To rebuild or not to rebuild (SM 465)

[captnk10]

I bought a 79' GMC K1500 with a rebuilt engine and transfer case. It looks like the original SM465 transmission has never been touched. It does have a new clutch and drives good except for a whirring noise in 3rd gear that goes away when clutch is disengaged. It has 160,000 mi. Should I get it rebuilt? I want to put a gearvendors overdrive in it and make it a daily driver.
Thanks for your input.

 

[squaredeal91]

SM465 is my favorite transmission personally. Definitely worth rebuilding in my thoughts. Gear vendors are cool too!

 

[captnk10]

Adding the Gear Vendors now would make a rebuild later more difficult.

 

[Shorty81]

SM465 is my favorite transmission personally. Definitely worth rebuilding in my thoughts. Gear vendors are cool too!

I second this motion. SM465 rocks!

 

[PrairieDrifter]

I've got three of em. Im picking up 3 more for $50 lol. They're like $200 some dollars for a simple rebuild. You can do it yourself too.

Check out GebBuilt on YouTube.

 

[akchevrolet]

I've got three of em. Im picking up 3 more for $50 lol. They're like $200 some dollars for a simple rebuild. You can do it yourself too.

Check out GebBuilt on YouTube.

Shoot send one my way for a 4x4. haha. love to put one in my k5. if i had one id prolly rebuild it.

 

[Strick]

Dad's old crew has over 400K miles on the original SM465. It too has the third gear howl but it's not deafening or sounds mechanically disastrous. Years back I swapped in another SM465 from a C60 dump; this tranny howled in neutral. I suppose this was from running the PTO for the hydro unit. Anyways, I swapped his original back in...and still have not rebuilt it.

HS

 

[Craig Nedrow]

I have had to rebuild mine a few times, but for an International Loadstar. Pretty simple, nice that the stick comes off so easy so you can drop it out. I have one hooked to a 205 setting out on the back 40...I like the newer transmissions better. That design replaced the 421? which came in the 47-54 for sure, not sure when the switch. Old tech. The gear venders is awesome, but look at the price!!!! Well over three thousand https://www.gearvendors.com/product/manual-4-speed-muncie-m-465-np-205/. It can be done, but it will cost yah.