OutdoorKing Repair Forum Forums Repairs and Maintenance Questions On Ride On Mowers Questions On Victa Ride On Mower Frames Victa Pro 12 - Friction Rings

With the friction ring plates on an 1989 victa pro 12. Does anyone know whether they are cork or break pad material. I have had a look at mine which appear to be original, and they are very thin and look like break pad material. If they are how thick is the material supposed to be and what is the external and internal diameters. From what i have found out so far is they are the same as a rover rancher. Also does anyone know where i can purchase a pair of bonnet straps for the 1989 Victa pro 12, Part no RD17669A. All help is appreciated.

Leshby, I'm not familiar with the transmission on your mower, but I'm guessing it is the variable ratio type that uses two disks at right angles to each other, so the edge of one disk runs against the flat side of the other disk. Drive ratio is varied by moving the edge-on disk across the flat-side disk, to change the effective radius it is running at. The transmission control lever usually has several detent positions to fix the radius and therefore the drive ratio. When you look at the flat disk, it usually has grooves worn in it in the running positions corresponding to the detent positions set by the transmission control lever. When those transmissions only have three speeds, it may be possible to alter the adjustment of the transmission control linkage to obtain three different speeds that do not correspond to the worn patches on the flat disk.

Those transmissions require rather high contact pressures between the edge-on wheel and the surface of the flat wheel, and cannot use a soft friction material like cork. The material will be something quite similar to the brake lining material used for drum brakes. (Disk brake friction material is much thicker, and is normally pre-cut and bonded in the factory: only drum brake shoes are re-lined when they wear out.)

The short answer is that relining your transmission disk will require clutch facing or brake lining material such as is used for relining drum brakes or manufacturing clutch plates. Because of the very high local pressures on the lining caused by the tiny contact area between the two disks, I suggest it will need to be properly bonded onto the disk using the hot bonding process used for brake linings. Note that even when that bonding process is used by brake shops, sometimes failures occur and the linings fall off, causing considerable annoyance, if not loss of life, to the motorist. It is best to have the relining job done by someone who has done it before. This is quite different to the bonding process required to put clutch facings onto ride-on mower clutch plates - those can successfully be attached with contact cement, but the same does not apply to two-disk transmissions.

Mine only has the two large discs under the seat with the heel and toe forward and reverse.

That sounds more like a Greenfield system: two disk clutches, going in opposite directions, one each for forward and reverse. If they are flat disks that squeeze together flat side to flat side, like an automotive clutch, it is quite different. There has been discussion on this site before about relining flat plate clutches for Greenfield ride-ons. The usual method so far has been to get the rings of brake lining material from wherever you can (probably a brake shop, but you could decide to remove the linings from an unwanted automotive clutch plate of suitable diameter), and glue them to the flat clutch plate with contact cement. You can even see posted pictures of how a member went about that job, if you search Greenfield threads here on Outdoorking. It was only a few months ago.

I spoke to the local mower shop and they say that they replace them with cork ones the same as the rover rancher. will that work of go for the brake pad material.

It depends on how much torque has to be transmitted, and how much the clutch has to slip. If you manoeuvre around to get between things when you are cutting, especially if you are on a slope, the clutch tends to take a beating. Cork clutches are not good for that kind of service, they tend to be "in or out" clutches. Also, the amount of torque you can transmit through a clutch depends on how much clamping pressure you have - and cork can't stand high clamping pressures. Generally cork is for very light duty clutches that are not used for controlled starts. I don't think it is suitable for this job.