Universal Joint fitting

I have fitted UJs into their carrier bearings in the past using a mallet. Tricky to hold straight but I have fitted 3 which have all been going for years.
Someone just told me it mustn’t be done with a hammer but a special tool. I’m about to fit a UJ…
I have a workshop manual, a Haynes manual and the inter web but nowhere are there instructions on how to fit.
Any views?
Anyone shocked and aghast at my neanderthal methods don’t shoot.

Most of my UJs have been a loose fit which I’ve then had to Loctite to the carrier bearing. Banging the UJ into that bearing could cause damage to the bearing of course.

When I did fit a new UJ it was tight. It broke my heart to do it, but I mounted it up on a lathe and polished it with fine emery to a good fit.

BTW - I usually put the UJ on the g/box output shaft first and then offer up the s/arm to plug onto the UJ. I find it easier that way, but does that preclude any malleting prior.

My Spada one just dropped out and also had to be fitted with some bearing fit to keep it in there.
I checked the one on my Cali last week and that was tight in the bearing so left it in place as it felt solid.

ha, second one with a loose fit, I believe they should be an interference fit - the bearing should turn not the UJ…

When they’re new they’re an interference fit, when they get old they are sloppy and loose and need to be Loctited when put back in. Which will just go loose again. This is why I am a bit amused when I read about people rebuilding the needle roller bearings, jolly good show, but what about the end bit that’s now loose? Also the splines wear


While it’s possible to tap a new support bearing into the swingarm tube on its outer race, I don’t know of any special tool to put the UJ yoke in. I did it with a long soft drift I think, a little bit at a time gently on each side, on the parts of the rear yoke that you can get at. This means tapping on the inner race, but, whaddya do …

Apart from that new UJ all the others I’ve worked with have been loose. I don’t know why this should happen - obviously this leads to the possibility of it spinning in the bearing inner and then exacerbating the problem.

I pulled the arm off Blue last week expecting to be applying Loctite at that point but in fact the UJ was still tight. So I reassembled without disturbing it.

I have heard that on rebuild you can have the other end of the UJ machined to give a good fit into the bearing and hence a second bite of the cherry, so to speak.

You can buy ‘‘U Joint Press Tool’’, plenty of choice with youtube videos

You haven’t done this have you? Most of those are for extracting and replacing the needle roller bearings. That isn’t the problem. The problem is extracting and replacing the entire assembly in the swingarm driveshaft tunnel. It’s a virtually blind hole, there’s no room to get a tool in there. Except something to hit a hammer with.


Why bother doing this there are firms out that will source the bearings and fit them for you P and j prop shafts in Hillington ind estate Glasgow used to do all of mine there must be few places down south also ?

I’ve always used the Eddie Reed/OME method: put the UJ in the freezer for a few days, and the swinging arm in the airing cupboard.

For the same reasons as any other DIY jobs - saves money, because you enjoy it, don’t want others working on your bike etc.
I’ve done 2 UJ rebuilds. Not very difficult, although the smaller ones on loops are a bit more fiddly.