Sm 465 question
 

Hey everyone, I have a 76 gmc with a sm 465 trans and it shifts pretty rough. When I down shift into 2nd it usually grinds. It's kinda hard to find the gears when normally driving.

If I replace the shifter with it make the shifting smoother? Is it possible to replace the shifter and what does everyone like? The trans is a top load trans and the truck has a removable trans tunnel.

Re: Sm 465 question
 

The SM465 is a top loaded, top shifting truck style transmission. The shifter, for lack of a better term is a "stick" that drops into the top of the trans. You can replace the stick if the bottom is worn and no longer is doing it's job. Hard to find gears can be worn internal shifting parts. The grinding can be clutch out of adjustment, or worn synchro teeth (dog ears). Try double clutching and slide it into gear.

Re: Sm 465 question
 

Agree.

Said differently the shifter is basically a giant screwdriver stuck in the top of the trans. Replacing it probably will not make any difference.

K

Re: Sm 465 question
 

x2 on Keith's shifter info. I just had the clutch replaced and the input shaft re-sleeved on my SM465. I had hard shifting and it is better now. Unless this problem just came up, you know that grannys are not smooth shifters. The mechanics working on my truck said they rarely rebuild SM465s - usually the internals are in good shape. Aside from the worn input shaft, the one on my 83 was OK. With a bad clutch, you should hear some rattling and chattering when you shift.

Re: Sm 465 question
 

On thing that I've noticed is the clutch pedal seems be walking up. The pedal starts to hum in 3rd and 4th gear. The first time I heard it I thought it was the dash vibrating. If I give it a tap it goes back down and stops vibrating.

Re: Sm 465 question
 

See the 3 holes in the shifter tower in the pic? I seem to recall the shifter is held in by a roll pin through there. There's an article somewhere about fixing a wallowed out hole in the shifter. It may help with finding but not grinding.
https://www.google.com/search?q=+sm4...ter&gws_rd=ssl