SM465 L-2-3-4, can't shift into 2nd unless completely stopped (solved)

[mtnmankev]

Here's my suggestion until the space aliens quit messing with you, when moving slowly (2 to 5 mph perhaps) shift into neutral, let clutch out, and "blip" the gas pedal a little to spin the gears, stab the clutch pedal in and see if it goes into gear.
The theory is just like driving a semi, shift by rpm so the gears line up and mesh.
That has almost always worked for me every vehicle I have owned that didn't shift into gear as the theory of having synchros should have taken care of.
With a little careful practice, you should have no trouble using the same method to shift into granny gear (not synchronized) while moving, it's just a matter of getting the rpm right with the vehicle speed.

 

[idahovette]

Exactly my thoughts @mtnmankev

 

[discuspro]

Mtnmankev, gold sticker for you! That works! I've heard about this quite a bit, but I kept getting it wrong. I would have the clutch in, then rev, then try the shift into 2nd (L-2-3-4). Doesn't work.

Doing what you said to rev, hit the clutch, and shift works!

 

[mtnmankev]

Mtnmankev, gold sticker for you! That works! I've heard about this quite a bit, but I kept getting it wrong. I would have the clutch in, then rev, then try the shift into 2nd (L-2-3-4). Doesn't work.

Doing what you said to rev, hit the clutch, and shift works!

Thanks for the gold sticker ... I'm glad it worked for you !!
As you have learned, the secret is to get ALL the gears spinning.
I have driven stick shifts since 1968, and semis over the road long haul, so I have encountered just about anything possible with a clutch and manual transmission in my life.
I'm thankful I can share my experience to help others while I am still able to.
This forum is chock full of many GREAT people with LOTS of know-how and experience, and they are always willing to help a fellow member, all I ask is when you are able to help somebody, pass the favor along and have them do the same thing.
Together, we are strong and can enjoy our trucks.

 

[Redfish]

FWIW, mine doesn't like to be downshifted to first at any speed much faster than I can walk. I have learned to just leave it in 2nd and rely on the low end torque when making low speed turns. My truck has just 58K miles but someone else drove it the first 56K so I cannot say what it was like when new.

The truck I drove through my high school years was a '77 GMC 4wd and I am pretty sure I remember it being the same way.

 

[mtnmankev]

I have found many manuals that don't like to be downshifted, for whatever reason it may be.
Probably mainly due to wear from high miles.
Synchros are soft brass and they do tend to wear quickly.