Sm465 Rattle At Idle

I have a rebuilt sm465 behind my Dauntless 225. It rattles at idle like crazy. No noise at all with the clutch pushed in. I originally installed the new Advance Adapters mainshaft and bushings and put it back together with the old, but in great shape bearings. Rattled when I installed it. Ran it a bit and pulled it back out. I thought input bearing before I rebuilt it. Sounds the same after the rebuild which is now a few years and thousands of miles ago. The fluid is spotless, no flakes or anything even with a few years of pulling campers and trailers plus about 20,000 miles or more on it. Is it just the little paint shaker 6 rattling the internals? Maybe I am just too fussy. Are these transmissions notably rattly? When I rebuilt it, I did everything new, bearings, synchros, and updates, like the sleeve instead of snap rings. What am I missing?

 

If you run it in gear on jackstands, is the noise still there? If yes, in all gears? How about if you push on the brakes a little to apply some resistance?

 

I will have to get it up on jackstands again. It's been a few years since I tried figuring it out. The throw out has free play before engaging the clutch fingers, so I don't figure it to be that, but I will have to get the mirror out and confirm that later.

 

If you push the clutch in slowly, at what point does the noise disappear? If it’s soon (i.e., if the trans is still spinning) then it’s most likely the throw out bearing rattling around. If it’s when the pedal is deeper in its travel (as the transmission stops spinning), then it’s most likely something internal.

 

Doesn't the sm465 have some o-rings in the shift cane to absorb some harmonics?

 

The shifter is spring loaded, never seen an o-ring on one.

 

I’ve seen clutch release bearings make a horrible rattle when the spring clips on the release arm were broken or the fork was worn where it engaged the release arm. Simple check, adjust the clutch linkage just until the slack is taken up removing the clearance between the bearing and the pressure plate assembly fingers. If it goes away it is a release bearing/arm issue. If it doesn’t time to investigate the transmission further.

 

Applying a slight amount of pressure to the clutch pedal doesn't change the rattle at all. Push in the clutch so the trans stops spinning, the noise goes away. Put a little pressure against the shifter in 2nd 3rd and 4 the, the rattle goes away. Let the pressure off, rattle comes back, although not quite as loud. When gear oil is hot, much louder.

 

Does the 465 have the nylon tips on the shift forks? My T18 has some chatter but only in low/low down steep grade at low rpm ( I'm not convinced its not power lock clutch chatter) Everything is rebuilt but the shift tower, I have a kit for it. I think maybe things are drifting just enough inside due to slop.

 

I'm wondering if it's the shift fork tips myself. I thought everything was good looking but honestly I don't remember, so I may be pulling the top off to have a look.

 

My SM465 rattles and whines. I just rev the engine louder to drown it out. ;-

Seriously, this thing is effectively bullet proof so I don't worry about the LS power hurting it, but it is so slow to shift and noisy. If I had a CJ6 or 7 I would have gone with a more modern transmission but the 465 is the right length for an early CJ5, i.e. very short.

Mike