ok so a few weeks ago i felt a vibration in what i thought was the tranny or rear end. well i had figured out to me i felt it from the tranny. well i took it to the transmission shop that i whole heartily trust and neither me or my family have had any problems with and have always been great. well they told me it was not in the drive line (tranny, U-joints, driveshaft, or rear end). so i took that and drove since then with it. but the whole time the vibration was still there after rotating and balancing my tires and new pads and rotors. well i was noticing it was very strong just as the tranny was in between shifts and at the end right before it shifted. but it wasnt to bad even the times i had it on the interstate running her sometimes out to 90+ with no problems.

Well the interstate portion all changed tonight. Me and Ann were going into Murfreesboro (bout 10 miles Via Interstate 24) and i was cruising along at 70 until i needed to pass someone so i wound the ole 351 up to around 80 and as it went between 73ish and 80 ish there was a VERY VERY bad vibration when i was in the throttle. but when i would let out the vibration would completely go away.

This to me seems almost like its not the actual transmission but Torque Converter. no im not real sure on how the TC functions but i know it locks/unlocks but im not sure when and why and at what speeds etc.
can someone diagnose this for me?



and huge thanks to any help at all.

 

a few people on another forum are saying it may be the harmonic balancer. does this sound right?

 

That's where I was going to place my bet. Deal w/ it soon.

 

does it vibrate when you rev it up in park or neutral? if not it wont be the balancer or the converter.

 

ill check in the morning.

 

well went out and drove it. put it up throught the gears manually. vibration is still there. reved it up in park. vibration is still there just not as noticable. i guess thats probably cause it aint vibrating through the tranny. not sure though. and its in all gears now. its getting worse and worse dramatically as the past 2 days have went buy. it seems like its worse between 20-35 mph. 50-60 mph and 75+ mph. not sure on rpms as i have no tach. and it only happens when im in the throttle. as soon as i let out the vibration goes away.

im thinking its the harmonic balancer.

 

If it is the harmonic balancer, it's going to get worse & so will the engine problems that will occur. If that's it, the effect will be worse under load &/or accelerating. Cruising, less so.

 

yep. its worse accelerating than cruising. and im gonna try to change it tomorrow.