4 Sync Gearbox Syncho/Baulk rings

Hi,

I am rebuilding my gearbox and have a question for all the gearbox experts. Its a 4 syncho gearbox.
There are 2 types of baulk rings fitted when the gearboxes where originally made. The 3/4 baulk ring is shown on the left and the 1/2 ring on the right.

Why where they different? Looking at them it looks like the 3/4 ring with the extra ramp would help the synch go in.

It looks like you can only buy the 1/2 type new, and have to fit this in the 3/4 position. Is the 1/2 now only supplied to make stock control easier, over the years it has been found better to use the same ring in both places?

I have enough of both types of rings to rebuild the gearbox with either rings in either positions.

The gearbox gets used in a race car so any advantage is worth while.

As far as I can tell the rings are interchangeable. As to whether one or the other would be better suited to race conditions I can't tell you.

Jack

From what I have heard, and Kelvin enlighten us with more information if you know it, Moss is in motion to have more sychro's made. The timeline is unknown to me. I also know that there is an outfit that is building them from the CNC machine at around $100 each, but I don't have their bookmark on this computer.

I think that someone (Kelvin ?) said that originally they were different materials. But only one is available now. I've always wondered about that.

I believe that they are back in production now.

Thanks for the replies.

I guess I'll put it back with the rings as they were originally designed.

James

- they are all spec same now

yes they are sometimes different oem per picture above

i have boxes apart right now - from '68 to '78 - rings are of inconsistent design across years - some have more oil bleed grooves, but that feature is not consistent across even those which are identifiable as 1-2 vs 3-4 per the old factory manual - - as near as i can tell the difference is only cosmetic - who knows why?


2 days ago I got a note from MOSS UK that they now have 'em in stock again - all 4 same part number - about PoundsSterling 20 each

called Moss USA - not in stock yet - no shipments coming til March 30

get 'em while ya can - unless made 10,000 of 'em, they won't last long


2 weeks ago i paid $450- for a set of 4 from australia - Kanda Engineering - the only ones on the market for the last year

and they are on eBay for $40 each used - you won't know the clearance until you buy & trial fit



Larry

here is a picture of your worst case - split at dog-ear

another pic - new vs used

3rd pic - new vs new_Kanda

as Chris writes elsewhere - if you have it apart and the rings measured half or less than new spec (about .060) - it is false economy to put the old rings back in