Noob at posting

[ijess1]

Hey Folks! This is my first time posting so please bear with me! I'm generally good at doing my own work but have hit a brick wall here. I bought a 87 J10 with the engine sitting in the bed! Fun! Dropped the oil pan and found molley grease on the journals and there was cute little cardboard caps in the spark plug holes! Never seen that one. It was missing the torque converter. Got a new one from a friend and very reputable. I found the flexplate in the bed and ass/u/me/d it went to this engine. It did bolt up. I didn't notice at the time if it was weighted and now I am having vibration problems! I have less than 700 miles on it and the rear main seal is leaking like a siv! Replaced the harmonic balancer with new and it helped for just a while. Any advice on how to determine if this is the wrong flex plate without pulling trans or engine?

[rang-a-stang]

Welcome to the forum! We're glad you're here! Did you post some pics yet?

What engine do you have? How long did the engine sit?

I would start with a compression check, first to make sure all cylinders are good. Also, are you sure all cylinders are firing?

If its a V8, the rear main seal is pretty easy to replace and they're cheap. I got nothing on your flexplate though.

[ijess1]

Hey Rang, It is a 360. I don't know how long it sat. I haven't done a compression test because it runs so good. It only starts to drop out about 200-2500 rpms. That is also when the vibration becomes more prominent. I have been dragging my feet on pulling the inspection plate and having someone rev the engine to see if the flex plate wobbles. Thanks for the response!

[rang-a-stang]

Any updates?