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Author:  Rodney [ Sat Oct 01, 2016 1:35 am ]
Post subject:  Gearboxes

Does anyone know if you can use a 750 paso gearbox in a 500 pantah case or what other gearboxes that may
be used .



Author:  angelix [ Mon Oct 03, 2016 8:57 am ]
Post subject:  Re: Gearboxes

The "modern" Pantahs are extremely similar and often lots of parts are interchangeable.

my experiece relates to the 750 Elefant engine with dry clutck (same as the Paso), I fitted half gearbox from the original engine and half from a monster 620

Basically the gearbox is made of three major parts, the primary, the secondary and the selector drum

the primary can be interchanged between engines of the same type, the main difference resides in the number of teeth of the FIRST gear which is integral part of the shaft; some primary shafts are slightly longer on one side but this can be fixed using a lathe.

the drums seems to be all the same

The secondary shaft is the interesting one... the later versions are longer and allow the chain sprocket to allign better in case you fit a wider rear wheel; in my case by fitting a different secondary shaft i manafe to get the extra inch i needed to allign the chain and accomodate a 180 tyre.

The gear ratios COULD be different depending on the models, buy all gears are interchangeable (except the first gear on the primary) so eventually you can make a mix and match

The best would be to remove your gearbox and compare it with other models.
Here you can see some pictures of my gearbox on th left thesre is the original from a Elefant 750 dry clutch, on the right the one from a M600/620

cambio.JPG [ 53.84 KiB | Viewed 3175 times ]

Author:  Rodney [ Mon Oct 03, 2016 9:34 am ]
Post subject:  Re: Gearboxes

Thanks for the photos , putting the engine together from scratch , so don't have a box at the present , what did you do about the different clutch and the smaller size if the primary side.

Author:  angelix [ Fri Oct 07, 2016 10:18 am ]
Post subject:  Re: Gearboxes

on my engine I used the primary shaft from the old bike and the secondary of the M600/620 simply to avoid issues on the clutch as i wanted to keep it "dry" Paso style.

in my case I am not sure if I made a mistake... the shaft I had was from an Elefant 750 which has a "short" first gear; most probably it would have been better to source a Paso Primary gear shaft which had a longer ratio. At the time I could not find a good one so I decided to go with what I had.

I did choose different gears for the 2-3-4-5, now they are closer to each other like in a racing gearbox; on paper it works but on the road I have not tried yet.

The new M900 SS900 907 916 stile clutches work the opposite way compared to the old Paso so the pushrod basically goes through the primary shaft ; this needs specific crankcases so the this option is not feasable on the old engines.

The M/SS 400, 600 620 & 750 from 90 onwards have the same clutch system as the Paso but is wet and the Nut holding the primary and basket is bigger.

I suppose some adaptation can be done, but I cannot give any advice as I have never done that.

The primary shaft of the old pasos is very similar to the new ones the only difference in in the diameter of the nut and the lenght of the shaht were the bearing is fitted.

The pictures I posted are a little bit deceiving as both shafts have the bearing still stuck on them so on the right side (picture) they might look different, when in fact they are the same diameter and the only difference on that side is that the more modern is a little bit longer (can be shortened with a lathe)

My suggestion is to buy them (they can be very chap on ebay) and make some tests, once you finished just post thme back on ebay ;)

Author:  paso750 [ Wed Oct 26, 2016 5:22 pm ]
Post subject:  Re: Gearboxes

this is a different topic. I wonder if putting a 6 speed gearbox in a P750/Sport engine case is possible.
http://www.ducati.ms/forums/57-superspo ... -case.html

Author:  jayh [ Wed Dec 21, 2016 11:23 am ]
Post subject:  Re: Gearboxes

Yes Rodney it is possible to fit the paso transmission into the earlier pantah cases,as I have done it to mine.Some considerations are dry clutch is probably required,bearings slightly smaller on paso so need bushing,slight grinding of crank case interior to fit new gear race ,different output shaft splines so different sprockets,paso selector fitted no problems,slight grinding of crancase for primary drive gear (compare to later model crank cases which have a slight mound here).All of my grinding done with rotary burr by hand,all bearing bushes machined down from original bearing outers.I had to wing it as I could find no definite instructions and unfortubately I didnt document it .

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