it needs to be done with just the carrige and pinion in, no axles going to the wheels. it can be done on car, you just need to know what your doing. Look through the guide and you can see it in one of his pics.

 

There should be zero noise when done with a install. It is possible the the cut on the gears are the noise concern. However the pinion preload should be check also. The bad thing is that the whole diff needs to come apart for that. If it makes noise when first driven it will probably make noise at 500 miles and so on.

 

dammit, so in order to tighten it I would HAVE to take out the axles, diff, ring gear.....??
that sucks...

 

if the carrier load is not set right or just in general?

 

i called the shop that did the install today and they couldnt tell me right away what they spec'd the backlash to (they brought in an "outside guy" to do the install) but the tech said he would talk to the shop manager and see what he says about the backlash/carrier load and he mentioned something about adjusting the pinion angle as well.

 

dude I feel your pain!!!!!!!!! I have been through a gear nightmare install myself, backlash measures the distance away from the ring gear to the pinion gear. I think that is adjusted by shims. what I didn't get how to adjust is the pinion depth, somone should chime in and tell me how that is done,

so there is 3 adjustments someone correct me if I am wrong, backlash, pinion depth and pinion bearing pre load.

the dealer put 3 different gear sets in my rear end, still whined, got way way worse after putting in BMR LCA's took the car to another shop they put in US gear 3.73 gears, these were aweful and the worst so far, I bought a complete rear diff from new take off, I have a slight whine from 65mph to about 75mph, no whine anywhere else, which is nearly exactly what the final dealer installed gearset did although this one is quieter. so I am just running the factory LCA's and have just been dealing with a slight whine, I may change out the fluid to the heavier 85-140w gear lube, as when the diff is cold it is very quite no noise. I am also wondering if because the whine was basically the same with this diff and the last dealer installed gear set if the whine is coming from somewhere else. in any event its tolerable.

it is also my opinion that whatever noise you have the moment you take your very first drive is the same noise you will have after breakin or whatever miles you care to put on it. I also wonder why when the factory installs gears they don't need a breakin but when they are installed after the fact supposedly they need breakin. I think that is kinda hokey in none of the installs did the whining ever get better or worse with more miles. you got what you got.

I also wonder as most likely most installers may be going wrong with not enough pressure or pinion preload. I am wondering if this is the case why it would hurt if you just tightened that down more and brought that into spec after the fact.

 

they need a break in time in that you do not want to go too hard to soon on them or you can cause premature wear and a gear that will fail far before its do. They want you to get them good and warn so they dont make noise and have to go back in. They dont care if start sheering teeth off 3 years from now.

 

It's been my experience that even the most "experienced" guys out there (at least in my neck of the woods) all have different opinions on break-in, gear whine, etc.... Some guys will tell you that some gears just make noise and other guys will tell you that they shouldn't. I was told to stay away from Motive gears because they make noise (whine) so I went with the FRPP (Ford Racing), only to find out that Motive started making the FRPP gears years ago..... Oh well, I can hear mine but it's very faint so I'm not worried about it.

 

If there is noise, it wont go away. What you hear out the door is what you get. Royal purple synthetic gear oil comes with friction modifier, but have you ever checked with your installer what type of oil was used and if friction modifier was involved?

 

heres a question to all you guys that took it back to the shop to have the whine fixed: did you have to pay at all for the adjustment (labor? new oil? new crush sleeves/bearings or shims/seals?)?