OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Walk Behind Lawn Mower Frames Victa Lawn Mower Frames Assembly sequence for cutting disk bolt/washers

I have an ancient (about 1978) Victa with Briggs & Stratton 3.5 hp engine. I don't like tipping the oil out as a way to change the oil because I end up with oil in the muffler and it takes a while to get things settled down again. My new trick is to put the mower up on blocks, remove the cutting disk by unscrewing the central bolt, and taking out the oil drain plug by using a home-make tool consisting of two half inch drive sockets welded back to back. However when I did that, the next time I mowed the lawn the cutting disk came loose. Not sure if I put the bits back on in the wrong sequence, or just didn't torque up the central bolt sufficiently. Can someone tell me the assembly sequence please? I put the disk on first, so it will centralise on the spigot, then the special washer with the X-shaped cut out to engage with the matching X on the end of the crankshaft, then the flat washer to flatten out the X-washer. The X-washer is a Belleville type: it is dished and made from spring steel. I put it on hollow-side up. Was I right or wrong?

grumpy,

When putting the washer back on have the inside high side towards the bolt so that when you tighten up the bolt, it works like a spring washer.

I will try and do a drawing of what I am talking about and post it later today.

Thanks Bruce, that sounds like the same thing I meant when I said hollow side up. That way the outside diameter of the washer bears on the underside of the cutting disk, which should maximize the washer's capacity to transmit driving torque to the disk.

I'll look at the pic when you post it, to make sure I've understood you correctly.

grumpy,

As promised drawing is below.

Thanks Bruce,
I just tore my rather ancient Victa apart for another look, and it has a different design from the one in your sketch. There is a boss pressed or shrunk onto the crankshaft, but no boss on the blade plate which is a fairly elaborate pressing but flat in the center. The X-recess washer goes on after the blade plate, then a special, heavy washer goes after the X-recess washer. The special washer has a boss on one side and a recess on the other. On the boss side it has "BOLTHEAD SIDE" in raised-up lettering. By torquing up the bolt, the X-recess washer gets squeezed between the recess side of the special washer and the blade plate. I guess this makes sure the X-recess washer gets squeezed completely flat, by allowing the end of the crankshaft to enter the washer recess if necessary. By the way, if someone has invented a better way to hold the crankshaft from rotating (I just use a long piece of 2mm steel plate about 40mm wide) I'd be interested in seeing a picture or sketch.

Here is a tool used for holding the blade plate.

Thanks Bruce, but so far I can't figure out how to use it.(?)

Can anyone tell me the correct torque for the center bolt that holds the blade plate onto the crankshaft? I'm using 35 lb-ft (47 Newton-metres) but I'd hate to have it come apart again - it chews up the parts, including the end of the crankshaft when that happens. On the other hand I don't much want to strip the thread either.

I would more lean to 40-45 lb/ft

My usual "torque setting" is to get it pretty tight then lean fairly heavily on it.

Ok the problem is not with how tight you can do up the centre bolt but with the blade plate itself.

If the blade plate is shiny where the washer or blade plate boss sits then you will have to replace the blade plate.

Thanks Bruce, it's way beyond shiny, its heavily striated - circumferencial grooves in both sides of the blade plate, and the center hole in the blade plate has become so enlarged I've had to use a small centering bush. The blade plate is some kind of turbo type - complicated pressing with a major flange around the outside, and recesses for the blades to swing back into. It creates an awesome draft, and really packs the grass into the (unfortunately rather small) catcher. It didn't come loose mowing foot-tall wet kikuyu at 35 lb ft bolt torque a few days ago, and I'm hoping it will now rust a bit and settle in. If it moves again, I will have to take more serious action. Are those turbo blade plates available?