Cam belt tensioners

[Bigxr]

Has anyone had experience of aftermarket cam belt tensioners?
I just changed the belts on mine, and one movable tensioner was seized solid, don't know how long it had been like this, but the belt wasn't too bad, it had just gone all polished and shiny on the rear of it! (and that is after three years and about 15,000 miles since last change).
I couldn't get the bearing off the housing, so I thought, don't bugger about, change the lot.
As the bearings wont come off the holder, I need the housed bearings which look to be a single double-width bearing now, not the double-single bearings as fitted to my bike. Ebay lists kits from Germany around the £180 - £200 mark for the two movable and the two fixed bearings delivered, but they are aftermarket bearings.
Has anyone DIY'd the bearing change, or does everyone just get Luigi to do it!! :mand:

[Albie]

The double bearing ones are £5 each bearing roughly and not cheaply ones I just changed all of mine but the tall tensioner ones were OK. They are the same as the clutch pressure plate ones

[Darkness]

Hi Bigxr: how are things at the dirty castle?
If you read the codes off the bearings you can get SKF or other quality replacements far cheaper than Ducati prices.

[Bigxr]

Hi Albie, the two movable ones are pretty shot, the seized one won't come off at all, and the good one will probably need to be destroyed to release the bearings from the shaft (two days of soaking/bashing and pressing hasn't budged it!). I concluded that the complete thing needs replacing. It would be great if I could get away with just replacing the bearings, but the holder is shot, so I'm biting the bullet and changing the lot.
I was just wondering if anyone had experience of aftermarket kits from ebay.

[Bigxr]

Hey Darkness, Caerfilfy is fine, I need the complete assembly not just the bearings, I wish it wasn't so. :-(

[Albie]

Hi Albie, the two movable ones are pretty shot, the seized one won't come off at all, and the good one will probably need to be destroyed to release the bearings from the shaft (two days of soaking/bashing and pressing hasn't budged it!). I concluded that the complete thing needs replacing. It would be great if I could get away with just replacing the bearings, but the holder is shot, so I'm biting the bullet and changing the lot.
I was just wondering if anyone had experience of aftermarket kits from ebay.

They are a press on fit.. I had to press mine off as the inner must not spin as defeats the object.

[Bigxr]

Yeah, I get that, it would be a nice saving to just change the bearings, but an expensive mistake if the refitted bearings broke down due to my ham fisted attempt at fitting them.
For the record, I've changed lots and lots of bearings bushes etc - most recently rebuilding an ancient Montesa 315R rear linkage and swingarm bushes/bearings which was no picnic, but these tensioner bearings seems a lot more stubborn. They've been in there for 11 years...

[Albie]

No worries I understand
Most may I say that loosely by dealers anyhow but seeing I was doing a complete engine overhaul wanted to try and changed myself

[Bigxr]

My main problem is how to "launder" the cost without her-who-should-be-obeyed finding out!!
(Nice 900 by the way. )

[Albie]

Thanks btw lol. This is just a service cost like your car. It's in the interests of having something devalued or worth more if serviced and running. My missus is ok she believes in me creating good

[BLUNT]

This advice may be too late now but the Clarke bearing pullers from Machine Mart do work well. This is on my M1000 which is same as S2R
As you bolt the two halves together the wedge action initially pulls the bearing along the shaft so the two halves can be closed more and get behind the bearing.
If you do take your bearing to a supplier do make sure the new bearings comply with the SKF suffix 'LHT23' which means the grease is good for up to 150°C
.....and I assume you have removed the circlip?
https://s1.postimg.org/73uovk8hkf/DSCN1579.jpg (https://postimages.org/)
https://s1.postimg.org/1v2cep7nr3/DSCN1580.jpg (https://postimages.org/)

[utopia]

This advice may be too late now ..........

Nope .. never too late.
My 750 is running on 25k old bearings and I intend to change them before it hits 30k.
I shall now be nipping by Machine Mart next time I'm out to pick up one of said pullers.
Ta. :thumbsup:

Having looked at your pics, I might also consider making some kind of centralising button to go between the end of the spigot and the puller bolt.


ps.
I notice they do two sizes .. 30-50mm and 50-75mm.
Which one did you use ?
I'm guessing that the smaller one is big enough ?

[Mr Gazza]

But there are two pullers in use there, aren't there?
A circular one and a three legged one.

I notice that the split circular one has two opposed threaded holes, which look like they could be used with a device much like a clutch cover puller to give a straighter pull. Does something like this come with the puller? Or is one left to one's own invention?

