Transmission question, Brake bands on first gear Options

[Bartlett 914]

I am going through a transmission. First gear is supposed to have only 1 brake band. All other gears have 2 brake bands. Upon inspection, I find that my first gear is setup the same as all the other gears. It has 2 brake bands and the same stop blocks as the other gears. I really don't understand why Porsche did first different except to save money on 1 brake band. I do understand that synchronization is on the down shift and two may not be needed. Question is, should this matter? Is there some advantage to the way first was setup by Porsche?

[Richard Casto]

Ok, first, in my opinion what you have have is fine. It is what Mike taught me and I believe it is a valid solution to the more expensive 1st gear syncro hub.

Regarding "why" Porsche did it that way. I am looking at the factory manual and I don't want to retype everything, but in short, it appears they wanted the following action to be a bit smoother...

With car at a standstill, transmission in neutral and clutch engaged (input shaft is spinning at idle speed)

1. Engage clutch
2. Engage 1st gear.

The downshift from 2nd works like any other gear. It is the upshift from neutral they tried to optimize. It sounds like they felt that the different design allows for a smoother engagement of 1st gear. They talk about how the speed differential between the gear and the input shaft is low at idle when compared to what the other gears experience on an up/downshift. So I think they felt they didn't need the brake band to push against the inside of the syncro ring to cause more friction (which you would feel as you shift into first). I am curious if anyone is able to feel the difference.

Richard

[Bartlett 914]

Ok, first, in my opinion what you have have is fine. It is what Mike taught me and I believe it is a valid solution to the more expensive 1st gear syncro hub.

Regarding "why" Porsche did it that way. I am looking at the factory manual and I don't want to retype everything, but in short, it appears they wanted the following action to be a bit smoother...

With car at a standstill, transmission in neutral and clutch engaged (input shaft is spinning at idle speed)

1. Engage clutch
2. Engage 1st gear.

The downshift from 2nd works like any other gear. It is the upshift from neutral they tried to optimize. It sounds like they felt that the different design allows for a smoother engagement of 1st gear. They talk about how the speed differential between the gear and the input shaft is low at idle when compared to what the other gears experience on an up/downshift. So I think they felt they didn't need the brake band to push against the inside of the syncro ring to cause more friction (which you would feel as you shift into first). I am curious if anyone is able to feel the difference.

Richard

Interesting Richard.

I did have a problem with the transmission going into first from a stop. I always needed to go into first before stopping. This meant I had to hold in the clutch during stop lights. At a standstill, sometimes no problem. Other times no go. I was in the opinion I had the operating sleeve adjusted to close to reverse gear and I was running out of room with the shifter. Now I am wondering if the brake band issue was contributing to the fault. I do not plan to have this transmission in a car anytime soon. It will be awhile before I can test this an be sure.