28 replies to this topic

[gaspen]

Hello

 

I hope I can explain my question clearly 

 

Is there any data for manufacturing tolerance of the primary gear ? I mean the concentric accuracy of the gear/sealing surface/clutch disc ribs compared to the bush diameters.

 

I heard about a whispering that the scrap pieces from the factory became NOS parts after a while. That is why I would like to measure my gears.

 

 

 

 

[Spider]

Sorry this isn't a great copy, but I think you'll be able to see what you need to

 

 

[Lplus]

Hello

 

I hope I can explain my question clearly 

 

Is there any data for manufacturing tolerance of the primary gear ? I mean the concentric accuracy of the gear/sealing surface/clutch disc ribs compared to the bush diameters.

 

I heard about a whispering that the scrap pieces from the factory became NOS parts after a while. That is why I would like to measure my gears.

I suspect that concentricity would depend on the accuracy of the lathe on which the bushes were machined.  Even if the inner surfaces of the gear were eccentric to the outer surfaces that error would be eliminated when the gear was gripped by the lathe jaws and the inner bush machined.  I doubt there would be any specified tolerances for the acccuracy of the lathe.

[gaspen]

Sorry this isn't a great copy, but I think you'll be able to see what you need to

 

 

 

The copy is fine but that's not what I am looking for.

 

I need the "circle-tolerance" compared to the centerline of the gear. I mean : if I rotate the gear around the centerline of the bushes, how much would be the "roundness" tolerance of the outer parts. Is it clear ?

 

 EUuv0nt.jpeg   93.48K   4 downloads

[Spider]

The copy is fine but that's not what I am looking for.

 

I need the "circle-tolerance" compared to the centerline of the gear. I mean : if I rotate the gear around the centerline of the bushes, how much would be the "roundness" tolerance of the outer parts. Is it clear ?

 

Reading the notes on the drawing, while it doesn't give a figure for run out it does say 'Concentric' which from other factory tolerances for other gears is less than 1/10 of a thousandth.
 

Edited by Spider, 18 November 2022 - 11:27 PM.

[gaspen]

 

The copy is fine but that's not what I am looking for.

 

I need the "circle-tolerance" compared to the centerline of the gear. I mean : if I rotate the gear around the centerline of the bushes, how much would be the "roundness" tolerance of the outer parts. Is it clear ?

 

Reading the notes on the drawing, while it doesn't give a figure for run out it does say 'Concentric' which from other factory tolerances for other gears is less than 1/10 or a thousandth.
 

 

 

I guess it is 0.001" (inch) , right ? Sorry, I am living in a metric country 

[Spider]

 

 

The copy is fine but that's not what I am looking for.

 

I need the "circle-tolerance" compared to the centerline of the gear. I mean : if I rotate the gear around the centerline of the bushes, how much would be the "roundness" tolerance of the outer parts. Is it clear ?

 

Reading the notes on the drawing, while it doesn't give a figure for run out it does say 'Concentric' which from other factory tolerances for other gears is less than 1/10 or a thousandth.
 

 

 

I guess it is 0.001" (inch) , right ? Sorry, I am living in a metric country 

 

 

Sorry, no. It's < 0.0001"  or 0.0025 mm

[gaspen]

I see, thank you !

[T.Harper]

 

The copy is fine but that's not what I am looking for.

 

I need the "circle-tolerance" compared to the centerline of the gear. I mean : if I rotate the gear around the centerline of the bushes, how much would be the "roundness" tolerance of the outer parts. Is it clear ?

 

Reading the notes on the drawing, while it doesn't give a figure for run out it does say 'Concentric' which from other factory tolerances for other gears is less than 1/10 or a thousandth.
 

 

Spider - did you mean 10 of a thousandth?  I think so and then that would all make sense ! 

[Spider]

 

 

The copy is fine but that's not what I am looking for.

 

I need the "circle-tolerance" compared to the centerline of the gear. I mean : if I rotate the gear around the centerline of the bushes, how much would be the "roundness" tolerance of the outer parts. Is it clear ?

