Date:         Thu, 4 Mar 1999 16:05:49 -0500
Reply-To:     Martin Jagersand <jag@CS.YALE.EDU>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Martin Jagersand <jag@CS.YALE.EDU>
Subject:      Re: Trans main shaft pulled out!
In-Reply-To:  <199903041734.MAA03841@netra.cs.yale.edu> (message from Automatic
              digest processor on Thu, 4 Mar 1999 09:34:52 -0800)

Gary,

I'd strongly recommend alternative 2 below. Do it right since you're
rebuilding the engine anyway.

It should only take an hour or two to pop the bellhousing and get
the stud out. Main problem is that hands (at least mine) don't fit
inside the gearbox with the diff installed. Use long neddle noose pliers
to get the stud out.

Also while at it: replace the input shaft seal (likely damaged when
the shaft was pulled through), and pilot bearing (likely cause of
the shaft sticking to the engine and pulling out in the first
place.) Each one is just a few $ (5 or 6) from the flaps.

A small explanation for those who have never opened a gearbox:
The input shaft is threaded on with a small (like M5 I think) stud,
but it is not the stud that transfers the engine torque. It would
break immediately! Instead the reverse gear slides ove the two
shafts and connects them firmly along the axis of the shaft, but
allowing some flex in other directions. This is because the other
end of the input shaft sticks into the engine drive plate (where
the pilot bearing is). If the shaft was "stiff" in the gearbox
it would be under load all the time since the engine -bellhousing -
tranny are different castings and not perfectly aligned. The
loose coupling through the splined reverse gear acts like a flex
coupling.

The gear is held down by a circlip (sometimes a pain to get off)
on the input shaft. If the input shaft is stuck in either the pilot
bearing or clutch (check the splines) it is easy to break the
stud when pulling the trans and engine apart.

/Martin
--
Westy 1.9l Turbo Diesel
Quantum 1.6l Turbo Diesel

Martin Jagersand                 email: jag@cs.yale.edu
Computer Science Department             jag@cs.rochester.edu
Yale University

        Slow down and visit the VW diesel Westy page:
          WWW: http://www.cs.rochester.edu/u/jag/vw
-------------------------------------------------------------------


> From:    Tom Carrington <tcarrington@RELITECH.COM>
>
> Gary:
>
> What happened is the threaded stud that holds the input shaft snapped.
> Did the snap ring come out with the shaft? If not, it may be in the
> bottom of the trans. It happens from time to time. You have a few
> options:
>
> 1. Stick the shaft back in there, make sure it engages the splines
> properly. When you re-install the engine, the engine will prevent the
> shaft from coming out. The only risk is that the missing snap ring could
> float around and wedge between the pinion or differential gears. Iv'e
> done this before when I had no money and this happened.
>
> 2. Replace the broken stud. You need to undo the 8 bolts holding on the
> bell-housing and pull it off. Replace the broken stud and snap ring.
> Find and remove the broken ring. Re-assemble with a new gasket and fill
> the tranny with fresh gear oil. Some of the details on how to do this
> can be seen on my website at:
> http://www.relitech.com/tomc/vanagon2.htm

> Good luck!