Even the guys I work with, some of which have 30+ years experience in the axle business say you should ALWAYS take it easy for a minimum of 200 before you hammer on a new set of gears.
This write-up specifically calls for heat cycling...
"Next, for the first 100 miles you should drive 15-20 mile increments under 60mph and then let the differential set and cool for at least 15-20 minutes."
Didn't you say there is no such thing? I'll concede on the break-in if you're willing to give me the heat cycling.
I think this issue is more of a "what school of thought" you belong to. Neither is wrong, but one is definitely more careful than the other. That being said, I've had my gears in for 2+ years (23,000 miles) and have zero issues with them. I know I've stated that they make a little noise at certain speeds, but it hasn't gotten any worse since day one, and that small amount of NVH is more than likely not going to blow my rear end apart.
And now that I think about it, I probably drove about 150 or so miles before I really let into it. I drove back and forth to work atleast 2 days (27 miles each way) plus some errand running, so maybe I unwittingly broke my gears in.
[QUOTE='01 Steed]
Didn't you say there is no such thing? I'll concede on the break-in if you're willing to give me the heat cycling.
[/QUOTE]
Gears are heat treated to almost 1700* and then quenched in a bath of oil in a hydraulic press that shapes them and brings them to size. After that they are brought back up to 350* and then cooled. After that they are lapped to set a pattern for them to "ride" on.
"Heat Cycles" aren't going to do anything to them. They've already been hardened and lapped.
Gears are heat treated to almost 1700* and then quenched in a bath of oil in a hydraulic press that shapes them and brings them to size. After that they are brought back up to 350* and then cooled. After that they are lapped to set a pattern for them to "ride" on.
"Heat Cycles" aren't going to do anything to them. They've already been hardened and lapped.
Okay, so was it a waste of my time reading that article? I don't think so. I think the "heat cycling" in the car is bringing the two gears into sync with each other. What you're referring to is how each individual gear is made. What this is referring to is the way the two gears "get along with each other". I think these are two very different things.
[QUOTE='01 Steed]Okay, so was it a waste of my time reading that article? I don't think so. I think the "heat cycling" in the car is bringing the two gears into sync with each other. What you're referring to is how each individual gear is made. What this is referring to is the way the two gears "get along with each other". I think these are two very different things.[/QUOTE]
I guess I know nothing about what I've been doing for the last 5 years.
I'm not saying that at all. Sure, you've been making these parts for 5 years. Have you been engineering them? I have been designing parts for 10+ years. The relationship between the two parts is what I'm referring to when I speak of heat cycling (and I use the term loosely). I'm not saying "heat treating".
Also, YOU posted the link to that article. Do you not agree with what it says?
I think maybe each of us has a different idea of what the other is talking about. And I think we're bordering on hijacking this thread.
I didn't do anything special after having FRPP 4.10s installed in my car, and there's been no whine, no vibration, no problems with them in over two years.