After reading many threads over gears, i made up my mind. The phrase "dont fear the gear" resonated in my mind all along, so i decided to put the 4.10's in. A local guy that does many installs on the side put them on and i didn't notice any gear whine on my 25 mile trip back home.

My installer told me that after just one heat cycle (basically the drive home) would be sufficient and i could get on it after that if i want to. I read that the break-in is as much as 500 miles or 5 heat cycles, but my installer told me differently.


My question is, how long (heat cycles or miles) do i let them break in before i can WOT?

 

i waited 200 miles and mine are ok. you should also change the gear oil after break-in, because when the gears break in, they are actually cutting a pattern into each other and that releases metal shavings into the fluid. i am getting ready to change the fluid next week with some royal purple max-gear.

 

I left the shop side ways after I had my gears installed. They have been perfect till this day, no whine or anything.

 

You don't need to change the fluid after a few hundred miles, unless you like to waste time and money. There's a little magnet in the rear end that catches small metal particles.

No one changes diff fluid a few hundred miles after the car was new, so why do it now?

It's totally not necessary and a waste.

 

let us know how they feel down the road..
are you planning to go to the texas cruise again?

 

I think the gears finished their first heat cycle and are completely cool. Im about to take it for a spin but im still kinda confused on when i can start running it hard like i normally do lol. Also, the oil my installer used was 75w-90, is this right? i ask because other people told me 75w-140 was needed for gears.

Badstang, yeah im pretty sure i am going to the cruise since they changed the date. Should have at least 40-50 stangs again like we did last time!

 

My installer told me i could get on it right after i left the shop... and i did. No problems with mine and ive got 10k miles on em

 

I was checking into the price for install last week (I don't have gears, YET) and they said the same, that there isn't a long break in needed. He didn't seem concerned about driving it how I would want right away.

 

100% correct. And gears are run before they leave the factory and require no break-in period.

 

10 minutes after I dropped the car off the jack stands it was at WOT when I finished my gears. I think I have like 15k or so on them now and no problems at all.