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R51/3: How can I take the gearbox out?

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schrader7032
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R51/3: How can I take the gearbox out?

Post by schrader7032 »

Micha -

It may be possible to do similar to how I remove the tranny on my R69S before I removed the engine. I was headed to a complete overhaul but thought that taking the tranny out first would make it easier to handle the engine. I would presume that this could be one on your bike.

I had already removed the exhaust pipes, clutch connections, and air filter...battery too. I then removed the fasteners that connect the output flange on the transmission to the driveshaft. I also loosened the front engine mount and took out the rear engine mount. I had a small hydraulic jack under the rear of the engine for support.

Then, I slowly jacked the rear of the engine up until I had enough clearance to unfasten the tranny and slide it up and back. Here's a series of pictures where Marco documents a clutch change on an R69S in about 30 minutes.

http://www.snafu.org/saturday/2005/jim.html

Another way would be to remove the pins that hold the swingarm to the chassis. Then you disconnect the 4 bolts holding the output flange of the tranny to the driveshaft and pull the entire rear suspension backwards...maybe hold it in place with a bungee or rope. That should give you enough clearance to unbolt the tranny and move it rearward.

Kurt in S.A.
Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2
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Allan.Atherton
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Re: R51/3: How can I take the gearbox out?

Post by Allan.Atherton »

Is it possible to pull it out without the engine? How can it be done? What is best to uncouple first? Thanks, Micha.
Here's where it was done in a shelter at a rally site - the "tech session" to replace a flywheel. The method for removing the transmission was to remove the rear swing arm:
http://aatherton05.home.insightbb.com/H ... all03.html

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Darryl.Richman
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R51/3: How can I take the gearbox out?

Post by Darryl.Richman »

You can remove the trans from a /3 bike, in a similar fashion to how the above descriptions show for a /2. As there is no swingarm on a /3, the beginning is a bit different:
  1. Remove the rear tire.
  2. Remove the top cap on the right side plunger.
  3. Remove the rear brake rod from the short arm on the final drive.
  4. If you have a clearance problem, remove the small plate in the front right side of the rear fender.
  5. Push the rubber dust cover forward and loosen the LEFT HAND thread bell cover from the front of the final drive.
  6. Push on the U-joint that was hidden under the bell cover, inwards. This should turn the final drive and also the driveshaft, pulling the driveshaft back and separating it from the rear of the transmission.
    [/list:o]
    Now you can follow the other directions to remove the transmission.
--Darryl Richman

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VBMWMO
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R51/3: How can I take the gearbox out?

Post by VBMWMO »

Is it possible to pull it out without the engine? How can it be done? What is best to uncouple first? Thanks, Micha.
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