Propshaft Centre Bearing

[James R]

Hello All.

Looking for some help in confirming the fitting of the prop centre bearing please. I fitted a new speed cable yesterday and whilst underneath noticed that the prop centre bearing isnt secured (no nuts)... I have never had the prop off nor really looked at it to be honest and so I need to check if the issue is just missing nuts OR whether the centre bracket is actually located incorrectly. 3 pictures below to help illustrate show the centre bearing on the outside of the support bracket...

So my question.... Is the propshaft centre bearing located correctly and thus it just needs nuts to hold it to the support bracket
OR
Do the centre bearing lugs need to be underneath the support bracket and then secured?

I cant really tell from the Haynes manual but it looks positioned correctly to me and with that it just needs nuts and securing. If I am correct I assume Loc nuts should be used? If not then I will need to remove and reassemble correctly..

Thanks in advance for any assistance..

[Carledo]

OKAAAAAY! That's a new one on me!

I'm surprised it hasn't fallen off entirely!

The lugs of the centre bearing are supposed to fit above the brackets and have captive nuts in them and the bolts should be fitted from below passing through the brackets and into the captive nust in the bearing housing lugs.

It's possible you have a non OE bearing (correct ones are increasingly unobtainable) that came without captives (or the wrong size ones, there are plenty of these around) but a new nyloc nut and flat washer above will solve that. Alternatively, if it does have 10mm captive nuts, it's perfectly possible to drill the bracket holes out a tad and fit a couple of 1" long 10mmx1 bolts.

HTH, Steve

[James R]

Hi Steve

Thanks very much for the reply and that all made sense.......Until I spoke with a friend about it and he posed the fact that he understood that the early Sprint's was based on the early 1850's and on those cars the centre bearing was below the support bracket not above... He pointed me to a parts catalogue for a look.....

You are one if not the most knowledgeable gent in the club Steve so I don't mean to appear rude or anything, i just want to get it correctly fitted..... So I have a parts listing book from June 1974 RTC9006A that i didn't even think to look at prior to my post.... But it does seem to be drawn that the prop centre bearing is underneath the support bracket secured with a bolt through the top of the support bracket and nut underneath the centre bearing. Interestingly the diagram shows that the bolts that go into the support brackets and screw through the captive nut of the centre bearing have different part codes.. one side is HU806, the other is HU808, so there must be a difference... Would it be length?? I did have a Triumph nuts and bolts catalogue but cant locate it so it would help to know why the different part codes on the bolts...

BTW my centre bearing has captive nuts and does seem ok condition wise so would you think that it would be unsafe if the centre bearing was secured underneath the support brackets? And its safety that is important to me here and also vibration etc.

Thanks Steve...

[Carledo]

No worries James!

It wasn't clear from the pics, nor did you say, that it is a Sprint we are dealing with. So I was right AND wrong simultaneously!

Every other model has both lugs of the centre bearing above the brackets, The manual Sprint ALONE has one above and one below. This is to put a slight angle between the crank/gearbox centreline and the front section of the prop to avoid unwanted harmonic vibrations in the driveline. The normal arrangement is with the drivers side one below the bracket, but you only need one underneath.

If the captives are present and functional then it will be OK without, but it doesn't hurt to put an extra nyloc on the underneath one, I often do!

Should have included that in my first post.

Steve

Edit. Bolts, yes the part number difference is length. But looking at your pics i'd say the originals have already been swapped out for non standard longer ones! I wouldn't sweat over that, happens all the time!

PPS. Never rely on the parts list pictures, they are often misleading!

[James R]

Thanks very much Steve

I have just spent some time searching the forum which I don't find the easiest to be honest, however on this occasion I have found an article that Yorkshire Spam did and also a link to another site, where he kindly shows the centre bearing differences. The manual sprint one is slightly offset in respect of the lugs/captive nuts and so I will try with the one above and one below scenario if my centre bearing is offset. If it’s not then that is a different story!

Club experts are priceless for individuals less experienced...!

Really appreciate the help… Thanks

[Carledo]

Yeah, searching the forum archives can be frustrating, sometimes you have to kiss a load of frogs......... But the Prince is normally in there somewhere! After nearly 30 years in operation there can't be many questions left that haven't been answered.

Unfortunately I don't know enough about computers to know whether it's me or the program and if it IS the program, whether it could be made better or not! Can't be an expert in everything!

Steve

[yorkshire_spam]

I was about to chime in with this: https://sideways-technologies.co.uk/for ... -mounting/

But it seems you already found it!

[Richard the old one]

Is the following any help

https://cdn.triumphowners.com/wp-conten ... pshaft.pdf

[James R]

Thanks all

Appreciate the help and information. Hopefully will get around to looking/fixing this issue at the weekend..

Again thank you!!