Auto flexplates

can a automactic flexplate 283 chevy lose a blance weight and viberate, do all flex plates have weight ? thanks

 

I guess it's possible for a spot weld to break and the wieght sling off but I have never seen it. Not all flex plates have weights but engines like the 400SBC are externally balanced with weights on the flex plate and the harmonic balancer is cut away on the inside. Make sure to use the correct parts when putting a new engine together.

 

this one is for a 400 external balance,it has a wieght at the top of it.

this is an internal balance

no weights

 

They can and do crack more often than you would think though. Also check your bellhousing bolts to make sure that they are tight and check the torque converter bolts to make sure that they are tight.

Pull the cover and shine a light up in there and look for cracks between the holes and around the bolt circle.

If you need to change it and want to do it yourself one thing that makes it easier is to get two long 3/8 bolts (ten inches or so) and put them in the bottom bell housing bolt holes and slide the trans back on them on a floor jack so that you have enough room between the flex plate and converter to get your ratchet and or torque wrench. Slide it back make the change, slide it forward and put the other four bolts back in and swap the bottom bolts back in. It saves a lot of fighting with the trans laying on your back. It's best to support the back of the engine though. On some I have put a short piece of board between the pan and crossmember or a chain across the frame rails under the pan with a block or two between the pan and the chain. Keeps the back of the engine from wanting to droop down so far.