I've owned my 75 mav 2 dr 302 for almost 2 years and there has been this vibration that's driven me nuts the whole time. I've replaced rear springs, rear axle bearings, rebuilt the 3rd member, straightend and balanced the drive shaft,rebuilt the engine,rebuilt the c4 trans with a new torque converter, rear brake drums and new tires! Know the vibration is somewhat worse, so finally isolated the vibration to the engine {mounted bell housing to engine with trans removed}. My question is it possible that the new harmonic balancer is nfg, it is a NAPA # 600-5226 manufactored by Dorman.I ordered a new balancer from Summit Racing manufactored by pioneer, has anyone had any similar experiences?
i dont know about those balancers specificly. but the balance of the motor is important and there are several things that need to considered. has the motor been rebuilt? if it has, then there is a chance that it was not balanced during the rebuild. it could have been balanced but the flex plate or balancer could have been replaced with one that did not match the balance that was done to it. once i had somebody who found out that they had a crack in a cylinder that was causing a vibration in the motor. do you know the histor of this motor? is it the orignal motor or could it have been replaced with a newer motor? is your igniton system in good shape? plugs wires cap and rotor?
I had the motor rebuilt it is the orignal motor it was bored 60 over [310 cid],however it was not balanced, which to my understanding is s.o.p. for the intended use of this car [daily driver] the shop that rebuilt the trans said the flexplate was ok and was correct for the car and that their feeling was that the tranny was the orignal. Installed new mallory HEI dist. and new Ford Racing wires swaped out the mallory cap for a msd cap.
Is the vibration only at idle/park? Thats what mine did it vibrated alot when it was in idling, then went away when it reved up. i ended up putting in new motor mounts and 80% of the vibration went away...
whats s.o.p.? for the motor to have been bored over requires new pistons. if the pistons have a significant weight difference between each other or if they just have different weight than the previous pistons will cause a vibration. i belive that you need to get it balanced.
standard operating procedure{s.o.p.} Installed new harmonic balancer cured some of the vibration issue however their still is a vibration, pulling engine this week and going ahead with balancing.
