 4.77s. Some how, somebody has to find the Mazda recomended specs for these gears because the specs for the 4.1 is just too tight. Other than that, sorry dude, but you will have to remove the diff and dial in a couple thousandths more backlash and test it out.... maybe repeat and test again. It's obvious by the physical size of the gearset alone that they should not share the 4.1 specs.

It's a shame that no backlash specs were provided with these gears. Rick seems to have learned his lesson. Notice how he's making it very apparent what the backlash is for the 4.57s.

Good luck.

 

I haven't noticed that. What are the new specs?

 

It's all over the general interest forum. the Richmond gears are to be set with .008 backlash. To put that in perspective, the Honda 4.1 gears require .0035-.0045 with a max of .007 at any of the four points on the gear.

So, basically they are going to be noisier than stock... at least until they get warmed up.

 

That sounds backwards to me (small backlash = more noise, large backlash = less noise).