Digging this back up because I got curious about recommended break-in procedures this morning...
According to Eaton the TrueTrac carriers themselves require no break-in at all. Here's the direct quote from their "TrueTrac FAQ" page:
"While Truetrac units do not require a break-in for operation, the gears do “lap” together. While the time required to fully lap the gears will vary depending on driving style and loads, the units will operate smoother with age."
Source:
https://www.eaton.com/us/en-us/prod...rket-differentials/detroit-truetrac-faqs.html
Richmond Gear's ring and pinion install manual calls for a few short heat cycles like
@Supercharged111 mentioned. Here's what they say:
"A new ring and pinion installation, especially a high numeric ratio with new bearings, can cause an excessive heat buildup in the rear end and cause softening of the gear teeth and bearings if a break in is not performed.
Street vehicles should be driven at normal street driving speed for approximately 10 miles, then stop and let cool for 30 minutes. Do this 2 to 3 times. Towing vehicles need approximately 200 to 300 miles of normal street driving before being used for towing.
On circle track race cars make approximately 6 to 8 laps at slow speed, then let cool for 30 minutes. Make 6 to 8 more laps at slow speed, then 2 to 3 laps at full speed, then let cool again for 30 minutes.
Drag cars need only an initial run-in since they are driven short distances and heat is not normally a problem with proper lube and backlash allowance.
NOTE: If after the above break in is performed, overheating of the rear end is suspected, repeat the final portion of the break in procedures."
Here's a link to that manual, these instructions are on page 81:
https://www.richmondgear.com/wp-content/uploads/pdfs/richmond/Richmond_Catalog_Section2.pdf
One interesting observation is that I see no mention of changing the oil after break-in in either document. I'll probably still do it just for the peace of mind, but now I'm curious if it's really necessary in my situation.