radiateu2

Ok here is what I have done so far to find the problem. This car is the one in my sig. I cant seem to find the source of vibration today I disconnected the tc and I still have the vibration so that tells me it is the engine and not the transmission I think although I pushed the tc back into the transmission as far as I could somehow the engine still rotated the tc a little. The balancer mark seems to be in the same spot ie. it doesnt appear that it slipped. I need your help with this one. Sure hope I dont have to tear the engine down again. I did notice the water pumpwas leaking fluid out of the weap hole so that will be replaced tomorrow. Does anyone have any suggestions or clues as to where to look and what to check now.

Thanks in advance,
Ed

radiateu2

ok here is an update. Yesterday after posting this I went back out to look some more. I noticed the passenger side engine mount doesnt look like the drivers side. It looks twisted in the cradle and not sitting right in other words the part that mounts on the engine is not seated on the rubber portion properly. Could this be a source of vibration at 2,000-2,500 rpm. Or should I be looking at a problem with the rotating assembly.

radiateu2

eventhough none of you replied or offered any suggestions I thought I might share with you what I found. When I built the engine I had to get a flexplate for a 2 piece seal crank, so I ordered one and received it, installed it, and up until now I thought I had the proper flex plate, I dont think I had any way of knowing which flex-plate to buy since I did not know what year and vehicle the engine I have came from. The flex-plate I purchased did not have a weight on it. I took the car to a local tranny shop to see if my torque converter was going bad. The guy at the tranny shop (who I trust very much in his expertise) felt the vibration and knew right away what it was. I purchased the flex plate with a weight from him and installed it in about an hour and low and behold no more vibrations.

I know many of you have the same problem without any thoughts or idea what could be wrong. So this is something for you to think about or look into.

Ed

Oh you dont have to drop the tranny completely either to replace it. Renove the three bolts holding the tc to flexplate Use threaded rod or long starter bolts in the lower 2 bell housing bolts holes remove the torque arm and drive shaft remove the rest of the short bell housing bolts and then slide the tranny back on the long bolts while supported by the floor jack. Unbolt the flex plate and install the new flex plate and tranny in reverse order.

jasonbennett

i have the same vibration in my truck but it is a 72 block. i didn't notice if i had a one piece or 2 piece seal flexplate, spinning the torque converter to line up differently seems to help but then it comes back. thanks for this thread i will have to check my flexplate now to see if i have the right one or if it's cracked. sorry i didn't see this earlier, but i don't think i would have been much help.

radiateu2

hey Jason its all good I didnt mean to seem like I was flaming there, I just wanted to share what I have learned. I had a one piece rear main seal block that was in the car when I bought it. The block was cracked so I bought a used engine from a machine shop that was a 2piece main seal. When I purchased the flex plate I was not aware that some vehicles used a flexplate with a weight and some didnt. Most came with the weight. The problem for me was not knowing what the motor came out of. If I knew that I would have been able to look up the flex-plate for that application with the right tooth count. Anyway....I wanted to share this with all since it seems to be an issue with a few people on here.

SLP IROC-Z

iTrader: (1)

its a pretty common problem, my car does it too. 305s are known to vibrate a little caus of their bore-stroke configuration :-( its somethin ive learned to deal with.

abcx09t

How do you tell which seal is in the engine? I have the SD 350 VTPI and I don't know what seal was installed.

Scott