Transmission Rebuild - You can do it!

[MyAlfa]

Early this year when I had my spider engine out, I decided to rebuild the gearbox and get rid of that 2nd gear grind! I have never opened one up before and was concerned that parts would fly out just like the exploded drawing. Well, it turned to be straightforward and fun.I recommend it. If you can get the tranny out of the car, you can rebuild it.
I used the Centerline recommendation for a minimum rebuild. It is on their website. The parts are less than $200
The workshop manual makes the process look long and difficult, however, most of the parts don't need to be removed. Once the gearcase is open, the only thing that needs to come out is the main shaft assembly. Pulling the gears off the shaft is easy. You don't need a hydraulic press. I just used a 3 arm puller that I made extension arms for out of some perforated bar that i got from the hardware. The teeth on the arms can be hooked over the gear. It won't hurt the gear because it doesn't take much pressure to get it moving.I was concerned about keeping track of the parts, but hey, each gear is a different size. It goes back together just like in the picture.
There were 2 other potential concerns. One was getting into the syncromesh units. That turned out to be a breeze. Remove the retaining ring, replace the syncro ring, put the retaining ring back on. The other was getting the syncromesh hubs back on the shaft. They need to be heated before they will slide back on the shaft. It turned out to be no problem. I just put them in the toaster oven for a few minutes and they went right on.
Rebuilding the gearbox was well worth it.When I am driving now, it is great to come into a curve hard, pull it into 2nd and accelerate on through the curve.

Mike
79 spider

[Ital_Nut]

Awesome!
I got mine done(79 Spider also) with a shop alittle while back and have a spare tranny to practice on. Still have a first gear grind on occasion.

Hope you took pics and can post a step-by-step procedure.

[lowmileage]

I've read (but have had no experience with) that it is a good idea to have the gears lightened if you're doing syncro's. It will cost a bit more but will give faster (smoother ?) shifting and make it easier on the syncro's to slow down the otherwise heavy Alfa gears

[MyAlfa]

Yes, I did take pictures. Unfortunately, they must have got dropped in the trash bin because I can't find them. Since you are working on a spare tranny, I recommend that you just dive into it. It is more straight-forward than you would think. The gearbox is solidly built and I believe that it would be unlikely that you will break any thing. My recollection is that I spent more time studying the manual than I needed to.Many of the steps are intuitive.
As to your 1st gear clash, I have read in other posts that the alfa gearbox does not have a fully syncronized 1st gear. If you touch 2nd gear before shifting into 1st, it solves the problem.
Lightening the gears might be an interesting project. They are definitely very substantial. If I understand it correctly, you drill out a portion of each gear. It seems like it may a challenge to keep them balanced as you remove the excess metal.

Mike

[Gordon Raymond]

I'm wondering about the toaster oven. Humm? Was this industrial 220V or just a little toast warmer? Every time I've seen this done, HEAT and FORCE were required. Sometimes, considerable HEAT and FORCE. Why do all the real good Alfa shops, have all those expensive Snap-On pullers, and BIG presses if they only need a little toaster oven? I've watched this process quite a few times in the past 40 years, and never been lucky enough where a little warming would do the job. The pictures would have been wonderful! Even with high pressure assembly lube, when I press the thing together, my face looks like this.. or sometimes this... Best, Gordon Raymond

[Ital_Nut]

One of the local Alfa mechanics did recommend to shift into a higher such as 4th gear before engaging 1st gear to slow the gears or is it speed them up?.. to avoid the crunch! So I instinctively do it all the time now!

Thanks for the motivation!

[andrewg]

You replaced the synchro and shift sleeve, but did you replace the dog ring? Without replacing the dog ring, your transmission rebuild will not last long. The crunch you used to hear was the shift sleeve and dog ring "rubbing" against each other while they are not engaging. The crunch is the teeth being chewed up.

[MyAlfa]

The toaster oven is actually a small oven that I set the temp. at 400degrees and put the syncro hubs in for 10 min. I read this suggestion somewhere, probably a post here. Then I used one of my wife's oven mitts(If she only knew) and pushed the hub over the main shaft. I don't recollect it taking a lot of pressure, although I do remember thinking that I needed to do it quickly or I would have to use the puller to get it off and then start over. From what you are saying, Gordon, I just may have been unusually fortunate.
Concerning the dog rings, I am not certain what they are. I have looked at the drawings and don't see dog rings.What I replaced was syncro rings, syncro sleeves, and seals as recommended by Centerline. I looked over all the parts carefully before putting it back together and did notsee any unusual wear. If I had found any chewed up gears, I would have replaced them. I do agree that this will not last as long as a total professional rebuild.
Mike

[andrewg]

The dog rings from Alfa were not sold separately - only with gears. If you look at the gears, where the synchro sits in, that is the dog ring. It has the raised center section and the outer edge has small teeth that the shift sleeve engage and lock on to as the sleeve passes over the synchro. Unless you really look, you think they are part of the gear. The can be pressed off and on. The difference between a bad and good synchro is the shape of the teeth. Having rebuilt hundreds of 105/115 and GTV6/Milano transmissions, the dog ring is the difference between having the transmission rebuild last a few weeks ans a few years. I will post of pictures of a dog ring when I get to work today.

[Craig]

G'Day Guys,

Plenty of pics and removal info for dog gears in this thread Dog Gears, how to remove and what to look for.

[MyAlfa]

I just looked at the thread, Craig. It has good info-lots of detail. Incidently, I spent some time in New Zealand a while back and a Kiwi friend described Australia as that little island off the coast. I was entertained. Apparently there is a bit of a rivalry between your 2 countries.

Well, after looking at the photo of the worn dog gear, I definitely would have recognized that as a problem. So, I would have to say that mine were in good shape. I did the rebuild in February and 2nd gear is still crisp.I don't believe that I actually ground the gears in the past. It was more a case of knowing that I had to downshift slowly and allow a little lag time.

Mike

[Steve Cohen]

Hi All
I sourced dog gears for my 105 from Avanti Spares in Brisbane Australia
Steve

[Bill77]

Alfa Parts Exchange (APE) carries good spare dog gears in the U.S.