 

Reading the notes on the drawing, while it doesn't give a figure for run out it does say 'Concentric' which from other factory tolerances for other gears is less than 1/10 or a thousandth.
 

 

Spider - did you mean 10 of a thousandth?  I think so and then that would all make sense ! 

 

 

Yes !

My bad and thanks !

[gaspen]

Ok now I know the tolerance but how should I measure it ? 

[Lplus]

Ok now I know the tolerance but how should I measure it ? 

Put it in a lathe and use dial guages on inner and outer surfaces? 

 

I'll be honest and ask why you are worried about the state of the primary gear - are you having problems?   I realise you're worried about a rumour of poor quality, but unless you have problems it seems a lot of trouble to go to.

[gaspen]

 

Ok now I know the tolerance but how should I measure it ? 

Put it in a lathe and use dial guages on inner and outer surfaces? 

 

I'll be honest and ask why you are worried about the state of the primary gear - are you having problems?   I realise you're worried about a rumour of poor quality, but unless you have problems it seems a lot of trouble to go to.

 

 

When I rebuilt the engine, I've purchased silicone based bushes to the primary gear. The p/g now runs with those bushes. These were machined of course. Now I learnt that silicone bushes are scrap. Fortunately I drove very few kilometers.

 

Some weeks ago I've purchased some NOS gears for 45 EUR each : one for replace and four for spares. I want to install one of them, but I heard about this rumour.

 

Against the rumours : the gears I've bought was packed in the original paper box with greaseproof paper... 

 

 20221018_191504 (1).jpg   46.63K   4 downloads

[Lplus]

 

 

Ok now I know the tolerance but how should I measure it ? 

Put it in a lathe and use dial guages on inner and outer surfaces? 

 

I'll be honest and ask why you are worried about the state of the primary gear - are you having problems?   I realise you're worried about a rumour of poor quality, but unless you have problems it seems a lot of trouble to go to.

 

 

When I rebuilt the engine, I've purchased silicone based bushes to the primary gear. The p/g now runs with those bushes. These were machined of course. Now I learnt that silicone bushes are scrap. Fortunately I drove very few kilometers.

 

Some weeks ago I've purchased some NOS gears for 45 EUR each : one for replace and four for spares. I want to install one of them, but I heard about this rumour.

 

Against the rumours : the gears I've bought was packed in the original paper box with greaseproof paper... 

 

20221018_191504 (1).jpg

 

Presumably you mean silicone bronze bushes.  Have they actually failed? or do you mean you have since learned that silicone bronze is not suitable?

 

That's a lot of spares for one engine.  Apart from the corrosion on one of them they look just fine.

[gaspen]

 

 

 

Ok now I know the tolerance but how should I measure it ? 

Put it in a lathe and use dial guages on inner and outer surfaces? 

 

I'll be honest and ask why you are worried about the state of the primary gear - are you having problems?   I realise you're worried about a rumour of poor quality, but unless you have problems it seems a lot of trouble to go to.

 

 

When I rebuilt the engine, I've purchased silicone based bushes to the primary gear. The p/g now runs with those bushes. These were machined of course. Now I learnt that silicone bushes are scrap. Fortunately I drove very few kilometers.

 

Some weeks ago I've purchased some NOS gears for 45 EUR each : one for replace and four for spares. I want to install one of them, but I heard about this rumour.

 

Against the rumours : the gears I've bought was packed in the original paper box with greaseproof paper... 

 

20221018_191504 (1).jpg

 

Presumably you mean silicone bronze bushes.  Have they actually failed? or do you mean you have since learned that silicone bronze is not suitable?

 

That's a lot of spares for one engine.  Apart from the corrosion on one of them they look just fine.

 

 

I heard some horror story about silicone-bronze bushes, that is why I want to replace the gear. I will be more peaceful with the Deva-bushed gear.

 

2 of 5 will be mine, my friend purchased 3. That is just surface corrosion, apart from that there is no sign of any wear on them.

 

 

 20221120_154639.jpg   43.13K   0 downloads