Well after a longgggg a$$ day, I can finally say my 4.10s are in and out of the box in my trunk. Well my day started out pretty ****ty when I ended up taking the long way to real speed auto. in Long Island, but only got worse. The day couldnt get any worse until they finished it up and took it out for a test run and had to have it towed back to the shop, cause he felt something dragging in the rear and didnt wanna cause potential damage. Turned out I shouldve listened in the first place and just replaced the bearings even with 7k miles. They tore everything back apart and I was there for another 3 hours while they installed the new bearings and put it back together. The bearings and oil etc. cost me $200, but the guys at realspeed were nice enough to wave the re-install fee and the charge for the first oil that was in the car for about 1 mile. All together it cost me $475 with the bearings and for and install and than a re-install I guess you can say lol, but the ****ty part was, I dropped the car off at 11 and it was finally finished at 6 =[. They were extremely nice there and I have no whine what so ever, and they even gave me a free tshirt. I would recommend them to anyone.

 

WOOOO HOOO lol how's it feel to drive?

 

Feels great lol. The car actually spins second if you punch it, and just seems a whole lot quicker. I havnt really gotten on it as they told me to let the bearing break in for about 200 - 300 miles so I only played around a little but it is absolutely the best mod so far. Only complaint I have is that at about 70 mph im at 2500 - 2600 rpm =/. I averaged 27.7 mpg going there with 3.31's and 22.0 comming home with 4.10s. But in town I now have a 16.8 avg whereas it used to be 12.8. But who buys a mustang for the gas mileage =P

 

Actually 500mi. is the recommended break in period.

 

Glad I know that now. Thanks man!

 

Well you got lucky, they could have charged you a double install fee for sure. New bearings, yeah thats a must. Glad they got it back together and its working good. And like you stated, forget the gas milage BS, its a mustang, a muscle car built for power and rubber burning fun! Just fill with premium and dont look back, leave the nickel and dime attitude for guys with hybrids!!

 

Awesome. I have them as well and couldnt be happier. As for the break in period when i asked brenspeed about that 500 mile break in period they said there was no break in period. However my drive back home is about 125 miles so when i went home i took it easy. But i certainly didnt wait until 500 miles and i had no problems. Im sure there will be alot of people that will disagree I was just letting u know what a reputable speed shop says. So enjoy the newly found power

 

Just drive slower on the highway! I've always heard with gears you get worse on the highway, better in the city.

 

The most important thing is a couple of good heat cycles. When the gears are breaking in extra heat is generated. A couple of 20-30 minute drives with complete cool down inbetween will ensure a long life for the gears.

It sounds like you found a good shop. Sometimes that's hard to do. Maybe you should thank JDM for helping you find a good shop.

 

It appears that you are not following their advice...
And when they told you to let the 'bearing break in',
what exactly did you interpret that to mean exactly?
Bearings need no 'breaking in'.
The ring gear teeth need to 'break in' to the pinion teeth if
anything. How knowlegable are these gear installers anyhow?
This makes me leary as to the formation of the rear end whine
in your near future. You dont even mention the brand of
gears or the maker of the new bearings and seals used.
Tawain overseas or quality USA made components?