360/904 Torque Converter Mystery

[kdkdracing]

360/904 running correct vibration dampner, B&M flexplate, TCI neutral balanced converter.
Changed to Boss Hog neutral balanced converter with more stall. Now the car shakes violently
at through out the RPM range. any ideas???

 

[NC Engine Builder]

No vibration before converter swap? Sounds like converter

 

[kdkdracing]

No vibration before converter swap? Sounds like converter

No, put the old part back in. Runs smooth. Not as much fun.

 

[kdkdracing]

No vibration before converter swap? Sounds like converter

Not sure if you received this the first time. Sketchy internet up in the mountains.
No, Put the old part back in. Runs smooth. Not as much fun.

 

[cosgig]

Sounds like the new converter is offset balanced, and the flexplate is also. Maybe Boss Hog made it offset balanced because you mentioned it going into a 360?

Just throwing ideas out there!

 

[kdkdracing]

Sounds like the new converter is offset balanced, and the flexplate is also. Maybe Boss Hog made it offset balanced because you mentioned it going into a 360?

Just throwing ideas out there!

Thanks, any idea is good. I can't return the part for a refund because they say it is good. sooo I'm out $496.00

 

[cosgig]

Thanks, any idea is good. I can't return the part for a refund because they say it is good. sooo I'm out $496.00

Not that it’s a fun job, but maybe you could try a neutral balanced flexplate with the Boss hog?

 

[d55dave]

Is there large weight(S) on the boss converter? Is the hub that seats in the crank register the right diameter?

 

[Plymouth 65]

Proper register diameter, early 904's used the small snout diameter converter? 65'

 

[cosgig]

Proper register diameter, early 904's used the small snout diameter converter? 65'

The input spline count is also different between the 67 and earlier and the 68 and later, I doubt the incorrect spline would even go on!

 

[oldkimmer]

Thanks, any idea is good. I can't return the part for a refund because they say it is good. sooo I'm out $496.00

That’s a total crock. Shove it up their azz and never deal with them again. Kim

 

[kdkdracing]

Is there large weight(S) on the boss converter? Is the hub that seats in the crank register the right diameter?

No weights. Both converters are neutral balanced. Confirmed by both manufactures. Measured the crank before installation and both converters. .005 clearance

 

[cosgig]

No weights. Both converters are neutral balanced. Confirmed by both manufactures. Measured the crank before installation and both converters. .005 clearance

Must be something in the Boss Hog converter I would guess. Very strange that one would have no vibration, and the other so much with the same flexplate