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cryrnr
United Kingdom
214 Posts |
 Posted - 09/05/2014 : 10:02:46
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| I have asked Mike Dowley (Sports & Vintage) about the possibility of making close ratio gear kits (i.e. 1st & 2nd gears to PB ratios plus selectors etc.) for the PA. S & V have produced these in the past but understandably Mike is reluctant to commission another batch unless he knows there is demand. He tells me the minimum would be 10 sets. Knowing how much demand there is for PB 'boxes I would hope there would be sufficient interest to persuade Mike this would be a viable project. If you are potentially interested could I encourage you to contact me and/or post here. Thanks, Neil. |
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Oz34
United Kingdom
2542 Posts |
Posted - 09/05/2014 : 11:17:48
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I would definitely be interested at least in knowing a price based on 10 sets.
If only 1st & 2nd are involved, PB owners with worn gears could perhaps take advantage which would increase the market. Also presumably PAs could stick with their existing 1st motion shafts?
Dave |
Edited by - Oz34 on 09/05/2014 11:22:03 |
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MaGic_GV
United Kingdom
868 Posts |
Posted - 09/05/2014 : 12:05:41
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As one who converted his PA to PB ratios some years ago, I heartily recommend the change - improves driveability no end!
Regards,
Graham
ps would these gears fit N types as well? |
Edited by - MaGic_GV on 09/05/2014 12:06:30 |
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George Eagle
United Kingdom
3240 Posts |
Posted - 09/05/2014 : 12:21:17
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Hi Graham
As far as I am aware the gear sets will be ok for the N types as well.
My old NB came with PA ratios in what I believe was the original gearbox and I fitted a PB gearbox. The improvement is well worth while.
George
l 2023 |
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MaGic_GV
United Kingdom
868 Posts |
Posted - 09/05/2014 : 16:47:02
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quote:
Originally posted by Oz34
Also presumably PAs could stick with their existing 1st motion shafts?
Dave
Not so I'm afraid, these differ between gear sets - at least the PA is different to the PB version...
Regards,
Graham
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Edited by - MaGic_GV on 09/05/2014 16:48:53 |
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Oz34
United Kingdom
2542 Posts |
Posted - 09/05/2014 : 19:48:54
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Displaying my ignorance Graham. I thought the difference was internal/external dogs for top gear?
Confused......as ever!
Dave |
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George Eagle
United Kingdom
3240 Posts |
Posted - 09/05/2014 : 19:53:43
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As I understand it the replacement gears are for fitting to a PA box which is common to the NA and any NB fitted with the PA ratios.
The internals for the PB box are completely different to the PA box.
George
L2023 |
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Hornet
United Kingdom
382 Posts |
Posted - 09/05/2014 : 21:10:15
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| first motion shaft has a different amount of teeth hence different ratios, not just internal or external dog engagement . ration for constant mesh third is different , as to are the drive dogs for third to top . different ratios could be made for second gear but first would have to remain the same as it has to mesh with 1st . |
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pauly45
United Kingdom
435 Posts |
Posted - 10/05/2014 : 07:33:22
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Excuse my complete ignorance on this, but if you have a standard PA box, what other bits do you need to do the swap to PB ratios using the 1st and 2nd gears proposed here?
Just a 1st motion shaft??
And that would be a PB one?
Paul |
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Andrew Fock
Australia
374 Posts |
Posted - 10/05/2014 : 09:23:06
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My understanding is that 1st and 2nd remain the same and it is the constant mesh and third that are changed. Because of this the third (?) gear selector also needs to be changed. The expense is because the gears that need changing are herringbone ones.
I would also put my hand up for a set.
regards,
Andrew
NA 0279
PA 1294
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Colin Butchers
United Kingdom
1487 Posts |
Posted - 10/05/2014 : 09:50:37
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I would also be interested in having set - but it will all depend on price.
Count me in on a provisional basis.
Colin B. |
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Dan F
USA
845 Posts |
Posted - 10/05/2014 : 10:51:24
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I'd be interested in knowing the price as well. Perhaps it's time for a run of 1st motion shafts as well ?
Best
Dan |
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John Reid
United Kingdom
704 Posts |
Posted - 10/05/2014 : 11:41:07
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To clarify (hopefully ) the comments made on the differences between PA and J2/PB gear ratios and the position of the dogs, here is a photo of the gears from Aramis, which has J2/PB ratios and a PB input shaft.
The corresponding teeth on a PA box are:
20 24 31 38
33 29 22 15 layshaft
Also the selectors are different between PA and PB.
John R
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Peter Green
United Kingdom
1682 Posts |
Posted - 10/05/2014 : 14:52:29
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To add to John's comments the L type gearbox ratios are the same as the J and PB ratios but the input shaft is longer than the J but shorter than the PB input shafts.
Peter. |
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MaGic_GV
United Kingdom
868 Posts |
Posted - 10/05/2014 : 17:58:10
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Regret I can add little more as I used a PB gearbox, which came without first motion shaft, which I acquired new, but I can confirm that this part in PA differs from PB!
Regards,
Graham
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cryrnr
United Kingdom
214 Posts |
Posted - 10/05/2014 : 22:27:11
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Many thanks to everyone who has responded to my original posting. The information provided has been most illuminating and its encouraging that even at this early stage there looks to be interest (subject to price of course) in a close ratio gear set for the PA.
Whilst I've previously rebuilt an ENV 'box the Wolseley type is new to me so I'm on a steep learning curve. I will clearly need to go back to Mike Dowley for more detail as to how S&V achieved the close ratio conversion. The most obvious route of new 1st and 2nd gear pairs is probably not practical as; 1) any change in the 1st gear size would necessitate a new reverse idler and 2)the 1st and 2nd input gears are machined integral with the layshaft. This is presumably the reason the conversion involves the, more expensive to manufacture, constant mesh 3rd pair and input pair (i.e. 1st motion shaft with its integral gear and the matching constant mesh gear that drives the layshaft). Assuming this is indeed the case (see post by Andrew Fock) it raises an interesting question about the final gear ratios which I suspect won't be identical to the PB but may in fact be better!
My logic is as follows; obviously a gear can only have an integer number of teeth but where the distance between the axes of a gear pair (i.e. the distance between the centre lines of the mainshaft and layshaft) and the diametrical pitch ('imperial' measurements - effectively tooth size, module is the equivalent measure in the metric system) are already fixed (by the designers at Wolseley)this limits the number of possible teeth combinations. For this reason I wouldn't be at all surprised to find that the S&V conversion sticks with the PB teeth numbers (I will try and check with Mike on Monday) - i.e. 22/31 for the input pair and 27/26 for sliding 3rd pair (see John Reid's post).
Combining these with the existing PA 1st and 2nd gears I calculate this gives gearbox ratios of 3.57, 1.99, 1.37 and 1 (PB ratios are 3.57, 2.14, 1.36 and 1). In other words 2nd gear would be higher than the PB and all others identical. This means the ratios in 2nd, 3rd (and top of course) would be the same as in the much vaunted ENV 'box as used in the F-type and C-type (and close to those in the J4) but with the advantage that 1st gear is higher (4.02 with the standard ENV gear set which most consider too low).
Apologies for rambling on but if I'm correct in my assumptions - if anyone knows better/different I'd be delighted to know more - then conversion of a PA 'box based on new constant mesh 3rd & 1st motion/input gear pairs with PB ratios looks to offer an even better option than a PB 'box (assuming you can find one and sort the various different conversion issues). Hopefully this might prompt even more interest. Can't wait to find out from Mike if I'm correct!
Neil |
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