OK, another post, assuming I get the head gasket job under control. I replaced the u-joints and center bearing & support a couple of years back. Did this before on a 240 very successfully. Ever since then she passes thru a vibe between like 42 and 48 mph, real annoying. I marked the shaft, etc with paint and know that it's aligned. Had a shop put it on the rack, and we carefully checked all marks and looked at u-joints/support, etc. All seemed well.

I'm thinking a rebuilt/refurbed shaft may be the way to go to get this under control, maybe something is just a bit out with this one or the new u-joints suck perhaps. Anyone ever take this route with success? As always, thanks for the great help.

Mike

i have done this job a few times and there are two practical solutions.

one i s near free but takes a bit of time to get it balanced just right.

buy some lead wheel balance weights the kind that are sticky tape for use on allow rims. find the location of the driveshaft where there are factory install extra weights for balance purpose. normally just in front of the rear axle.
see how the weight is distributed. one side should have a bit more weight than the other. now place a 1/4 oz weight on the low side and hold it there with a large stainless band clamp. take it for a drive. if itsa better but not perfect add more wieight until the vibration goes away.
if its worse remove weight and add to the high side and try again.

the other method of solving your problem which costs a bit of money but not much and is much faster is to buy a drive shaft assembly whole from a junk yard. they will usually sell them fairly cheap as there is no call for them.

Fiddled with shimming though it's complete guess work and a pain since it's up and down off the stands. I'm thinking new (or different) driveshaft at this point in time. Thanks for the tips.

93 should have the bearing type output shaft, not the bushing type that wears on the earlier cars.
A driveshaft shop can balance what you have though, which may eliminate any errors there.
My 93 had an issue, mostly at takeoff. There was a TSB about driveline vibes. I went so far as to change driveshafts, with no difference. Shimming the center bearing Up 11mm toward the tunnel was what finally did it.

Have you checked for play in the trans output shaft? See if you can shake the front u-joint yoke up and down.

Yep, did that, it's rock solid, the 93's don't have the worn bushing issue, but either way it's good. Thanks.