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750 Sprints, Spider, 101 Sprint, Spider & Ti, 105 Sprint GT, 105 Juniors, others
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Hi Robert et al

Thanks for the info & the tip on fixing the 1st gear crunch, I've just done this to the early split case I rebuilt for Dad's Giulietta Spider and the result is as described.

Thanks for sharing with the rest of us, wish I'd known about this 20 years ago, the BB is a GREAT resource !!!

Ciao
Greig
Sunny South Africa
 

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different synchro mechanisms

Hello, I am currently rebuilding a 101 5 speed split case gearbox. After removing the synchros, I found out the the internals are different w.r.t. later boxes.

The first picture shows the 1st gear mechanism for an earlier box, and the second for a later box (the dog gear is broken, I had to grind it to get it off the gear).Also the arc is longer on the earlier model.
 

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2nd-5th gears show a similar difference. The first pic is of an earlier model, and the second of a later model (on top of the earlier model). Again, the arcs of the earlier model are larger.

I am planning to do the first gear fix, while keeping the original dog gear (I did this also on my GTV, and it has been working excellent over the last 2 years.

Questions:
-any reasons alfa modified the interanls of the synchros?
-which one is better? Should I upgrade gears 2-5 to later model, or keep original?

Needless to say that the 101 box came with the first generation synchros; those with the circular patterns.

Greig: I just read that you did a similar thing on a 101 splicase box. Did you notice this, and what did you do?
 

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Discussion Starter · #128 ·
You may also fond the syncro ring itself is different. Early syncros were a dull light-grey with grooves around the ring; later ones were a rough-looking dark ring, looking almost nodular. Richard Jameson says the earlier rings were better.

Robert
 

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After some careful reading in different parts manuals I found out that the older style internals are for non-moly synchros, whereas the newer style ones for moly synchros.

Having said this, I will rebuild the gearbox with moly synchros. Should I switch to the newer style internals?
 

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Discussion Starter · #130 ·
I think Richard Jameson at RJ Racing ( also here on the BB) will slightly disagree. The new (non-OEM) moly syncros have been of widely varying (and poor) quality. He's said the older - grooved - OEM syncros are what he collects for his racing customers.

Since you are in Europe, also check with Max Banks at Alfaholics (in the UK) about what rings are best. For all the work of totally disassembling a TX, you'll want to have the best syncro rings you can.

BTW - the brass shift rings that go over the snycros are also different between the older and newer designs. Be sure to get a matched set.

Robert
 

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Thanks Robert, for your input.

Car will be used on the street (no racing), and i will combine several good but used moly synchros from other transmissions. I understand that the issues are mainly for racing apps, and with inferior repro synchros.

Will check with alfaholics anyway.
 

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Discussion Starter · #132 ·
I just want to thank all the Alfisti on the BB for their interest in this thread. I am awed and honored to be blessed with a sticky for this mod - it seemed to be so obvious when I tried the fix in 1971!!

I also thank all the contributors on how to pull the worn dog-teeth unit for a less-worn 4 or 5 gear unit. For all those who don't know yet - APE and others are collecting good dog teeth sets.

Robert
 

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Just got my S2 transmission rebuilt by Rich at Continental Motors. I had him do the first gear fix.

Wow! What a difference!

Thank you 60sRacer for sharing this mod.
 

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Synchros

Hi,

Just swa and read this thread, excellent information. I also do a lot of Porsche's and there are tools ( not cheap ) to specifically remove the dog teeth, I have these and they work great for removing and installing the dog teeth. Also, these parts for the synchros ( which Porsche calls them brake bands and anchor blocks ) are all available individually and not that much. I will have to look through a Alfa box and compare them with my Porsche stuff. I am sure that something will fit and can be readily availble.

I am certainly will do this to my gearbox once I get around to rebuilding the box.

Thanks, Rick
 

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Discussion Starter · #136 ·
Thanks to everyone. After over 40 years, I am still amazed that Alfa took a HIGHER cost approach - unique 1st gear dog set and parts - to make a WORSE design for the transmission syncros.

Will we ever understand our quirky Italian cars? Do we love them BECAUSE they are so weird?

Robert
 

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Hi all

Can someone lay eyes on my version of this fix - I replaced both sectors and both arcs from a 2-5 style synchro into my existing 1st. Looks right?

Old 1st gear pieces off the the left, canabalized synchro to the right.

Thanks
 

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Hi all

Can someone lay eyes on my version of this fix - I replaced both sectors and both arcs from a 2-5 style synchro into my existing 1st. Looks right?

Old 1st gear pieces off the the left, canabalized synchro to the right.

Thanks
Yes. You have set up the synchro bits correctly.

I have not personally tried the fix using the same 1st gear dog (with 2 openings) because mine were always shot, but you should not have a problem with the way you have it assembled.
 
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