I recently had my c4 overhauled on my 73 Maverick 302 c4 and I noticed a vibration in the vehicle when revving the engine in park and also when driving at 50-55 on the highway. It didn't have this vibration prior to her tranny rebuild. I'm wondering if the torque converter is slightly out of whack or wasn't filled properly. They also rebuilt the converter. Waiting on a call back from the mechanic at the transmission shop for advice. The reason I'm thinking converter is that I can also feel the vibration when sitting in park and revving the motor. apx 2000-2500 rpm.
Sounds like you are on the right track with thinking it is the converter, finding a vibration can really be pia
I talked to the mechanic and he's going to give it a good once over. He said he knows everything that would cause the vibration and how to find it. He said more times than not, it's not the converter. The transmission mount is new and looks good.
One thing to note...When installing the new 302, I was going to replace the motor mounts with new ones. However, the new ones had a fitment issue and the main bolt to connect it to the frame or crossmember would not go all the way through the mount. So I reinstalled the old mounts. They were in good shape except the rubber was hard as hell. But at least they fit.
are you using the same flexplate and if so is it in good shape? is there a drain plug in the converter if so is it coming out the hole in the flexplate? "They also rebuilt the converter."... never heard of a transmission shop doing this.
I'm of the belief your convertor is the issue. Not sure why your shop would rebuild a convertor if it doesn't have issues? My transmission shop corrected a driveline vibration by rebuilding my torque convertor. I've since replaced my convertor a few times with convertors with different stall speeds. The centering of the drive hub on the impeller is critical. I found some off-the-shelf units with the centering of the drive hub out of spec. Guaranteed vibration.
I contacted the mechanic and he told me he did not rebuild the converter. It was in good condition. When I get the maverick back next week after installing the highway gears in the rear end, I'm taking it back to the transmission shop and have him to find the cause of the vibration.
