vibration at 1500RPM in P or N converter weights??

[crash340]

So, what is the likelyhood of the vibration being in the trans rather than the engine? the vibration increases with RPM so its something rotating

[ShelbyDogg]

Possible, but not likely.  The drum and pump spin but are usually very balanced from the factory. The off-balance for a cast 340 is very little. My flywheels are drilled with a single hole, about 1/2" deep to make a neutral balanced flywheel work. Are you sure that you have the right converter? Maybe someone here with a 340 cast crank converter can take a pic of the weights to compare yours to?

[734406pk]

I might have a 340 cast converter. If I can find it, I'll post a picture.

[crash340]

I have a later 360 converter here and it has masive weights on it, according to the Carl Munroe TF Trans handbook, the weights I have are correct for the 73, 340 converter, two small weights,  .880" long, .620 wide and .177 thick.

Guys, I really appreciate your input on this very much, thanks.

I'm just not ready to build the 408 yet, but I may have to bring that forward. I Have a 77 360 donor engine I just pulled the heads from and worst case it will clean up with a .020 over bore

[crash340]

So, for a quick check, lets say i take the converter inspection cover off, rotate the converter so as the drain plug is at BDC (6 O'clock) , balance weights either side of teh drain plug. then take a look at the harmonic balancer, where should the counter wieght be on the converter, 6 O'clock as well??? this will be an easy check, just need to confirm location basically, with a timing light, all the timing marks show correct so I'm guessing the balancer is in ok condition, not slipped etc.

[roadman5312]

look at your post count, make another quick

[crash340]

Damn,,, ok so now im out of that maybe my vibration will go as well???

[roadman5312]

Damn,,, ok so now im out of that maybe my vibration will go as well???

                   If the vib is gone now let me know where to mail the bill to.    

[crash340]

Will south pacific pesos be ok? exchange rate is not good ATM

[crash340]

So, for a quick check, lets say i take the converter inspection cover off, rotate the converter so as the drain plug is at BDC (6 O'clock) , balance weights either side of teh drain plug. then take a look at the harmonic balancer, where should the counter wieght be on the converter, 6 O'clock as well??? this will be an easy check, just need to confirm location basically, with a timing light, all the timing marks show correct so I'm guessing the balancer is in ok condition, not slipped etc.

[Chryco Psycho]

the weight should be 180* off from front to back

[sassygreen]

I thought for sure I had a driveline problem as well. Turned out to be a leaking intake. Gasket blew out in between two intake runners. Spray wd 40 on intake and head gasket mating surface and see if idle increases. If it does then you have a leaking intake gasket. Worth a try before you gut your car.

[crash340]

Thanks CP
SG, did you engine run smooth, start easy etc before you noticed the vibration? Mine is like a clock

[734406pk]

can't find an340 cast crank converter. I suggest exhausting all possibilities and then remove the oil pan and check the casting number on the crank to verify that it is actually a cast crank. it sure sounds like you have some sort of parts mismatch.??

[crash340]

I've just had to replace the alternator, ran it up with my hand on the alternator and the vibration is felt badly though the alternator, put my hand on the timing cover and no where near the same vibration, I have to take it on a run tonight but tomorrow I'll drop the belt off the alternator start it and see what happens. The old alt I took off had ****ty bearing, loose in the front housing