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Discussion Starter #21
So, how did this build go? Worth the investment? I ask because I will seriously look at this gear set in a few months.
Hey Pancho,

The build went by the numbers. I put the gears in a 1967 Duetto gear box with a mechanical clutch. With all the gears on the main shaft running on roller bearings it makes a noticable difference in shifting and the sound. But the big thing is the 2.67 low close ratio's are infinitely nicer than the stock Alfa ratio's.

To me it was definitely worth the investement. It transforms the entire car. Not to mention the old gear box was hemmoraging gear oil from every place possible and I HATE oil leaks. My assembly procedure eliminated all of the leaks. I have about 500 miles on the GB now and it's completely dry. All problems solved.

Happy motoring:

B :cool:
 

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So are there any of these sets out there that have been in service for a while longer than a year or two? I'd like to know the overall consensus before shelling out the dollars. I see the Rimicci brothers are Agents if OS Giken - any chance of some test case owners? Any known failed sets?
 

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Discussion Starter #23
So are there any of these sets out there that have been in service for a while longer than a year or two? I'd like to know the overall consensus before shelling out the dollars. I see the Rimicci brothers are Agents if OS Giken - any chance of some test case owners? Any known failed sets?
Paul Spruell has built 20 or so GB and sold them to racers, said no problems to date. Check with him. Also check with the Rimicci's. As I said mine is perfect. If you want to buy a GB assembly procedure that guarentees no leaks and a perfect job, get back to me. Check OSG's web site they sell a lot of stuff for rice rockets, the domestic Japanese markets and are a high end mfg using the latest materials and mfg processes. The roller bearings they use for 1st / 2nd / 3rd are the same as the stock 5th gear in the Alfa GB and I have yet to hear of any 5th gear roller bearing related failures. OSG has been selling these gear sets in Japan for a long time so they have history with the product. Do your research and convince yourself.


happy motoring
b:cool:
 

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Os giken quality

Group 2 Motorsports is a dealer for OS Giken. To date I believe we have built twelve to fifteen differentials for local BMW racers and would attest to the quality of their products.

We have experienced NO quality issues with the product.
 

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OSG gearsets

Interesting conversation. Thought I would wait a while and see what came along before offering my comments. No worries! We have sold over 30 of these gearsets without a known failure. So, let me address some of the concerns submitted.

The syncro teeth on the gear mesh with the sliding syncro sleeve. This unit is pressed onto a splined hub in the standard Alfa gears. Conversely, the OSG syncro tooth unit is welded onto the gears and as Richard points out, can be removed and a new one welded in place if necessary.

The stock 5th needle bearing is much smaller and is a comfortable fit in the 5th gear with room to spare. The 1st-3rd journals are much larger and require a much larger bearing. The stock copper bushing is very thin and allows room for splined mounting of the syncro unit.

Why do the OSG syncros need to be welded instead of splined? This is a neat piece of engineering. I have always made my own gears, hated the copper bushings that go bad and tried my best to fit 1st-3rd with needle roller bearings. The limiting factor was that the copper bushing is very thin and the needle bearing is much thicker. There was simply not enough meat to bore out the hole to fit the needle bearings. One has to machine off most of the metal base supporting the mounting splines to accomplish this. I even selected the same needle roller assembly that OSG ultimately used, but could not make it work. Mr. OS ingeniously attached his syncro unit by welding which leaves sufficient meat to bore out the cylinder to fit the needle bearing.

Bill has done a very thorough job documenting the metallurgy. So, I see no stones left unturned with regard to the quality or functionality of the OSG gear sets we have been selling for several years.

The only thing that has not been mentioned is that performance can be enhanced by REM finishing the gear sets before assembly. This is a process that tumbles the gears in a matrix of special stones and a chemical bath of polymer solution. This micro polishes the tooth surface and works the polymers into the pores of the metal. For friction reduction and longevity, this process is superior to any coating. This makes the gears so pretty that it is a shame to hide them inside a gearbox.

We have REM finished several sets for customers since Bill made his purchase and have now decided to offer it as an option on our website. This also works wonders for ring/pinion sets. Every little bit of friction reduction from engine to differential adds up to significant reduction of parasitic power loss.

Unfortunately the current prices will increase with the next run of OSG gearsets delivered. We currently have (probably) the last of both the close and super close gearsets on the planet until the next batch is done, so grab one now if you have been inhibited by the misinformation. ( Please note that some pricing on our ABB ads need correction, but they do not perform that service that anymore. So it will have to wait for us to generate new ads. )
 

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Thanks for these comments Paul. I too have been lurking here!
 

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Discussion Starter #27 (Edited)
Thanks Paul. It would seem there are no stones left unturned regarding OSG gearsets??? I have one thing to add: Before installing the OSG gearbox I filled it with 75-140 Mobil 1 synthetic gear lub and it shifted pretty well. OK so the GB has about 1K miles on it, the car was up on stands for something else, so I decided to change it. I wanted to see how much metal was on the drain plug magnet after doing Paul's synchro ring pre-wear-in procedure when I built the GB. BTW: there was zilch metal on the magnet (as in almost none), thanks Paul great idea. So I went back to my old standby Lucas 85-140 heavy duty gear oil on the change. The difference in shifting was night and day. The Lucas oil has some additives that make it stick to the parts such that the GB shifts so much easier it's almost laughable. Am guessing the stickier Lucas oil is adhering to the synchro rings and sliders so they lock up faster during shifting. There's less bearing noise as well. Based on what I have seen here, there maybe merit in using the OSG gear oil which is heavier still???

Happy Motoring,

b :cool:
 

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I'll take that set Paul thanks for your info.

I have a condition unknown GB and I'm going down this path anyway. I'll put my trust in OSG and what others have said and see what transpires.
 

