SM465 locking between gears

[Jordan Goodwin]

Haven’t driven the truck in 10 years, but working on putting her back on the road. When it was parked, we had an issue with the trans shifter occasionally getting locked between gears when shifting. It sometimes seemed to take forever fiddling with it to get it moving and into gear again. Any idea what usually causes this? I should mention the truck is an ‘85 K30, and my dear dad SWEARS there was a recall for this issue in that year. But many other things he has been convinced of on this truck have also not proven out… and as for me, I’m a total newbie just learning.

 

[Strick]

IF the floor unbolts from that truck it will make repairs much easier. You can gain access to remove the top plate with shift rail while still in the truck.
You can also start by pulling the shifter & inspecting both sides of the flange on it. I'd also pull the fill plug to check the fluid. You may want to drain it & fill with new oil as well.

HS

 

[Jordan Goodwin]

IF the floor unbolts from that truck it will make repairs much easier. You can gain access to remove the top plate with shift rail while still in the truck.
You can also start by pulling the shifter & inspecting both sides of the flange on it. I'd also pull the fill plug to check the fluid. You may want to drain it & fill with new oil as well.

HS

Thanks! I don’t think I can access the top plate through the floor, but I will definitely check, and I’ll check out that flange at a bare minimum. I already wanted to change the fluid, which was one reason I wanted to see what else I could look at before putting new fluid in.

 

[PrairieDrifter]

I would guess synchros are pretty well used up. The brass synchros are supposed to make the shifts smooth and seamless.

 

[vr1967]

Pull the shift lever and check for slop in the pins. (Circled below) slop in them will cause shifting problems.

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