Need help with vibration..........

[conoverbandit]

Hey Y'all,

In Feb. this year I bought a "tough one" engine from advance for our 93 Chevy G-20 van. I also bought new flexplate,plugs,wires,cap,button.I wound upo messing the dizzy up shortly after (long story) and bought a new one of these also.Slew of new sensors all the while trying to keep "trouble" at bay.......Ever since I put the motor in, I've had a "bad vibration" to try and figure out. It does it at idle really bad, the mirrors shake,the sunvisors jar, and anything inside thats loose just vibrates like heck.You can just bearly put pressure on the gas pedal and it will go away, somedays it runs great, some days it will vibrate your eye theeth out. Since doing this swap, I have had to re-build my tranny (4l60e) 3 times.The first time the guy said the converter swelled?(never heard of this) the second he told us the overdrive drum bearings and planateries went south, and now it's done it again.My first thought was shoddy workman ship, but I've thought about it for a while and we had'nt had any trouble out of the tranny till we did the swap. We towed like 2 k-5's one of them took us 624 miles round trip no problems all the while towing with a very tired 4.3 and a 4l60e in a full size swb van. When we did the swap that's when things starter to go south.I changed nothing on the crate motor I bought, just added the flex plate and my accessories, intake/TBI. Anyone got any ideas? (Besides selling it and getting a k-5 for the wife?) Anything I can try/do, one fella suggested I take the inspection cover off and take converter bolts loose and push it back, crank engine to try and isolate it that way.To see if it was the engine or tranny. He (and my dad) seem to think the tranny's just to worn out to hold a rebuild.....(close to 200,000 total, but only about 20,000 since it was gone through the very first time.) Any help appreciated,

Thanks,



Wayne

 

[diesel4me]

I heard this...

I read about torque converter "balloning" in a towing magazine,on 454's with TH400's..seen it once in person at a tranny shop too..most every converter that does that,according to the article and the rebuilder who showed me that one, said the cause is usually a restricted or plugged cooler line,or cooler,and the back pressure builds up in the converter and causes it to swell up!

Other guys have other theories,like too much torque for the converter to handle....this only happens mostly to trucks towing heavy loads or used as plow trucks for the most part..it also said the motors thrust bearings are usually shot after this happend,and had lots of end play in the crank,due to the converter balloning outward,and trying to push the crank out of the front of the block.. ..hope that isn't your vibration. ..

 

[projectcop]

Wayne;
You say you replaced the flex plate? Are you 100% sure that they gave you the correct one? Some motors are balanced differently, and if you have a flex plate with the wrong or non balance weights when you need different one or no weights at all could create that problem.
example: 350 and 400 small block are balanced differntly. 350 flex plate on 400 would create vibration at idle.
Check it out.
George

 

[David E]

Guys
I'm new to the forum but have had a 82 1500 pickup w/ 6.2 diesel for years (300,000 miles). When I replace the fuel injection pump I picked up a heavy vibration at idle just like the one described. Goes away with the litest touch on the throttle. Does not do it with the trans in park, just with it in gear. Any suggestions? Could be something to do with the fi pump?
David E