Acceptable play in V50 ujoint?

[jamesfjamesf]

HI all..I'm refreshing an 81 V50 III (details on the rebuild forum) and the ujoint has the slightest click if I twist it against itself, i.e. like it would experience under acceleration/deceleration. In my inexperience, no play should be allowed. It feels like the same clearance an intake valve would have. Just enough to feel. I also think a click indicates a lack of lubrication. The bike has 30k miles and has been decently maintained but I doubt the ujoint has been disassembled for regreasing.

Should I bother regreasing or is this too much play?

thanks,
jim

[Frenchfrog]

I'd replace it.Had one explode on me many years ago and it was not a pleasant experience at all.Plus with the small bloc gearboxand swinging arm being alloy  you risk taking out the back of the box too which would possibly make the bike a scraper.That happened on a friends V65 and she never rode a bike again she was so scared.

[Tusayan]

It feels like the same clearance an intake valve would have.

Should I bother regreasing or is this too much play?

That’s a lot of clearance. It should have zero as you correctly understand and it should not be put back into service.

[Dirk_S]

I was going to offer the comfort and assurance that at least most small blocks have used the same driveshaft from the 70s all the way through to the V7 III, but looking at the parts fiche, I see the V50 III and PA version use part # GU19328021, whereas the clear majority use # GU23328081, of which you can often find lightly used ones on ebay. Wonder where the differences lie.

[Frenchfrog]

The spline count on the gearbox output shaft is my guess.Early smallblocs have a different count almost right through every shaft in the box.Those models went through a hell of a lot of updates compared to big blocs.

[jamesfjamesf]

On further inspection I discovered the most play was actually side to side on the gearbox yoke side-  between the end cap and its circlip. Maybe it was replaced/serviced and someone reefed on it in when reassembling?

The driveshaft yoke's bearing surfaces were dry and and a bit marred though I couldn't feel any surface imperfections.

Charlie from  Antietam Classic Cycle said he successfully used http://www.theujointstore.com/tus1m1.html as a replacement. It's suspiciously cheap at $28 but I'll give it a go :-)

jim

[Antietam Classic Cycle]

On further inspection I discovered the most play was actually side to side on the gearbox yoke side-  between the end cap and its circlip. Maybe it was replaced/serviced and someone reefed on it in when reassembling?

The driveshaft yoke's bearing surfaces were dry and and a bit marred though I couldn't feel any surface imperfections.

Charlie from  Antietam Classic Cycle said he successfully used http://www.theujointstore.com/tus1m1.html as a replacement. It's suspiciously cheap at $28 but I'll give it a go :-)

jim

Yes, used that several times. Very good quality and as far as I know, durable.

[Pescatore]

On further inspection I discovered the most play was actually side to side on the gearbox yoke side-  between the end cap and its circlip. Maybe it was replaced/serviced and someone reefed on it in when reassembling?

The driveshaft yoke's bearing surfaces were dry and and a bit marred though I couldn't feel any surface imperfections.

Charlie from  Antietam Classic Cycle said he successfully used http://www.theujointstore.com/tus1m1.html as a replacement. It's suspiciously cheap at $28 but I'll give it a go :-)

jim

Hey Jim, I see the only specs on the TUS-1MG are  20x44mm.
That website shows two different sizes available.
Is that width/length, caps diameter?
Is that what your cross measures?
Just wondering how to identify what I need on a similar bike?
.

[Antietam Classic Cycle]

Hey Jim, I see the only specs on the TUS-1MG are  20x44mm.
That website shows two different sizes available.
Is that width/length, caps diameter?
Is that what your cross measures?
Just wondering how to identify what I need on a similar bike?
.

20 mm is the diameter of the bearing cap, 44 mm is the width of the "cross" with caps. 

[huub]

if you find a shop specialised in agricultural equipment, the bearings are cheap ( around 10 euro)
https://www.amacoo.nl/kruisstuk-20x44-by-py-05-41

[jamesfjamesf]

The ujointstore.com part came in today, and while the size is correct (44mm end to end), the caps aren't as deep as the original, meaning there is less bearing. I don't like it one bit but maybe I'm overreacting? Charlie, were the ones you used from them similarly shortened?

I'm surprised this measurement isn't part of the spec.

jim

[Antietam Classic Cycle]

The ujointstore.com part came in today, and while the size is correct (44mm end to end), the caps aren't as deep as the original, meaning there is less bearing. I don't like it one bit but maybe I'm overreacting? Charlie, were the ones you used from them similarly shortened?

I'm surprised this measurement isn't part of the spec.

jim

The rubber seal covers part of the bearing, the needles are the same length - at least they were on the ones I've installed. I did need to reuse the old circlips in order for them to fit.

[jamesfjamesf]

The rubber seal covers part of the bearing, the needles are the same length - at least they were on the ones I've installed. I did need to reuse the old circlips in order for them to fit.

After posting this I thought to measure the bearings. A very crude measurement (I didn't remove them, just stuck the caliper depth gauge in there) showed the old ones were 11mm, the new ones 10mm. I think the thickness of the top of the caps is also greater in the old ones, giving an illusion of a lot less bearing space.

The circlips that came with mine (new batch perhaps, since he was out for a while) were 1mm thick, same as the old ones, and worked fine.

jim