gear noise after new gear install

Who installed the gears? Sounds like they were installed incorrectly. Incorrect backlash or pinion depth. I would suggest having them corrected.

Did you use gear marking compound to check the pattern?

Do you have a manual tranny? If so, are you sure it's not just the normal tranny whine in reverse?

88 Fox GT said:

Did you use gear marking compound to check the pattern?

Do you have a manual tranny? If so, are you sure it's not just the normal tranny whine in reverse?

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Manual tranny have a straight cut reverse gear that will make a bunch of noise when engaged. The faster you go, the more noise the the trans will make. Some audible noise is normal.

All those solid mounts you have only serve to channel the noise to you in the cabin.

Sounds like you have all the clearances set correctly. How much torque did it take to turn the pinion? Did you use new bearings?

I had a diff recently that made a little whining noise when on the gas going forward. Some whining when coasting. I had the pattern set to the center of the gear and the backlash set at .010".

I ended up simply tightening the pinion preload a little. More to the tighter end of the range. The noise ceased. The pinion seal can throw off the measurement.

I rarely check for noise in reverse because of all the inherent whining reverse gear makes. If reverse whining is really a problem you may want to check your coast pattern again. Find an area where you can coast in reverse with the clutch engaged then listed for the differential noise.

Hope this helps

Fox_84 said:

Yes this helps and I will try it. I wrench I had to set the preload was not very fine or critical in its measurement marks but it had its first one at 25 in. lbs. and this is where I set the preload. It does have new bearings and best I read everywhere, 25 in./lbs. is just right. Do you think I should try tightening this just a little? Maybe it is due to the spherical bearings. Maybe I am just paranoid because I expect all my work to be perfect and nothing shy of this. I will try the things you all have suggested except for taking the girdle back off again to check the pattern, just really dont want to have to do this. Any more comments??? Thanks A TON, Everyone!!!

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25-30inlbs is about what I use. I tend to stay a toward the tight side because fo the drag on the seal can throw things off.

Not to send you on a goose chase but, you should really recheck the pattern when adjusting pinion preload.

It is fine to be paranoid but step back and look at what you have done. You added what one could call solid mounts to the control arms. You are definitely going to hear things resonating through the chassis that you didn't before. I had the same noise experience when I installed my southside bars. (a LOOOONG time ago)

You are probably fine with your work. Maybe you shold compare what you hear in reverse, to a buddy's car. This should give you some perspective of what "loud" is.

Good Luck