Triumph Repair: TR7 4 speed input shaft removal, shaft removal, input shaft

Question
QUESTION: Howard,

  I'm rebuilding the 4 speed in my 76 TR7, (pops out of 3rd on decel) I was wondering the best way to pull the input shaft out.  Factory manual refers to a special tool - looks like a cylinder that goes over the shaft and screws to it's side and a slide hammer pulls it all out with the bearing.  Haynes manual talks about using a drift to tap the bearing out, but there isn't much room to maneuver behind the bearing with the gears in the way.  Any suggestions ?

   Thanks,

   Steve.

ANSWER: Hi Steve,
Yes the Haynes manual is correct and just use a 1/4 inch or 5/16 inch mild steel rod the keep driving as far to either side as possible and at times as it comes out bump the end of the input shaft with a wooden block to straighten it up as you go. Most of the British gearboxes are done that way on the rear bearing also when the factory tool is not available.

Howard

---------- FOLLOW-UP ----------


Input shaft bearing   QUESTION: Howard,

  Thanks for the reply, so I'm driving on the outside race of the bearing on the inside of the gearbox as in the photo ?  All the while trying not to chip any teeth on the input gear ?  I guess a rod about a foot long is best ?  Also, I noticed a notch in the gearbox above the bearing - perhaps designed for a puller ?

  Thanks,

  Steve.


ANSWER: Yes Steve, you have it aligned correctly except DON'T use that punch because it is hardened steel and will damage the bearing. Use a long piece of mild steel rod and hit the bearing race as far to each side as you can reach and even then you can't get far enough apart to be 180 degrees from each strike so you have to alternate using a block out on the end of the input shaft to keep knocking it straight since the only way it will come out is straight out.

I never seen any puller for it and I worked for two different Triumph dealerships back then.

Howard

---------- FOLLOW-UP ----------


Rear Gearbox Bearing   QUESTION: Howard,

  I got some 1/4 inch rod, cut it to about 10 inches and drove out the bearing & input shaft without too much trouble, - thanks for the great advice !

  Now I'm trying to get the other bearing out, where the main shaft exits the gearbox to the rear.  The manual says to remove the circlip holding the bearing to the shaft - I guess the one on the shaft in front of the bearing outside the gearbox, then pull out the bearing with 2 screwdrivers behind the circlip on the edges of the bearing.  I managed to get it about 1/4 inch out, then the first gear butts up against the inside of the gearbox and I can't make any more progress.  I suspect the inner race of the bearing is frozen on the shaft, and some part of the main shaft gear train is not letting the shaft move any more rearward.  I've attached a photo.  Am I correct and any suggestions ?

  Thanks,

  Steve.

Answer
Yes, that is a common problem also, so what you have to do is to put a piece of metal in between the large snap ring on the bearing and the back of the case. put one on each side and use a block of wood or such on the end of the output shaft and a hammer to drive the shaft back into the gearbox. On the ones that are tight you will have to keep putting thicker pieces of metal between the snap ring and the case and keep bumping the shaft back in towards the gearbox. Be careful to not get anything inside in a bind when you drive the shaft in.

You have to alternate between bumping the shaft in and knocking the bearing out of the case. Some tight ones are still tight on the shaft even after the bearing is clear of the case.

Howard