Healey BN4/6 bell housing vs BN7/BT7 differences.

[busybrit]

Just fitted the short block engine assembly and transmission into a BN7 to find out the engine that did turn over, is now jammed solid. After pulling the transmission I found the correct 10" clutch pressure plate was catching on the inside of the bell housing. Conclusion the transmission is from a BN4 or BN6 that should have a 9" clutch.

Has anyone had this issue and modified the inside of the bell housing to accommodate the larger clutch? It looks very possible as it is only just catching.

I thought of changing the bell housing for the correct BN7/BT7 but it has an oil seal fitted, and the hole for the shaft looks too large for the shaft in the BN4/6 box. Moss list the shaft as being a different part, so I suspect I'm right.

I thought about just changing the clutch assembly for the smaller 9" unit, but I think the flywheels are different. (What a mess. :mad-new: )

So back to my question, anyone ground the inside of the BN4/6 housing to suit the larger clutch?

 

[British_Recovery]

I put the bell housing from a 3000 (10" clutch) onto the 100-six gearbox with no difficulty. It would be a good time to check for the small pad, in the bell housing recess, that keeps the shifting fork rods from moving too far forward.
Bob

 

[busybrit]

I may do the swap to the 100/6 box and the 3000 bell housing as you did. But for now, I've ground out the material in the 100/6 housing just in front of the clutch fork, it wasn't very much.

Johnb