MV Tooth Extraction, at Weare Rally - Transmission Problems

[Phil Waterman]

Hi All

Well today got back to working in the shop, and the project was to press apart the lower cluster to replace the gear with broken tooth. I had some real concern about how difficult it was going to be to press off the 3 different gears and spacers on the lower cluster. There is nothing in any of my manuals about replacing these gears, yet it must have been common because I have found NOS individual replacement gears. The gears appeared to be a press fit on the cluster shaft with 4 pins running down the shaft in groves, with each of the gears having matching groves. My fear had been that these gears were shrunk onto the shaft.

To make the discription to follow here is the exploded parts view.


The first photo shows my simple bearing press unit nothing fancy I've used it for years and because it works never have gotten around to replacing it with a real bearing press. The big surprise was that the Counter Shaft Drive Gear (the first to be removed) came off with relatively little force. As each gear and spacer was removed I marked it with order of position. The rest of the gears came off as equally well with no extreme pressure from the little jack needed, in fact pressure was so light that it didn't even mark the wooden blocks.

What became obvious once I started to reassemble was that I should have marked all the gear as to which way they faced. As (all but one of) the gears have a beveled in the direction they engage, the other side being flat cut. Of course started off by putting on the wrong way around (2nd photo. Back to the house to print out a photo of the cluster I'd taken earlier on this photo I added ARROWS showing the correct direction for the gears (3rd photo).

Back to reassembly, the gears are not a hand fit but when heated 200F they are very nearly a drop on fit. (4th photo) Used old electric fry pan and IR Gun to heat all the gears to 200F then with a pair of thick gloves it was out of the frying pan and on to the shaft.

So replacing gears on the lower cluster turns out to be no big deal.

Cheers Phil