The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - Holding my 3-speed in 3rd gear or pops out

D'Monsta · 11-12-2021, 08:52 AM

I am dealing with a similar situation now.. Started with popping out of third gear last year but recently I get hellacious vibration between 50 and 70 MPH.. When I back off the throttle (decrease load on trans) the vibration lessens but when I hit the accelerator again, the vibration happens.. I'm thinking front bearing, carrier bearing, bad synchros.. Time for a rebuild. I do have an SM-319 with overdrive here, condition unknown, but I can clean it up and try it without the OD connected and see what happens.. Gotta get Old Jim ready for the holiday season..

11-12-2021, 08:52 AM	#10
D'Monsta Registered User Join Date: Aug 2020 Location: Charlotte Posts: 48	Re: Holding my 3-speed in 3rd gear or pops out I am dealing with a similar situation now.. Started with popping out of third gear last year but recently I get hellacious vibration between 50 and 70 MPH.. When I back off the throttle (decrease load on trans) the vibration lessens but when I hit the accelerator again, the vibration happens.. I'm thinking front bearing, carrier bearing, bad synchros.. Time for a rebuild. I do have an SM-319 with overdrive here, condition unknown, but I can clean it up and try it without the OD connected and see what happens.. Gotta get Old Jim ready for the holiday season..