Linhof Kardan Bi maintenance question

[Jim Andrada]

I have an 8 x 10 Kardan Bi. The locking knobs on the rear center tilt don't really lock the back tightly - they make it a bit harder to tilt, but by no means lock it in place. The detents hold OK as long as I don't push it around too much when inserting a film holder but I have to be careful or it slips.

Does anyone know if this is adjustable in any way? (Bob S.???)

Thanks

[Bob Salomon]

Ask Marflex@aol.com