72MonteMan

Sorry for my delayed response...I don't get on the site frequently. I appreciate all the input received. That's the great thing about this club. There's always someone who has the answer, or information to get you pointed in the right direction. Thanks everyone!

A number of years ago, I had obtained information on a gentleman who restored OEM Radio Assemblies. He had a website and unfortunately, when our computer died, my bookmark/favorite for his website died with the computer. I have no recollection of this gentleman's name, or his website. Does anyone have a recommendation for a quality business or individual who can restore and work on the OEM AM/FM/8-Track Stereo Radios installed in the First Generation Monte Carlos. Specifically, I'm interested in getting my 8-Track Player functioning again. It's been a long time since I've been on the Forum and appreciate your help. Here's to "Letting the Good Times Roll", as sung by "The Cars".

Is there a chance one of the universal joints could be causing the vibration?

Governor Oil Pressure and Modulator Oil Pressure are used to control your upshifts. Strictly Governor Pressure is used to control downshifts. For a forced 3-2 downshift, there is an electric solenoid activated by a switch located either on your accelerator pedal, or it could even be on the carburetor. Since this circuit is only used to control a downshift under heavy load, I don't know if this is a primary area of concern. If the weights on the governor are sticking, it could raise the line pressure and force it to shift earlier regardless of engine vacuum (modulator pressure). Is is possible that the 2-3 shift valve is sticking?

I agree with Wallaby- Check your fluid level first. I am not an expert on the GM transmissions, but generally the "D" selection uses a combination of sprags and clutch packs to engage the transmission. I believe that in "L1" the mechanical holding power is done with a brake (overrides the sprag) that requires fluid to be applied. If you do not have enough fluid flow to create the right amount of pressure, the brake will not function correctly. I had a Chevelle that did something similar, but it only did it when it was cold outside. Not sure of the temp's lately in MO, but this may also have an effect since the viscousity of the fluid is impacted by the colder temp's. Keep up posted!