6 replies to this topic

[Jammy]

Talking about the two big buggers (ball bearings), one going in gearbox casing at the flywheel end, and the other in the gearbox webbing in the middle.

I managed to take the flywheel end one out last night with a big flat headed screwdriver, but it was hard to tap it out straight, and I did mark the edge of where the bearing race sits (the edge, not the face). Just wondering if there is a better method to be able to tap out all around the race with a little more ease and precision?

[mini_kel]

Guessworks will know! Or try a brass punch

[Jammy]

Yea, Haynes mentioned a brass punch, but I still can't understand how you'd use a brass punch to tap around the bottom of the bearing to keep it straight.

[JetBLICK]

used a wooden mallet or similar to knock the whole mainshaft towards the bearing through the first motion shaft hole. Be careful not to split the syncros. Doin this you can get the bearing on its way out. Then pull the mainshaft back and you'll have some resonable clearance to get a drift or your tool of choice behind the bearing to drift it out.

Bill soilis had a pretty clever 'tool' he used on his builder DVD - 3 'c' washers off the crank end (that hold the primary gear in place) taped together so you can push evenly on the centre of the bearing.

good luck

[Dan]

Best practise? Have the correct special tools.

Or:

Make a tool. For the third motion bearing, a very flat/parallel block of hardwood cut to a diameter slightly less (that bit is very important) than the third motion bearing size and the thickness of the gap between the side of first gear and the bearing, with a slot in the middle the same width as the shaft. The first motion bearing is even easier, the official tool is a slide hammer with an adaptor to pull on the first motion shaft thread. Get a new first motion shaft nut and weld it to an adaptor from a slide hammer set (these are pretty cheap at most tool shops), better still keep the new nut and weld your old one to the hammer.

With the first motion shaft and bearing out of the way, put the block in between the first gear and the third motion bearing to completely lock the first gear into place. Then just drift the whole mainshaft towards the end case and it will push the bearing out. Make sure the selector fork moves with the shaft until you can seperate them, if it stays still it will force the synchro off the hub as the shaft moves and you will loos the detants. If the block is flat faced it will damage the ball bearings and mean they need replacing, if you want a tool that will allow the bearing to be re-used you need to use a router and make a groove around the block to accept the balls and make it press only on the bearing races. The official tool is the same thing but made from steel, I'll see if I can get a picture of one.

[Jammy]

Hmm, don't worry if you can't find a picture. I've got a workshop manual at home which I think has pictures of all the special tools...

[icklemini]

1st motion bearing - i pull it out with the first motion gear.. i use a slide hammer and an adapter i spun up in the lathe that winds onto the end of the gear and into the slide hammer (as per the proper tool)..

for those without a lathe - as Dan has mentioned: you can make a tool up using a few of the 1st motion nuts welded together with a suitable stud or nut in the end to connect upto the slide hammer.. this tool can then also be used to pull the mainshaft bearing out with the the 'horseshoe' tool between the 1st gear and main bearing.. (rather than hitting the 1st motion end of the main shaft)

the horse shoe tool can be made from a load of the the crank tail 'c' washers - or mdf, nylon (what i use), etc.

regarding locking the box up to undo the relvent nuts - as well as locking it into 1st and 4th.. i also slide revers across: this locks it up good and proper with no lash in the gearset..