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sparrowcycles

JP3 Blackstone box bearings.

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Hey folks, I've recently had my gearbox and reduction box off for some work and I've found that a good few of the bearings are pitted or worn, I'm planning on changing the lot but thought I'd ask whether anyone knows a good supplier for them (ideally from a normal bearing supplier rather than with added boat tax on top) 

 

I'm aware that, the reduction box thrust bearing is the pricey one, has anyone had any luck finding a supplier for them? 

 

Thanks all! 

 

S

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Bearing Boys, whatever Fenner are called these days or your local bearing merchant.   Imperial bearings are less common these days, so you may have a wait, but they are generally available.  They are dimensioned by type,  OD, ID and width  and come in various grades of precision.  Take the old ones in if you can.   Do not worry if the new ones come with rubber seals (2RS at the end of the number) or with shields (ZZ).  Just flip them off with a small screwdriver.

Try to avoid the cheap Chinese ones and go for good Chinese ones like SKF.

N

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1 hour ago, sparrowcycles said:

Hey folks, I've recently had my gearbox and reduction box off for some work and I've found that a good few of the bearings are pitted or worn, I'm planning on changing the lot but thought I'd ask whether anyone knows a good supplier for them (ideally from a normal bearing supplier rather than with added boat tax on top) 

 

I'm aware that, the reduction box thrust bearing is the pricey one, has anyone had any luck finding a supplier for them? 

 

Thanks all! 

 

S

When I rebuilt my reduction box 30 years ago, the cost of the thrust bearing was eye watering, even then. I was advised to use an ordinary bearing instead, as I have a plummer block on my propshaft which takes the thrust from the prop. That system seems to have worked OK so far. Do you have a plummer block fitted? If you don't, it may be worth exploring the possibility of installing one. It may work out cheaper in the long run. My boat is 70ft with a JP2 by the way.

Edited by monkeyhanger
Addition of words

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I’ve recently had great service from Leicester Bearings. The have sources some obsolete FAG units for me. 
 

It would help if you could take the old units into any bearing supplier...I agree the reduction box Thrust bearing isn’t cheap...mind you one of my FAG Plummer block bearings was over £100 with a new taper lock etc. excluding the housing....

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Thanks folks, I'll have a look and check if my plummer block is also a thrust bearing, if it does that would save a lot of hassle and money! 

 

I'll check out those suppliers once I know! 

 

Thanks again, I really appreciate it. 

S

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Can I ask a Q?

My coupling seems to have a threaded hole in the casing, is this normal?

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Just now, LadyG said:

Can I ask a Q?

My coupling seems to have a threaded hole in the casing, is this normal?

Can you post a picture?? Bit confused as to where you mean??

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8 minutes ago, LadyG said:

Can I ask a Q?

My coupling seems to have a threaded hole in the casing, is this normal?

Do you have a JP3 with a blackstone box, Jo?

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9 minutes ago, OptedOut said:

Grub screw hole?

I am not sure what that is, but yes, perhaps

8 minutes ago, TheBiscuits said:

Do you have a JP3 with a blackstone box, Jo?

nope

 

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14 minutes ago, OptedOut said:

A coupling with a grub screw hole, usually drilled over any keyway the coupling may have. It is provided to stop axial movement along the shaft.

 

https://www.midlandchandlers.co.uk/products/r-d-4-split-half-coupling-1-1-2-shaft-rd202153f

OK, so it not always needed , as in this instance?

{'m not sure anyone wants axial movement, [is this "creep"along shaft]

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OK so I've finally got the time to look at and order some bearings for the gearbox and reduction. 

 

My eyes did water when looking at the price for the gearbox thrust bearing! Blimey! 

However when looking at the parts list it seems that bearing is only specified for direct drive only, which makes sense as no thrust would get transferred through the reduction box. 

 

Then the reduction box diagram has its own, normal, ball bearing on the diagram which I believe would replace the thrust bearing of the gearbox end plate. 

 

Thankfully sleeman and hawken seem to have the reduction box thrust bearing for a little over £60 so I'm happy with that but I thought I'd ask here in case I've made a schoolboy error and not seen it. 

 

Thanks! S

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32 minutes ago, sparrowcycles said:

OK so I've finally got the time to look at and order some bearings for the gearbox and reduction. 

 

My eyes did water when looking at the price for the gearbox thrust bearing! Blimey! 

However when looking at the parts list it seems that bearing is only specified for direct drive only, which makes sense as no thrust would get transferred through the reduction box. 

 

Then the reduction box diagram has its own, normal, ball bearing on the diagram which I believe would replace the thrust bearing of the gearbox end plate. 

 

Thankfully sleeman and hawken seem to have the reduction box thrust bearing for a little over £60 so I'm happy with that but I thought I'd ask here in case I've made a schoolboy error and not seen it. 

 

Thanks! S

Pretty sure when my gearbox & reduction box was rebuilt a thrust bearing was only fitted on the reduction box. Mind you I then have a UJ with another thrust bearing just before the stern tube.

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48 minutes ago, sparrowcycles said:

OK so I've finally got the time to look at and order some bearings for the gearbox and reduction. 

 

My eyes did water when looking at the price for the gearbox thrust bearing! Blimey! 

However when looking at the parts list it seems that bearing is only specified for direct drive only, which makes sense as no thrust would get transferred through the reduction box. 

 

Then the reduction box diagram has its own, normal, ball bearing on the diagram which I believe would replace the thrust bearing of the gearbox end plate. 

 

Thankfully sleeman and hawken seem to have the reduction box thrust bearing for a little over £60 so I'm happy with that but I thought I'd ask here in case I've made a schoolboy error and not seen it. 

 

Thanks! S

That price seems reasonable. I was quoted £57 in 1989! (Hence not buying)

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