I just got my new-to-me Sammy together (rebuilt engine, new clutch, paint, and exhaust) and it has a drive line whine in 4th and 5th.

It is on pull or coast, and is worst between 35-55mph, after which the noise of the tires is as loud as the whine (either the tire noise is louder, or the whine gets quieter).

Normally, I'd suspect the rear differential, but the guys here who say they are familiar w/ Sammies say it's a common transmission problem, and not the rear dif. It'd louder if you stick your head outside of either side window (don't remember that w/ dif noise).

If it's there at all in 1-2-3 gears, I can't hear it, even at the speed it starts being noticeable in 4th.

All of the other posts mentioning transmission whine address the LOWER gears, not 4th and 5th.

If it IS the transmission, do I need new gears, or is the whine most likely bearings? On pull, it sound kinda' like poorly adjusted differential gears, but on coast, when you let off the throttle, it sounds more like bearing noise (more growly, less high pitched "whiney").

It was there before the rebuild, BTW. It was just hard to hear over the headache-producing exhaust system (no cat, and a cherry-bomb terminating halfway under the vehicle). Now with a "legal" exhaust (cat, muffler, and tailpipe past the rear bumper for state inspection), the engine and exhaust is so quiet the whine is very obvious.

Thanks-
Bob

Sounds like trans bearings, especially since you hear it in 4th and 5th, same
shaft and bearing set, pull and change the bearings before it goes all south
and gets expensive

Wild

OK.

If it's bearings on that shaft, I see kits out there w/ bearings, or bearings and synchros.

Might as well go both since the 3rd gear synchro sometimes "snicks" as it slides into gear.

I've never done a transmission internally, so is this one easy to do w/o special tools, or any tools beyond simple hand tools and gear pullers (I have a full set of these, at least)? I no longer have a lift at my disposal, so I'd be doing it on jack stands in a normal garage on the floor.

When I removed the engine for rebuild, I removed the full nose clip and pulled the eng/trans together, but if I do the trans, I'd probably try to just drop the transmission alone.

Is rhe easiest way to remove the trans-to-transfer driveshaft, then go straight back w/ the transmission, then tip the nose down and out to the front?

The crossmember is welded in place, so that seemed the most logical.

thanks,
Bob 

Sounds like trans bearings, especially since you hear it in 4th and 5th, same
shaft and bearing set, pull and change the bearings before it goes all south
and gets expensive

Wild

Agree.