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Discussion Starter #41
Look at the pictures posted by bill77 on page 2 of this thread. To make the first gear match the others, you need to replace the key at the top of the first gear (has a hook on one end) with one from the other gears, and add the second arc piece.

That's all. You can take these parts form an old gear - they do not wear.

As I said above, the hardest part of this is getting the big snap ring off the gear. I bent a few cheap snap-ring pliers before I found one strong enough!

Another part of this thread describes changing dog teeth. These are pressed on the gears, and are identical for all gears. Only the 1st and 2nd really wear much where the dog teeth get blunted. If you have some old gears, pull the dog ring off from a good 4 or 5 gear and use it on 1 and 2.

Robert
 

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Look at the pictures posted by bill77 on page 2 of this thread. To make the first gear match the others, you need to replace the key at the top of the first gear (has a hook on one end) with one from the other gears, and add the second arc piece.

That's all. You can take these parts form an old gear - they do not wear.

As I said above, the hardest part of this is getting the big snap ring off the gear. I bent a few cheap snap-ring pliers before I found one strong enough!

Another part of this thread describes changing dog teeth. These are pressed on the gears, and are identical for all gears. Only the 1st and 2nd really wear much where the dog teeth get blunted. If you have some old gears, pull the dog ring off from a good 4 or 5 gear and use it on 1 and 2.

Robert

OK, lets say I dont have a spare trans to scavange from......can I buy these from say, IAP, provided they are the parts (bits/arcs) from other than the 1st gear? Why cant I use the arc that is currently in the 1st gear now and add a new one? Whats the deal with the 1st gear bit being so "special"?
 

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Discussion Starter #43
Try Alfa Parts Exchange in Plesanton. They are in the BB suppliers thread. Lots of used parts.

Roberta
 

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Yes, that's right, except that you have a choice to retain the original 1st gear dog ring if you want, or switch to a 2nd through 5th style dog ring.

Otherwise, the synchro ring, sectors and straps must all be either 1st gear style or 2nd to 5th gear style. None of these pieces can be interchanged.
Ahaaaaaaa!! Found it!

So, this means IN NO UNCERTAIN TERMS, to do this mod, you MUST scrap (remove, and discard) the 2 bits, AND the one arc, AND the synchro ring, then replace with a set from other than 1st gear (both bits, both arcs, and new ring for that gear)?

(As I have not yet gotten to pressing out the gears to open up insides, I cant measure things yet, thats why Im confirming up front, anticipating my process.)
 

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Discussion Starter #46
...IN NO UNCERTAIN TERMS, to do this mod, you MUST scrap (remove, and discard) the 2 bits, AND the one arc, AND the synchro ring, then replace with a set from other than 1st gear (both bits, both arcs, and new ring for that gear)?.
Not quite. The syncro rings get replaced for wear issues - they rub on the inside of the bronze shift slider rings. To do this mod, all you need to change in the first gear is replace the upper hook like segment with one from a higher gear (that has no hook), and add a second arc segment. The other arc stays, and the lower bit stays.

All the syncro rings are the same on all five gears; the lower bit is the same; the arcs are the same (except that 1st has only one); the upper bit is different only on 1st and must be replaced. Just make all five gears look alike.

There are wear issues with the dog teeth, the syncro rings, the bearings, the shift sliders. I've had alignment problems with the reverse idler gear - the shift fork arm is long and a bit flimsy if you try backing uphill in San Francisco (that's how mine got bent a bit). Shims and spacers that fit the front input shaft to the main output shaft are critical as described in the Alfa transmission handbook.

Robert
 

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You keep shedding light on this subject, Rob. My hat's off to you, and you're continued patience while I digest/understand getting ready for the big day.

Yeah, I will look at the fork surface where it rubs against the sleeves (the ones in my spare trans on my bench are worn, from a car with 98,000m), and I will eventually post some pics of them for comments. Of course, I will probably prefer to keep the forks from the car's trans, which only has 60,000m on it.

Now bearings, if they spin nicely/smooth/no noise, tight, I assume they are good? Thats what I understand.

Joe
 

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Oh, another thing....regarding sealing that trans from notorious leaks. One thing I cant tolerate is oil leaks , and this will be my chance to get it done right. I have strong suspicion that the stock oil seals (both front/back) are not made right. Why? cuz 3 yrs ago, when I had the trans out for a clutch redo, I figured Id pop in a new front seal. USELESS!! Leaked within 6 months. Typical alfa substandard engineering!!!!!!!!!

