ALFAGTV6.COM

[zambon]

I am rebuilding my verde transmission with some new synchros and I have decided to have my gears lightened while I am at it. I talked to a machinist friend yesterday and he offered to do the work for me. Then he offered to make entirely new gears instead.
If I had him make me new gears, what types of treatment would the gears need after fabrication? I have seen the term ¨shot peen¨ often on this board, but I am unfamiliar with this process. Could someone educate me?
What about this idea of having new gears made? Is this advised? I assume it would be difficult to match the quality of the factory gears.
I could also have him make me gears with different ratios, I guess. I am no engineer, however, and I dont know what to go with.
People are always debating different engine-transmission combinations, but what about a new set of ratios? I could have my friend make the gears at an attractive price (compared to some of the prices that have been discussed here on the board). I personally have no interest in a race box, but I am interested in furthering the cause of our cars, since they are not making new ones anymore (w/rwd anyway).

[MerrilGordon]

That sounds interesting Zambon. People here are pretty happy with the "Platinum" transmission and the 4.10 R&P, but I like the taller ring and pinions of the Verde and 82-83 transaxles. My idea of an ideal ratio would be stock Milano 1st and 2nd, but then a 3.0 third rather than the taller stock Milano gear or shorter Alfetta 3rd gear. Then the Alfetta 4th gear and stock Verde 5th. That gives one a nice close ratio transmission along with a tall highway cruising gear. I daydream (well at least while on the stairmaster at the gym) about having those kind of ratios.

Regarding heat treating, gear teeth angle, and all that, I'll have to defer to the other experts on this site.

Merril
GTV63.0

[zambon]

Top notch post Merril! Thanks for the advice. perhaps I will try to get my hands on some gears from the other transmissions for the purpose of copying them.

[Micke]

I assume your friend know what he is doing making the gears. Then he also must know the needed treatments. Hardening, polishing comes in mind.

Next you need to decide what you need the box for. Street use the original ratios are OK. (The new gears are also likely to be louder than OE) In this case there's no need to build the gears yourself. Then it would be much (and I mean MUCH) more economical to make a short ratio box, sell this and buy 5 original boxes for the money.

If you need a special ratio box, let us know. I have pretty good knowledge about the subject.

On the other hand - for street driving you don't need lightened gears either.

[ar4me]

On the other hand - for street driving you don't need lightened gears either.

Why not? It will extend the life of the rebuild (synchros) whether on street or track and should improve shifting with reduced rotating mass. I would think it is a nice feature even for the street if you can afford the extra expense up front.

Jes

[junglejustice]

I have to agree with Jes here; it IS a good idea for the street...

I went ahead and installed one of the two Platinum "race"-prepped boxes in my street Verde, just to run it in, test the machine shop's work, as well as that of the Heineken-loaded assemblers' work and to test the validity of the 50% lock-up and the merit in the lightened rear flywheel, check for leaks etc....

Basically, just to see if the damn thing works and to be able to run the Verde this weekend at PR since the 3.7 is not running yet. I will be switching back the long leg Verde box as soon as I have gone through it a bit – probably won’t go as crazy on it though - and then the race box goes in the 3.7 next month for a first run...

I must say, so far I have not been able to run it hard yet (still worried that the damn thing may fall out...) and everything is still pretty stiff. I CAN get used to these shorter shifts and the quicker, nimbler feel of the car with the 4.10 box versus the old 3.55:1 Verde unit that sucks off of the line…

It's tight right now, but the throttle is quite "blippie" I can't imagine what the damn 3.7 is going to be like with the front flywheel lightened SUBSTANTIALLY as well and with all of that power... I CAN hear the LSD working quite well coming out of tight driveway turns and there is the familiar shudder that I have seen, heard and felt at the wheels of the race cars from the LSD and the grippy clutch…

Andry Garcia's race clutch is just right for the track, but perhaps a bit grippy for the street - I don't mind it because I knew what to expect upfront. I would use it on my street car bu it takes some getting used to.