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Discussion Starter #29 (Edited)
OSG gear material

Found out the gears are made from a JIS version of 9310 steel. Which is an updated version of 4000 series steel with lots of chrome and nickel... Very tough stuff. If you want to know more go to the ANSI standards and look it up.

Happy Motoring

b :cool:
 

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Has anyone really re-welded a carrier on personally, and it stayed together? I have been down that road with a Colotti gear set, same story syncro carriers are welded on, Have tried welding, pins and welding etc. etc. and they kept breaking after a few races, Other problem is welding distorts needle bearing bore and that has to be refinished. OS has the luxury of welding pre hardening.

ZF has had welded on carrier failures in stock trans, 94-95 LS especially 1st gear with the multiplied torque load they shear off and no luck fixing one of those either. Pretty bad spending 8 hours putting an LS trans axle back in and two days later it's broken again. Customer not happy.

That is my personal experience with welded carriers, I take splines any day.

Larry
Alfa Parts Exchange
 

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Don't know if he's reading this Larry, but Richard Jemison probably has done that.
At Ausca we ran the Colatti gear-set without synchronizer hardware as a crash box. At that time, we were distorting the cases in longer races, and used the Colotti set, lightened, and made to run without synchronizers. This worked pretty well as I remember, and the GTA cases shaft bores remained round. This was a loud transmission in use, but on the track it didn't matter.
 

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Discussion Starter #32
Don't know if he's reading this Larry, but Richard Jemison probably has done that.
At Ausca we ran the Colatti gear-set without synchronizer hardware as a crash box. At that time, we were distorting the cases in longer races, and used the Colotti set, lightened, and made to run without synchronizers. This worked pretty well as I remember, and the GTA cases shaft bores remained round. This was a loud transmission in use, but on the track it didn't matter.
Regarding 9310: I'm not sure that you need to harden this material. I believe they make heat treatable grades however. Can't get any information about secondary operations on the gears from OSG... Had the get the material info from a second source.

I believe Gordon is correct: Richard Jemison would be the guy for gears.
 

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We sell Richard tons of core trans axles, LSD carriers, cams, spindles, LSD clutch plates, etc. etc. Back many years ago I told him how to stop burning up transaxles, by keeping track of/ checking the pinion shim stack. I will ask him next time I talk to him.
The gear teeth are hardened, including OS, and that is the issue, the welding after the fact, creates a very hard to relatively soft transition between the two parts and it fatigues. The only one out of the Colotti sets that has not broken is one done differently as far as how the old carrier was removed in that the original welded area was left alone and just the outer ring of teeth were cut off, thus the new weld was only between the two parts of a carrier, which is softer than the gear, avoiding the extreme range in hardness.

I have succesfully put needle bearings in stock alfa gears (1st, 2nd, 3rd)and Hybrid ratio sets, I run a set behind my 235 hp V-6 GT on the street and track.

APE
 

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Welding on / in gears

Yes, Larry is a great source for Alfa parts and we are very lucky to have such a source.

Unless gears are protected from heat they are going to be annealed from welding. All of my modified gearsets are welded, but I have built "fixtures" (I used to call them "jigs" but they are far too useful to have them correlated with our president) that allow them to be immersed in a solution while being tig welded together. This keeps the gear teeth well below critical temps.
The only gear that gets the syncro welded is the 1.69 2nd gear for the 105/115 CR boxes. This is a 4th gearset that is reversed and the layshaft gear bored for roller bearings on the mainshaft, and syncro assembly welded to it.

I do this because I have the time(retired) and capacity. It is far easier to buy the gearsets than do this foolishness.
With less than great new replacement parts that are out there, you have to be far more attentive to building these things than just buying parts and assembling them together. See the thread on Syncro issues on the BB.
 

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I do agree that for a quick and easy solution buying the gear set is the way to go. I was only commenting on the original theme of feedback about the OS gears, and I wish they did not weld them.

APE
 

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Thanks RJ. I also feel better that I'm not the only "retired" guy that participates in "foolishness" for the sake of a job well done. Having the time to think about this stuff, and how to do it correctly is good for us.
Just my opinion. Same with "fixtures". I've lots of those now as well.
 

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Discussion Starter #37
Just scrolled thru the synchro thread and saw the OSG gear sets that now have Nissan synchro sub assemblies... Assuming the Nissan parts are pretty much proven new technology, as is the gear material, method of fabrication and secondary operations, appears there is a path to update alfa GB's to modern technology and live happily ever after. :)
 

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Thanks Larry for chiming in. I was hoping Merrit wasn't the only one displeased with the design. His feeling might be a bit strong, but at least another expert concurs. I have not been back to talk to him more about it yet but did confirm from two other bay area experts that is was indeed an OS 1st gear that blew the synco teeth and OS has replaced the 1st gear at no charge.

This is good for OS reputation as they stand behind their product, but I wonder if the supplier of that box is aware of this particular failure and if it's the only one ever. I wanted to also ask him if he was sent the replacement gear or if the box was returned to the supplier for repair. There remains at least one supplier that cannot claim no issues with the boxes they have sold. Maybe it's moot since the gear was replaced at no charge. Was there a charge for the labor, I wonder?
 

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Richard Jemison
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Nothing New Under the Sun

An old Datsun racer told me over the weekend, that not only did these cars (Alfa 1600 & Datsun 510) share cam drive chains, they used Alfa syncro parts in their transmissions to improve shifting.......
It`s all metal...:p
 

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An old Datsun racer told me over the weekend, that not only did these cars (Alfa 1600 & Datsun 510) share cam drive chains, they used Alfa syncro parts in their transmissions to improve shifting....... It`s all metal...:p
Now that's an interesting piece of information, Richard. What if OSG discovered a parts interchangability that nobody knew about?
 
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