I think I found the vibe
I got 2001 DTS with the same vibe....I think I found it....
Been having a problem with the front axle. 6 months ago tried to replace....but could not get the hub out of trans.
Yesterday, had new axle and axle shaft puller here. Got the axle snub out of trans. Snub has very strange wear. (see pic)
I think in this car the trans shaft bushing is gone. The bad news is this bushing is not available.....you have to buy the complete case extension..... plus select washers etc....mess...
So the new axle is in. It was a slightly different part. Noticably heavier on the transmission side.
Now the vibe is worse with the heavier part....ahhhh.....clue.
Got this theroy from another post on net....similar GM FWD vibe issue...
"The bearing/bushing/case in the trans axle, where the axle enters, was worn and the axle was loose.
At high speeds the axle would bow out at the inner CV joint (run in an elliptical fashion).
This whipping effect caused the vibration."
I think this is exactly whats going on. Please note the damaged bearing surface on the snub. (see picture)
I can pry on the axle snub and it moves.
My car is going in for hail damage this week. So the trans will get fixed next week.
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