Another Harmonic Balancer question?????????

[FlDart360]

Does this picture give enough detail to tell if this is an externally balanced harmonic balance? The motor is a 360LA which I know from reading previous post is externally balance. I don’t feel any weights any ware on the backside of it but I do see the machined recessed area on the front which I believe means its balanced? It measures an inch and a quarter wide.

 

[mderoy340]

external balance

 

[Derrick Kidwell]

Don't know about that but la 360 had weights on torque convertor or flywheels manual trans

 

[Valkman]

Looks like a later model 360 balancer.

 

[FlDart360]

Ok so the transmission is a 727 should the flexplate be balanced also and the torque converter neutral or balanced?

 

[FlDart360]

I did some interstate driving today for the first time since owning the car and noticed a vibration coming on at 3000 RPM. I can recreate it sitting in the driveway in park holding the engine at 3000 RPM. I figured I should start eliminating things.

 

[Valkman]

Ok so the transmission is a 727 should the flexplate be balanced also and the torque converter neutral or balanced?

Just the torque converter is balanced, the flexplate is not

 

[Derrick Kidwell]

Just the torque converter is balanced, the flexplate is not

Right on!

 

[MopaR&D]

I did some interstate driving today for the first time since owning the car and noticed a vibration coming on at 3000 RPM. I can recreate it sitting in the driveway in park holding the engine at 3000 RPM. I figured I should start eliminating things.

How bad of a vibration? Factory balancing on older Mopar engines is known to be pretty bad, still check the torque converter for weights and look if any might have come off (they're spot-welded IIRC).

 

[FlDart360]

How bad of a vibration? Factory balancing on older Mopar engines is known to be pretty bad, still check the torque converter for weights and look if any might have come off (they're spot-welded IIRC).

Is it possible to see by removing the small cover at the bottom of the bell housing or will I need to pull the tranny?

 

[nm9stheham]

If stock parts for the flexplate and TC, then as in post #7. If aftermarket, then the flexplate can have a weight or cutout, and then the TC would typically not have a weight. So look for either combination. Start by removing the inspection cover; you should see what you need to see

Balancing is a minimization procedure, not a complete elimination process for standard V8 engine balancing. And there are other sources of vibration like driveshafts, imbalanced or bent. Some factory cars (of many makes) came with weights attached to the back of the transmission tailshaft housing to help damp overall assembly vibrations. So diagnosing this can be difficult, but you have a good start by being able to re-create this in neutral, sitting still. It is very likely in the engine/trans area.

 

[MopaR&D]

Is it possible to see by removing the small cover at the bottom of the bell housing or will I need to pull the tranny?

You might be able to see from that but if you remove the entire inspection plate (held on by the starter and some small bolts) it should be pretty easy to see everything in there.