[garry]

how much from the dealers ?

moto rapido quoted £75 for the whole assembly for my evo.

[BLUNT]

I notice they do two sizes .. 30-50mm and 50-75mm.
Which one did you use ?
I'm guessing that the smaller one is big enough ?

You guess right - the 30-50 Part No CHT226 @ £16.99 on a VAT free day.

[BLUNT]

I notice that the split circular one has two opposed threaded holes, which look like they could be used with a device much like a clutch cover puller to give a straighter pull. Does something like this come with the puller? Or is one left to one's own invention?

That would be the way to do it but I already had the 3-leg puller. If not, I would have made a bar to go across and use the tapped holes as you suggest.

Nothing included with the puller but Clarke CHT253 does include all the bits you need although not a good deal @ £69.98 on a VAT free day.

[BLUNT]

I don't think I made it clear that I pulled the bearings off singly - not both together.
https://s1.postimg.org/6v991fungf/DSCN1577.jpg (https://postimages.org/)

[Mr Gazza]

All clear, and thanks.. :thumbsup:

[Bigxr]

Not as neat, clean or shiny, but probably does the same thing. I applied several grunts of pressure to this, plus soaked in releasing fluid for two days, I also tapped the hell out of it in several directions with a small hammer, and still bearing no budge. I could still get the circlip back on if I wanted such was the lack of off-wards movement.
Gave up and placed the order for new; I am now poorer of pocket but calmer of mind.

https://s1.postimg.org/9hl7dvgncv/brng_2.jpg

[BLUNT]

Not as neat, clean or shiny, but probably does the same thing.


Good effort but it does not do the same thing.

If you draw the force diagram for your method and mine you will appreciate the advantage of the wedge where the small input force from clamping the two halves together results in a much larger normal force to move the bearing along the shaft.

Also you are trying to move both bearings together.

[Darkness]

Good effort but it does not do the same thing.

If you draw the force diagram for your method and mine you will appreciate the advantage of the wedge where the small input force from clamping the two halves together results in a much larger normal force to move the bearing along the shaft.

Also you are trying to move both bearings together.

Don't forget about the friction force when drawing your Venn diagram: it might negate the mechanical advantage of the wedge depending on the slope angle of the wedge and how large the "Mew" value [I can't find a Greek alphabet option on the keyboard?].

I also pushed off both together for my Elefant, but used a hydraulic press rather than a vice.

[Dukedesmo]

Cut them off with a cutting disc.

[Darkness]

Cut them off with a cutting disc.

I miss Scrap Heap Challenge on the TV. :chuckle::chuckle:

[BLUNT]

Don't forget about the friction force when drawing your Venn diagram.

Good point and there is some loss due to friction but there is still a mechanical advantage - you could always oil the surfaces, although I didn't.

Even without a mechanical advantage, the wedge of my puller does separate the bearings so they can be removed singly - perhaps that would have worked for Bigxr?

[Bigxr]

The bearings would definitely be easier to remove if separated, and your tool would be useful for doing that if enough force could be applier to separate them, to me though, it looks like separation would be more difficult than removing two together as they look to be fused together. I've recently done some suspension linkages where the two inner bearings had to be removed together, I made a puller using the Heath Robinson method which worked well, but the bearings on this sod have defied all my attempts. Lose the battle to win the war...

[BLUNT]

Fair enough and you're going to fit a new assy now but just out of interest did you try a blowtorch?

[utopia]

Yes, a bit of heat was my first thought.

I'm not so sure that the wedging action gives any particular advantage.
I would guess that the vice method failed due to misalignment, in addition to trying to shift both bearings at once.
ie. if the two stubby spacer/pushers are not matched in length and/or their ends are not square, the force exerted will not be coaxial with the spigot.
Also, the vice jaws themselves are not very flat.
Mind you, I reckon that if I made a single horseshoe shaped pusher/spacer instead of the two stubby ones, the misalignment would be eliminated and there would be a much greater chance of success.
I might even try that now, just out of curiosity
... and get the blowtorch out.

But for £20, Blunt's wedging puller is a snip.

[Bigxr]

I didn't try a blowtorch, the seals will melt and the releasing fluid/grease (if there's any left) will catch fire, but the bearings ar scrap anyway, so maybe I'll keep on trying with these even after I've fitted my expensive shiny new assemblies. If I succeed I can always rebuild with new reasonably priced bearings and sell to recoup some of the fortune spent on new ones!