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2nd gear end-float and synchro unit


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After cracking the mainshaft on my gearbox a few weeks ago I have been trying to sort out what is good and what needs replacing.

The photo below shows the 2 sets of gears I have, however It has been a game of spot the difference. One has a thrust washer that locates on a ball bearing and the bush for 2nd gear and thrust washer for 3rd gear are one part. Does that mean the end float should be the same on both? Also there is a lot more movement on the synchro hub on the right, you can see the gap in the photo but 2nd gear seems to line up although it is wider.

The only person that can supply the shaft seems to be Mike Papworth but I do not know which thrust washer I will need to use, ball bearing or not?

Another question is which synchro hub should I use? the one on the right has rounded off edges in the first gear direction but the one on the left has a damaged tooth.

Any advice gratefully received.

Alan

gear set.jpg

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Can't offer too much advice on gear selection as I've only every rebuilt the 3-synchro gearbox. The spacing and width of second and third gear would depend on the countershaft cluster, I suspect they beefed up second gear at some point during production? Perhaps one is Dolomite or even Marina... Make sure you check the dog teeth for damage on which ever gear set you end up choosing.

Mix and match the synchro rings. A bigger gap between gear face and synchro ring is usually better as it implies the ridges within are less worn down. They should be pretty sharp:

good_synchro.jpg.99d2edf47dab3fcaf867c81b75045b9d.jpg

And definitely not look like this:
worn_synchro.jpg.cb0542b2d8ef49ee501a4356c2bafb6e.jpg
If you cleanup the rings and gears, you can gauge the friction by pressing the ring against the gear and twisting. You should feel the ring grip the gear (they sometimes screech too). If my notes are correct, somewhere around 35 thou gap is what you should expect.

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from my rebuilds i dont remember a interlock ball on a normal 3rail 4 sync box , but reckon  there is one on a  single rail  and older 3 sync boxes

i  think your thicker 2nd and balled  hub is single rail... all very similar but lots of small non mixable evolution    often reverse on single rail has different tooth count 

good old triumph manuals dont give a baulk ring gap , lots of useless data but little need to now data   but must have a working gap when wrung on to the cone 

is the supply  shortage down to being a 4 sync  3 rail + J  type  ??

pete

 

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Found Mike Papworth very helpful with bits and advice when some teeth broke of the gear cluster in my Vitesse gearbox last year.

Gearbox is three rail fine, single rail, input shaft with J type overdrive, so not one Triumph ever made but all Triumph bit.

Regards

Paul

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