360 engine vibrates, Torque converter has no weights

[bowsix101]

i have a 1978 dodge Winnebago with a 360.
the Vin says its should have a 440 but somewhere along the way it was switched for a 360. it has a horrible vibration in it and i have looked at the torque converter and it does not have any weights on it and it has the stock flex plate with no weights. which would be best get a weight kit and weld on, new weighted flex plate or new weighted torque converter. the transmission was behind the 440 so guessing i need one of the parts listed since its externally balanced and the front balance is fine.

thanks for any replies.

[Wantawinnie]

The 440 transmission does not bolt up to any small block engines. If it is still the original tranny are you sure it is a 360? To answer your question I would buy a weighted flexplate but that involves pulling the transmission.

[bowsix101]

yea on the drivers side block it says 360. gotta pull it out anyway to replace rear main seal.
thanks for the reply.

[Slantsixness]

It sounds like you have two possible problems:

1. The Torque converter is not a 26 balanced converter (there is a balanced flexplate that is is available, but it's not a 100% fix, but allows you to use a 318 torque converter on a 360.

2. Harmonic balancer may be from a 318. especially if there is no observable counterwieght on it. If it's only an inch thick, its a 318 harmonic balancer. the 360 is super hard to find for the M-350 Motorhome chassis, the Car ones don't work unless you use the entire cooling and pully system from a Car engine.

3. Lastly, the vibration may or may not be the engine at all. a Bad front U-joint will give you a similar vibration. (notice no vibration at 3500RPM in Neutral, then it's the ujoint or driveline somewhere, even driveshaft angle and center bearing will produce odd vibrations)