[geeteeohguy]

I'm rebuilding a '67 TH400 that I last used in 1993....it's been in storage since I yanked it out of my '67 GTO back then and replaced it with a donor trans at that time. Prior to removal, it always worked fine, but it always had a faint whine in first gear only. Back then, an AAMCO guy told me it was worn planetaries. Well, I tore it down today to inspect it and the planets appear ok. The only thing that looks questionable is the reverse drum..lt has slight grooves in it, that I can feel with my fingernail. Like a worn crank journal. The rear band is fine, as are all the frictions and steels. The seals are failing, but again, all the hard parts except the drum look like new. I can not find ANY information on how to inspect a TH400 drum to determine if it's servicable. Does anybody know if these drums need to be totally smooth, or is some scoring ok? Also, I wonder what would cause a first gear only whine. I measured the endplay front and rear during the teardown, and the input shaft endplay was out of spec at .040", but the rear was fine. I sure don't want to get it back in the car and have it whine all over again!! Any help greatly appreciated! Thanks.

[SD421]

Sounds like it needs a new filter or its the pump

http://www.oldspower.com/vb/showthread.php?t=1382

http://forums.aaca.org/f115/transmis...-a-192969.html

[stevep]

Some of those rear planetaries do not have a totally smooth band surface. If the band id not torn up, you should be fine.

Usually, a gear whine in 1st gear is the planets, even if you can't actually see any damage. Do the pinions feel smooth when you spin them? Can you tip the pinions from side to side? There should just be slight up and down play. If they do tip, you need to replace it.

Another thing that can cause a gear whine is metal to metal contact. So make sure that your mount wasn't collapsed.

[geeteeohguy]

Thanks, Steve. The band is fine with no issues. I will check the planets. Don, it's not the filter or pump. That would cause whine all the time. This is a whisper of a noise only in low gear. Not a pump issue. Thanks........

[geeteeohguy]

Got the trans all back together and found the source of the whine. The rear bushing had not been pressed in all the way during a previous build, and two Torrington bearings were wasted due to lack of rear end play. The endplay at teardown checked ok because the bearings were bad. On reassembly, I installed the bushing all the way in and used a different selective thrust washer (after installing new torrington bearings!) Both front and rear endplay's are now in spec, and with any luck, the trans will work as intended.