1986 K10 3spd manual tranny issue

[Rascal407]

Hi new poster here,

         My 1986 Chevy K10 305 4x4, 3spd manual w/ L recently developed a very noticeable shudder/jerking when I shift into 3rd? The engine idles and revs fine. Runs smooth in 1st and 2nd but the whole truck jerks/jumps when shifted into 3rd? If I rev high in 2nd and accelerate to 40-45mph then shift into 3rd, it is not as noticable but still present. Any ideas on what this could be?


             Thanks 
                       Bob

[zieg85]

Sounds like a plug and or plug wire starting to go under load.  My $.02

[Rascal407]

I hope its that simple...

[DirtyLittleSecret]

Ah, sounds familiar!
I had a rather similiar circumstance, but it was in 2nd gear rather than 3rd.  Oh, and mostly under load.  Noticed it immediately after I replaced the body mounts (what there was left of them).  It was the rear driveline falling apart, but didnt "feel" like a drive vibration.  $175 and I got a new drive with all new u-joints all around.  Now it rides like butta.
Just another thing to check...

[DirtyLittleSecret]

Could also be that your clutch got contaminated.

[DnStClr]

Did you check the motor mounts? It sounds like a bad one.

[Rascal407]

Thanks for all the help. I believe its the wires. I was under the hood checking to make sure the wires werent contacting anything too hot and jiggled all the connections to the cap and plugs. Test drove it around the neighborhood and it ran fine. Drove it to work and it developed the same problem on the way back.

[Rascal407]

If I don't sell the truck this weekend, which I am not completely sure if I want to or not, I'll be replacing the plugs and wires shortly.

[Rascal407]

...and the winner is......



zieg85

the air tube/pump on the passenger side corroded away, leaving one rusted nut in the manifold, about 2 months ago,I got the bolt out after alot of wd40 soaking and eventual torching and drilling, replaced the air pump/tube. the plug wires were attached to the old tube, i never reattached them to the new tube. One of the wires was resting too close to the manifold.