To recap:
These boxes were stripped down and the internals were sent to Andrew Garcia of Garcia Alfa Racing in Houston Texas. He had all of the 5 forward gears as well as reverse and even the idler gears cross drilled and back-cut for lightening. All of the gears were then shot-peened for strength.

All of the syncros were replaced, as well as some of the syncro sleeves. The LSD had its two existing friction discs replaced as well as two additional plates added for an approximate increase of the effective limited slip lock-up to 50%...

The clutch is a race unit also from Andy with the flywheel lightened about 16%.

Two beer-drenched individuals, (one-each South African and Danish), did the final assembly around midnight. We added some of Andy at Performatech’s “Monkey Shifter Kits” as well as some new seals from Group 2 Inc in Seattle.

Redline 75-90 oil (not the LSD oil...)

[zambon]

I only need original ratios for my own personal use. I would, however, like to have the gears lightened as that is widely considered to be a nice upgrade. I also am interested in longer synchro life.
The idea of making close ratio gears would be a for sale type proposition. Another thread complained about the difficulty of procuring close ratio gears in the US. I am not trying to capitalize on the situation. Mostly I would like to contribute to the alfa community in the US, which is very small in relation to the competition (ricers, bmws). My friend would need to make some money, however, as he is doing the actual work.
For my own project, I am interested in purchasing the avalable gears so that I may make my own box from available parts.
I am uninitiated as far as the nuances of the gears. I dont know about the racing setups (straight cut gears...) I assume that it makes more drivetrain efficiency at the cost of oprerator convenience. As well as noise and smoothness losses as well.
Am I wrong about anything here? Please continue to send forth any relavent points.

Thanks
James

[ar4me]

I have seen technical drawings for drilling and back-cutting of the gears at
http://alfa.denovich.org/twiki/bin/view ... Lightening

I have no experience with that particular set-up, but thought it could be of help to your friend.

Jes

[zambon]

Jes,

Thanks for the link. I have read the text of that article before, but I had not seen the technical drawings.
I am very glad to have them. Also, the other links within lead to much useful information.

[junglejustice]

By Day 3 and about 150 miles, this thing really started to loosen up...! What a pleasure - shift it fast - don't slam - bu don't pause either....

Running it in you want to get fast shifts in (less chance of a slow-down of all of the gears between shifts...)

The LSD REALLY works, I can feel it going around corners etc...

Took it to the track Sunday, with the GoTech now on there too... WOW! The clutch let up on some it's grippy antics; these Platinum ratios are the bomb!

Just awesome - Thanks Andy Garcia - great job!

[zambon]

JJ,

Do you happen to know the specifications that were used in your gear lightening project? Are they similar to the technical drawings in the link above?

Also, does anyone have anything to say about those drawings? Are they conservative? Can the cross drilling go all the way through? Am I thinking too aggressively here?

I am planning to go ahead with those drawings as my guide. I have the gears out, now .

James

[zambon]

here is a direct link to the drawings: http://alfa.denovich.org/twiki/pub/Alfa ... gSpecs.pdf

[tomp]

Could someone repost the gear lightening drawings again? The links are no longer working. Speaking syncros and gear trains its looks to me like the alfa tranny is backwards. The current design trys to "sync" a gear to the output shaft requiring that gear, the input shaft and every gear connected to the input shaft to change speed. Big job for a little syncro. What if instead the transmission was designed to sync to the input shaft? Think of it like this. Right now in neutral with input shaft turning all gears meshed to the input are rotating. If we reversed this so that in neutral, no gears are connected to the input shaft(freewheeling) when any gear is selected all it has to do in change input shaft and clutch disc speed. The only reason there might be a problem is lack of lubrication in neutral since there would be no gear splash. This seems obvious but there must be more to it. Anyone care to enlighten me on this?

[Daniel_Jansson]

here is a direct link to the drawings: http://alfa.denovich.org/twiki/pub/Alfa ... gSpecs.pdf

Anyone got this document??! Would be a BIG help

[hexen]

http://hexenberg.free.fr/75/allegement_pignon.htm