Hi there,

I have recently had a recon gearbox and torque converter fitted at great expense. Everything seemed to be fine until 2,500 miles later a loud knocking noise was heard. Initially I thought it was the engine, but soon realized it was the gearbox.

The car was returned to the garage that fitted the gearbox, and when it was stripped down, the flex plate was found to be damaged. Damaged is an understatement! The plate had completely broken around the 8 fixing bolts that attach the flex plate to the crankshaft.

A new flex plate has been fitted and I was charged accordingly as the garage claimed it was a coincidence. As there is no damage around the torque converter mounting holes, I accepted this... However. Now I have read that flex plates generally fracture because either the torque converter isn't tightened onto the flex plate correctly, or the crankshaft and gearbox shaft are not aligned correctly. The latter can be due to the dowels between the engine and gearbox are missing. I was wondering if the dowels can be checked easily now that everything has been put back together?
Does anyone know if the dowels are the hollow type, with bolts through them, or the solid type?

The garage are well established and very helpful. I just don't want the same thing to happen in another 2,500 miles because the root cause of the problem wasn't found.

Any suggestions would be greatly appreciated.
Thank you.

 

My immediate answer to this breakage, is Bolts not tightened properly or as you say dowels not fitted. I recon that by looking at damaged Flexy you could ascertain what went wrong, as in longitudinal or damaged holes. But of course Garage would dispute this.

 

make sure you get the broken flex plate off of them and get to an engineer for an assessment and then small claims court

Regards
Richard

 

I have the old flex plate.

There is no damage around any of the bolt holes. So nothing was obviously banging around. But if one of the torque converter bolts was not tightened correctly, I imagine this could stress the flex plate.

The flex plate is completely broken outside of the 8 crankshaft mounting bolts, and several cracks outwards from the center, towards the outer perimeter.

Does anyone know if the dowels can be seen when the gearbox is attached to the engine?

Thanks for the replies so far.