Tons of things going on, a lot of it is little details. Need a small bracket here or a tweak of something there and before you know it many hours have disappeared.
One big thing:
The Getrag diff was not operating like an limited slip unit. At first we chalked it up to the fluid and additive still needing to get cycled around better since it hadn’t driven around much, but after a lot of figure 8’s in the parking lot and still no improvement I started digging. GM superseded part numbers so when you call your GM contact to find out if the PN on your diff is for an LSD, they might know that number was superseded by a different number or they miiiiight tell you that’s not a number that comes up in their system and have no idea. Eventually we got it nailed down and it turns out the salvage yard that advertised this diff as an LSD unit got it wrong. That was over a year ago so nothing to do now but buy another one.
As for those part numbers…
3.42 NOT LSD:
15793753 – superseded now by 25873499
3.42 LSD:
15793754 – superseded now by 25873500
New diff arrived, correct original PN on it. That diff now lives in the car.
