I put them in today, and all I can say is wow. The car just feels so much better. Now I have to endure the torture of not really getting on it for a few hundred miles.
I was told to be somewhat easy on her for the first 50-100 miles by not doing any burnouts or WOT shifting. Now I have over 2000 miles with the 4.10s and absolutely no issues.
I have my 4.30's sitting next to me in my office right now..... I am waiting to get them installed. Man, I can't wait! And I heard that the proper break in period is 500 miles. Thoughts?
500 miles is a pretty good rule of thumb. The important thing is to let the gears go through several complete heat cycles. Meaning getting them warmed up, and letting them cool off completely.
So the rear end housings get several heat cycles on them before they are installed in the cars before they are shipped out to the dealer? I was told by a reputable speedshop that specializes in Mustangs, that only about 50-100 miles of normal(i.e. sensible) driving was all that was required.
Hey Hotty, what brand did you get?? Ive put about a hundred miles on them and so far so good. They whine some but my exhaust is so loud that I can barely hear it at most speeds. I pulled the fill plug yesterday and so far no metal pieces, yay!!
I have heard all different miles for break ins, but what I have always done is 10 heat cycles and close to 100 miles. My installer told me it is all in the installation, but I still went a total of 10 heat cycles.
I have over 4000 miles on my 4.10s and have absolutely no whine or clunking from the rear diff whatsoever. I took it easy for the first 100 miles.
I got the FRPP gears. I will be installing shortly *crosses fingers*. And your gears shouldn't whine at all. It is all in the installation (regarding the whine). If the shop was reputable, then I would take it back. You shouldn't have to drown out the noise with your exhaust noise....although a little exhaust noise never hurt anybody.....
I dont have to drown out the noise, it really isn't that loud. And as a lot of people have found, the gears with step cuts on the back of the ring gears i.e motive (FRPP), pro 5.0 and others will wine some no matter how perfect the pinion depth or the backlash is. I wou ld have gotten motorsport gears but ford doesn't make a 4.30, the only ones I have ever seen from ford were made by motive, hense the M on the end of the part number. I installed them myself and I made sure everything was as perfect as it could be.
gear whine is not normal. period. it means there is too much friction, or improper settings in the install.
+1 for gear whine not normal, and as far as break-in time the gears are already tempered, and on a good install not really necessary, but it doesn't hurt either i guess.
+1 i got the 4.10s in and went right at it, no whine, no problems. loved it but now i am itching for more, hahaha. damn mod bug is not imaginary. its the real $#!t Hey RhinoGT, did you use the friction modifier? i hope you did.
Put mine in and went right out on the street and test beat the damn things immediately.. No break in for me.. Break for me is my burnout thats done just outside of the garage. I guess it could be called the first heat cycle.. lol
You should've heat cycled a brand new set of street slicks at the same time as the gears...2 birds with 1 stone
I went easy for about 300 miles and certainly no track use. They have made the car less user-friendly as a daily. With my street Nitto DRs, the effective gear ratio is 4.3. Yours might actually be closer to 4.4 with your tire diameter of about 26.66 if you have 275/40/18, unless my math is off.
