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Re: Welding clutch fork to cross shaft TR6 TR250

To: 6pack@autox.team.net, Triumphs@autox.team.net, emanteno@comcast.net
Subject: Re: Welding clutch fork to cross shaft TR6 TR250
From: Don Malling <dmallin@attglobal.net>
Date: Thu, 08 Sep 2005 09:27:13 -0400
Hmmmm.... Maybe adding a taper pin is not as hard as I thought. This is from 
Nelson's Buckeye stuff.
The reamer is only $9.50. I had expected this would be much more involved than 
it is. I'm not a 
machinist.

Don Malling

Added Taper Pin:  Another alternative is to use a taper pin instead of a bolt 
or expansion pin.  The 
standard taper is 1/4 inch per foot.   I made a sample using  a #5 taper pin.   
 In this case one 
drills a 1/4 inch hole and then uses a reamer ($9.50) to shape the taper in the 
hole as shown in 
left photo below.   Taper pins are sized by their large end diameter,  0.29 
inches in the case of 
the # 5 pin. A  2 inch pin that has a small end diameter of about 0.25 inches 
was selected.  The 
hole was reamed so that about 3/8 inches of the small end extended beyond the 
fork casting.  That 
3/8 inch length was threaded 1/4-28 TPI and the pin secured with a nyloc nut.  
The excess part of 
the larger end was cut off.  The finished pin is shown installed in the right 
photo below.     The 
taper pin has the obvious  advantage of a very good fit and is easy to 
fabricate.    This is 
probably my favorite choice at the moment.

Those who insist on a larger pin can select a # 6 pin that has a 0.34 inch big 
end diameter (and buy 
a #6 reamer).  The hole should be drilled 5/16 inch and reamed so that the part 
of the small end of 
the pin where it exits the fork casting is just a few thousands larger than 
5/16 inch.  The small 
end can then be threaded 5/16 - 24 TPI and equipped with a 5/16 nyloc nut.  In 
this case the big end 
of the pin will be nearly flush with the fork casting.







Sally or Dick Taylor wrote:
> Don---The clutch operating shaft has to come out the side of the case in
> order to remove the fork, T/O bearing and such. Welding the fork to the
> shaft will certainly take the load from the fork pin, if that is the
> goal. But so will adding a second pin, in the form of a bolt, or a roll
> pin  Doing it this way not only takes the load off the tapered fork pin
> (when this second "pin" is snug) but is removeable, for when the time
> comes. As you surmised, welding the fork to the shaft means cutting the
> shaft and removing it in two pieces, also when the time comes.
> 
> Dick
> 
> Don wrote:
> Subject: Welding clutch fork to cross shaft TR6 TR250 
> What are the list's thoughts about welding the clutch fork to the cross
> shaft. Will I have to cut the shaft to remove/replace the clutch release
> bearing if I weld it? Seems for the cost of a shaft and release fork
> it's an easy and sure way out of the broken pin problem -- pulling the
> transmission etc. 
> Don Malling 




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