Man, I got a mind to look for better seals than what is sold in the catalogs, seals with double "lips"(?) Also, Type II mil spec aircraft engine gasket sealant on the milled surfaces. Anyone have luck with different seals on this trans?
 

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Oh, another thing....regarding sealing that trans from notorious leaks. One thing I cant tolerate is oil leaks , and this will be my chance to get it done right. I have strong suspicion that the stock oil seals (both front/back) are not made right. Why? cuz 3 yrs ago, when I had the trans out for a clutch redo, I figured Id pop in a new front seal. USELESS!! Leaked within 6 months. Typical alfa substandard engineering!!!!!!!!!

Man, I got a mind to look for better seals than what is sold in the catalogs, seals with double "lips"(?) Also, Type II mil spec aircraft engine gasket sealant on the milled surfaces. Anyone have luck with different seals on this trans?
I know the trans forum is basically a quiet place, but I figured a week should smoke out some owners with leaks, no?
Interesting.....guess Im the only one who has a leaky trans and is unhappy about it...LOL!! Hey, Ill figure it out........
 

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Discussion Starter #51 (Edited)
The seals work fine generally. Be sure the seal surface on the input shaft is smooth, and it is really important that the front bearing is good. The input shaft - output shaft spacing is critical to the health of this bearing, so the shims must be right on.

Also, any misalignment of the clutch, or out-of-balance will damage the front seal.

But also be sure to get the shift rod o-rings right!

THe output seal rides on the yoke. This should be polished carefully too.

The hardest part of sealing the tx is the split case. I've used blue silicone successfully. Post a q in the transmission thread to see what others do.

Robert
 

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use what the *** cars use that never leak. somthing like yamabond
 

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I put two input shaft seals on my last transmission. The first one leaked like a seive. So far the second one is holding. A double lipped seal would be a good one to have. My understanding is that the seal gets scratched going over the ribbed surface of the input shaft. I have always liberally greased the shaft before putting the seal over it just to make sure the seal slides easily. The 1st gear modification is going in on the next transmission, as it is an easy thing to accomplish. Should be interesting to note how easy the gear will engage when coming to a stop. I use Permatex Aviation on my transmission surfaces and they never leak.
 

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Thanks, guys. Interesting, as always, the new info out there.

Hey Robert, how come i did not see any shift rod o rings on that trans I have on my bench (you know, the one you've been coaching me on) . I took it apart, and split the case, and no o rings visible.......3 shift rods, so 3 o rings, right??

Yeah, aviation grade is tops for me. Type 3 mil spec.......
 

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Richard Jemison
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shift rods

all three gear selector rods are fully internal. The shift rod uses an oil seal.
 

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On the split case machined sealing surface, no matter what actual goop you use, (and yes, it's yamabond or ultra gray that's used on the Asian imports), you can get more effect and a lot more peace of mind if you run a silk thread along the machined surface to the inside of any bolt/stud holes.

The thread, and it must be silk, compresses when things are tightened down and works like a sort of micro-gasket or very thin o-ring that doesn't need a groove. (works great for 2 & 4 stroke motorcycle engine cases and split gearcases)
 

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Discussion Starter #57
all three gear selector rods are fully internal. The shift rod uses an oil seal.
AFAIR, on some of the earlier transmissions - like my 67 duetto, the reverse switch is mounted inside the bell housing. The three shift rods extend thru the front of the TX (one pushes the reverse light switch), with o-rings inside the case to seal them. Later tx's have shorter shift rods that do not go into the bell housing, and the reverse light switch is elsewhere.

R
 

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I put two input shaft seals on my last transmission. The first one leaked like a seive. So far the second one is holding. A double lipped seal would be a good one to have. My understanding is that the seal gets scratched going over the ribbed surface of the input shaft. I have always liberally greased the shaft before putting the seal over it just to make sure the seal slides easily. The 1st gear modification is going in on the next transmission, as it is an easy thing to accomplish. Should be interesting to note how easy the gear will engage when coming to a stop. I use Permatex Aviation on my transmission surfaces and they never leak.
Alfa has/had a tool to protect the seal from the input shaft. Essentially a thin wall piece of tube. I made one out of Aluminum.

FWIW

Ken
 
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