3 replies to this topic

[Mite]

My bad if this subject has already been covered in the past, though have not seen much on this aspect of the Mini's history.

 

While the Mini during its development ended up using the A35 synchromesh system instead of the planned Porsche baulk ring synchromesh system, what were the merits of the latter had it been completed in time for the planned launched date of the Mini and how would the Mini have benefited from using such a system?

 

Assuming it was not already used in other BMC / BL cars, could the Porsche Baulk Ring synchromesh system have potentially been utilized in other applications in both Mini-derived and non-Mini cars? Additionally would it have been possible to carry it over to an end-on gearbox configuration or was it likely limited to the in-sump configuration?

 

 

 

 

 

[Spider]

The Porsche System when first introduced, as best I can recall was a Cone Set up, not too different to what the Mini first was fitted with and as used in the Austin A30 and A35 and likely some other models as well.

 

Essentially, the early Mini Gearboxes used, for the most part, Austin A30 Gearsets with 'modified' Input and Outputs shafts, the modification being for the fitting of Input and Output Gears, instead of a Clutch Plate at the front end and a Splined shaft at the back end. The Cone type Synchromesh was satisfactory in these cars for a few reasons;-

 

     The had Gearbox Oil instead of Engine Oil

     The Oil was comparatively kept clean (compared to that in a Mini)

     The Inertia of the Clutch Plate is considerably less than the Clutch Plate and the Drop Gears in a Mini.

 

The Austin A30 also used Bushes for 2nd and 3rd Gears to run on the Mainshaft. This was also initially used in Early Mini Production, but these Bushes burnt out fairly quick due to the type of Lubrication.

 

The move from Cone Type to to a Baulk Ring type Synchomesh was in fact the First Major Design Modification done to the Mini Gearbox and from memory, this was in about 61 or 62. It was costing BMC a small fortune in warranty claims and many were coming back more than once under warranty. The Bushed 2nd and 3rd Gears weren't replaced with Bearings until the 3rd Major Production Change (I think this was late 62 or early 63).

 

I've really no idea what other types of BMC Gearboxes of the day were being fitted with and if any at the time of initial Mini Production, if any others did. I'd say it's quite likely, given their move over to it so soon after production started.

 

The Baulk Ring arrangement certainly was carried over to 'end on' type Gearboxes in the smaller range. I know Morris Minors, Sprites and Midgets (and likely others) all had it, though, I don't know if they all swapped over at the same time or if it was a progressive change.

 

Merits if they had Baulk Ring Syncromesh from the start? Well, a lot less warranty claims for one thing! The other and probably more damaging aspect was that early Minis didn't have the best reputation for longevity nor reliability. No doubt that drove quite a few potential buyers away. Also, remember that upon the Mini first hitting the market, it was a flop that it was seen as too revolutionary and that only made people skeptical that it was all too good to be true - and for it's first few years - it was!  Headaches upon headaches. It's amazing and showed the financial capacity of BMC (at that time) to weather that storm.

 

I'm sure mak01uk and Cooperman can likely add much more here.

 

You may also find some further reading on the Austin Rover On-line website    https://www.aronline...online.co.uk/   while I've found that interesting reading from time to time, I don't know how in depth technically it would get on a subject of History of Mini Gearboxes. While most articles I find quite accurate, there's a few on there that are far from that!  I guess like most internet stuff, you need to do further research.

[DeadSquare]

In the late 50s, certainly in 1960, there was someone in Surrey making a close ratio gear set, with Baulk Rings for Minors, A40s, Sprites etc:

 

I was at still an enthusiastic school boy, driving £5.00, bald tyred, wandering steering jalopies,  ( soon to be condemned by the new MOT ),  who dreamed of owning and hotting up a 948cc Morris Minor, and I didn't understand what the extolled "Baulk Ring" meant.

 

Yes, the Mini was a bit of a flop when it was launched, but that was because the hole it was meant to fill, had been filled by Harold Macmillan's "You've never had it so good" financial boom, so who wanted to be seen in what a lot of people thought of as  "A Bubble Car".

 

Three things helped the Mini on its way:-..........

 

Easing the Hire-purchase rules meant that a new purchase-tax free Mini van was an affordable first vehicle.

 

Harold Wilson stuck 6 d on petrol, up from 4/6 to 5/-   ( that is 2 1/2P, up from  22 1/2P to 25P, per gallon  )

 

Peter Sellers, a car enthusiast, found a Mini to be jolly handy in London.  However, ( Don't say "Photo, or it isn't true" ), it was when he 'had' Princess Margaret in the front of his Mini, that she bought one, and thanks to the press snapping her driving it, what was good enough for royalty, became good enough for commoners.

[Mite]

The Porsche System when first introduced, as best I can recall was a Cone Set up, not too different to what the Mini first was fitted with and as used in the Austin A30 and A35 and likely some other models as well.

 

Essentially, the early Mini Gearboxes used, for the most part, Austin A30 Gearsets with 'modified' Input and Outputs shafts, the modification being for the fitting of Input and Output Gears, instead of a Clutch Plate at the front end and a Splined shaft at the back end. The Cone type Synchromesh was satisfactory in these cars for a few reasons;-

 

     The had Gearbox Oil instead of Engine Oil

     The Oil was comparatively kept clean (compared to that in a Mini)

     The Inertia of the Clutch Plate is considerably less than the Clutch Plate and the Drop Gears in a Mini.

 

The Austin A30 also used Bushes for 2nd and 3rd Gears to run on the Mainshaft. This was also initially used in Early Mini Production, but these Bushes burnt out fairly quick due to the type of Lubrication.

 

The move from Cone Type to to a Baulk Ring type Synchomesh was in fact the First Major Design Modification done to the Mini Gearbox and from memory, this was in about 61 or 62. It was costing BMC a small fortune in warranty claims and many were coming back more than once under warranty. The Bushed 2nd and 3rd Gears weren't replaced with Bearings until the 3rd Major Production Change (I think this was late 62 or early 63).

 

I've really no idea what other types of BMC Gearboxes of the day were being fitted with and if any at the time of initial Mini Production, if any others did. I'd say it's quite likely, given their move over to it so soon after production started.

 

The Baulk Ring arrangement certainly was carried over to 'end on' type Gearboxes in the smaller range. I know Morris Minors, Sprites and Midgets (and likely others) all had it, though, I don't know if they all swapped over at the same time or if it was a progressive change.

 

Merits if they had Baulk Ring Syncromesh from the start? Well, a lot less warranty claims for one thing! The other and probably more damaging aspect was that early Minis didn't have the best reputation for longevity nor reliability. No doubt that drove quite a few potential buyers away. Also, remember that upon the Mini first hitting the market, it was a flop that it was seen as too revolutionary and that only made people skeptical that it was all too good to be true - and for it's first few years - it was!  Headaches upon headaches. It's amazing and showed the financial capacity of BMC (at that time) to weather that storm.

 

I'm sure mak01uk and Cooperman can likely add much more here.

 

You may also find some further reading on the Austin Rover On-line website    https://www.aronline...online.co.uk/   while I've found that interesting reading from time to time, I don't know how in depth technically it would get on a subject of History of Mini Gearboxes. While most articles I find quite accurate, there's a few on there that are far from that!  I guess like most internet stuff, you need to do further research.

 

I see, from the articles that did mention it was under the mistaken impression Porsche Baulk Ring Syncromesh never reached the Mini as opposed to appearing later in the early-1960s.