1997 chevy "through seat" vibration

I’m aware of the time line. The issue is still prevalent with recent models thus the comment.

There have been 3 or 4 new chassis since the 1997 truck. That means there is likely different solutions for each platform revision.

I do not have this issue on my 04. If I did, I’d start by balancing my driveshaft.

There is a warning label on the driveshaft of my GMC truck. Paraphrased; it basically says that removal or replacement of the driveshaft requires rebalancing before installation.

My 98 GMC truck does not vibrate either in the wheel or seats so I guess this weekend’s to-do job will be to create a vibration of some sort. Maybe loosen the carrier bolts… :wink:

Something I discovered a few years ago while replacing a pair of U-joints on my daughter’s 2005 Mustang. She had purchased the joints at O’Reillys in advance of my coming down there. Those joints have a design flaw which allows about .015 of an inch sideplay and which of course causes a vibration. Those joints came back out for a return and were replaced with Spicers which do not have that small amount of sideplay. Car was smooth as silk afterwards.

Might be something to keep in mind with store brand joints no matter which parts house provides them as odds are the joints could be from the same manufacturer but with different packaging.


Sometimes a driveshaft will be removed for servicing, and not be put back on w/the same orientation. Usually connects at the transmission yoke (if 4WD xfer case) and the differential yoke, and both of those connections can connected in more than one orientation. If driveshaft has a slip-joint (b/c two piece driveshaft) that could get put back together in a different orientation too I think. If u-joints got replaced, those can get put back together in a different orientations too. Lots of ways for a driveshaft to work fine, then get removed and be completely out of balance upon re-install. Fortunately there are driveshaft specialist shops in the more populated areas that know how to fix this problem.

Note to diy’ers: Before removing driveshaft use a crayon or similar to mark the orientation of all the joining-up places. You’ll have a much better chance of not having this problem upon re-install of the driveshaft.