Help with Graziano

Hi there. Im Ben
My father, Peter and I had a GT40 built for us. The end product was not what were hoping for and we have been trouble shooting ever since we have had the car.
We have a Graziano transmission. It is noisy and clunks when turning at low speeds. Looking for help if anyone on here has or is using a Graziano, what oil are you using and how to change the oil in these boxes
Cheers
Ben

Welcome to GT40S Ben. What kind of GT40 did you purchase ?? There are some builders in Australia and hopefully they will chime in. I think most of the guys here in the states have RCR SLC’s, GTR’s, and I know of one T70mk3b that are using Grazianos. Be interested in what car you have. Pictures are always welcome.
Thank You

Regards Brian