Husqvarna transmissions?..

Is Husqvarna the only dirtbikes manufacturer to use the same transmissions on the different CC engines??

Mid 70's ('77) to early 80's ('81) 250, 360, 390, 420. Early case air cooled.

Early '80's ('81) to mid '80's ('84) 250, 430, 500. Newer case air cooled. The 250 has smaller crank diameter over the 430/500 case. But the 250 case can be made to fit the larger 430/500 crank.

I'm just surprised how many different cc engines were put n the same tranny. There bullet proof as long as there kept full of oil. If ran with a low oil level with prolonged use the gears can crystallize and the teeth crack. I do question the quality of the other gears in the tranny when I see some gears have cracked teeth.

Yamaha used the same transmission in the DT and RT enduros in the early 70's . I believe the 90/100, 125, and 175 models shared cases and transmissions between themselves. That is one of the reasons they were good deals to get started with

You will find the Euro manufacturers were the most frugal and got the most variety of what they produced. If you looked at Bultaco, Montesa, and Ossa in the 70's you would see exactly what you were talking about.

All the British manufacturers did the same, in fact they make the Euro manufacturers look profligate!

KTM used the same cases/transmission/cylinder castings for all their engines 72-79, they did the same thing as Husky and just machined the castings differently depending on what displacement it would be. Many years of Yamaha YZs and ITs shared major engine parts as did RMs/PEs and KX/KDXs. Today you can take the WR transmission gears out of the Yamaha WR250F and put them in the two stroke YZ250, which is basically what Yamaha did with their new YZ250X off road bike.

I put a ts125 motor into a rm125s frame years ago and mixed and matched bits from the internals.