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« on: April 12, 2024, 12:08:36 AM »
This has me a bit perplexed... I just changed the 8" diff in my 68 cougar from a 3.00 to a brand new, built by a local professional, 3.55. Nothing else changed, but now there's a driveline vibration that wasn't there before. It seems most noticeable at higher speeds, above 75 and under deceleration. Looking for any insights other than what's been bouncing around my brain...
Nothing else has been changed
Driveshaft has balancing washers on it
I flipped the driveshaft 180 just to make sure
No u joint caps came off
The diff is nice and quiet, I don't believe there's anything wrong with it
I did notice that the Driveshaft might be a bit long. It's appears to be an aftermarket custom one, but when unbolting it from the diff yoke, it doesn't slide forward enough to even clear the yoke all the way. But it did not have this vibration with the 3.00 diff...
Im thinking u joint or the driveshaft being too long...?