Thickness of Ducati Mille clutch large seal
Posted: Fri Sep 04, 2026 6:23 am
The Mille uses 65x85x10mm seals.
https://www.ducaticlassics.com/shop/937 ... l-65x85x10
The modern Ducatis uses 75x95x12mm.
https://www.corsasbk.com/product/930403 ... 03c44deab6
Since I'm starting making drawings for a straightcut gearset for the Mille, with modern Ducati clutchparts, I wonder if it's better to increase the thickness of the seal.
I'm still looking for a front gear for measuring if someone has one for sale or if someone can lend me one.
I enclose the drawing for the large gear, Nova in Uk can start making the gears at the end of this year.
This means that I'll have to weld some material to the inner clutchcover.
Is the thickness of the seal the problem that causes failure of the seal on the Mille
I wonder if there is room for 2mm extra material behind the clutchcenter?
Or is it better to add 1mm at the back and 1mm at the front?
I enclose a picture of the Gilardoni cover I've got.
I've taken it out to 90mm, but I will take it out to 95mm for a better/larger seal.
Ai says this.........
"No, the standard OEM rotary shaft oil seal for Ducati dry clutch housing covers is 75x95x12 mm (part number 93040341A / 93040341C), not 75x95x10 mm. [1] (https://www.kfm-motorraeder.de/en/item/ducati-93040341C), [2] (https://www.gothamcycles.com/ducati-eng ... -seal.html)Dimensions: The correct thickness/width for the clutch-side cover oil seal is 12 mm, meaning a 10 mm wide seal will be too thin for proper seating depth in standard Ducati dry clutch applications. [1] (https://www.gothamcycles.com/ducati-eng ... -seal.html)Material: Viton (FKM) rotary shaft seals (typically brown/reddish-brown) are widely available in 75x95x10 from industrial bearing suppliers, but using a 10 mm variant instead of the specified 12 mm OEM thickness risks improper axial retention unless a specific aftermarket housing spacer or alternative design is accommodated."
Thankful for comments.
https://www.ducaticlassics.com/shop/937 ... l-65x85x10
The modern Ducatis uses 75x95x12mm.
https://www.corsasbk.com/product/930403 ... 03c44deab6
Since I'm starting making drawings for a straightcut gearset for the Mille, with modern Ducati clutchparts, I wonder if it's better to increase the thickness of the seal.
I'm still looking for a front gear for measuring if someone has one for sale or if someone can lend me one.
I enclose the drawing for the large gear, Nova in Uk can start making the gears at the end of this year.
This means that I'll have to weld some material to the inner clutchcover.
Is the thickness of the seal the problem that causes failure of the seal on the Mille
I wonder if there is room for 2mm extra material behind the clutchcenter?
Or is it better to add 1mm at the back and 1mm at the front?
I enclose a picture of the Gilardoni cover I've got.
I've taken it out to 90mm, but I will take it out to 95mm for a better/larger seal.
Ai says this.........
"No, the standard OEM rotary shaft oil seal for Ducati dry clutch housing covers is 75x95x12 mm (part number 93040341A / 93040341C), not 75x95x10 mm. [1] (https://www.kfm-motorraeder.de/en/item/ducati-93040341C), [2] (https://www.gothamcycles.com/ducati-eng ... -seal.html)Dimensions: The correct thickness/width for the clutch-side cover oil seal is 12 mm, meaning a 10 mm wide seal will be too thin for proper seating depth in standard Ducati dry clutch applications. [1] (https://www.gothamcycles.com/ducati-eng ... -seal.html)Material: Viton (FKM) rotary shaft seals (typically brown/reddish-brown) are widely available in 75x95x10 from industrial bearing suppliers, but using a 10 mm variant instead of the specified 12 mm OEM thickness risks improper axial retention unless a specific aftermarket housing spacer or alternative design is accommodated."
Thankful for comments.