'64 Dart 4 Speed Synchro Replace Mandatory Parts List?
Repointing synchros? Are you suing a Dremel or modifying a chainsaw sharpener, or?
I use a high-powered,high-speed, electric die-grinder, with tiny dremel-like cutting discs, that start out about 1.125 x 3/32
I probably spend less time repointing than back-cutting. On the coast-side of the sliders you will usually find 6 to 10 teeth that take the brunt of the deceleration forces. If the trans has been popping out of gear, then you will see the evidence on those teeth. That has to be fixed. The cure is to just cut that part of the teeth away, and then 6 to 10 other teeth will come on line.
Occasionally someone waits too long, and the drive-side shows similar damage, which I also repair, but being more precise, to not overload just a few teeth.
The clutching teeth have to be recut the same way.
After that, the brake-cones are straightened and polished, then I grind a bias on them do grab the brass in the upshift direction, except on low, I grind it on the downshift side.
After that, I fit the brass onto the input gear and line them up from best to worst. I put the highest sitting one on second, next is third, and then first. Fourth gets the left over cuz by the time you get to fourth, usually yur not in a hurry anymore,and if you are it's only once in a long while.
The second gear brass is the hardest working one. It always shows the most wear. I don't like to put new brass on it, cuz new brass is tricky; they rarely work right as delivered.
I modify all my 4-speeds for faster shifting at 7200. I only modify second and third, for use with 3.55s. This consists of cutting away every other clutching tooth and the first 1/8th to 3/16 of every other slider tooth. I also cut three broad shallow grooves in each brake surface,approximately equidistantly spaced around the circle.
None of this needs to be precision work, I'm pretty bush about it.
When you are done, you will be able to shift faster than the brass can at any rpm, but the brass will still work for driving around town . At 7200 it will shift so fast you sometimes can't find the shift tell-tales in the blackies.
As to the cluster-pins mine have 4 lives. I just cut new grooves for the keys as required and use both ends; it don't have to look pretty.
I tried real hard to use full synthetic oil, but it was too slippery, and shifted too slow; no matter what I did. I had the trans out 4 times in one week, trying different things, but nope,nothing worked.
So,in the end I went back to 50/50 Dextron II/75-90 dyno gearoil.
And we were back in action. All the mods worked with that 50/50 mix.
BTW, you probably don't need to shift yours at 7200,lol, but all the mods work just as good at any slower rpm,lol. Lightning I tell ya. And the brass will last for decades.
BTW-2
Only the low gear really needs the repointing, and it is easy to put too much bite on the brass, and then sometimes going from neutral to first with the car stopped, the teeth will butt and lock. Then you will have to put it in another gear to break the lock, before re-attempting first.
To not have this happen; firstly I try not to put too much bite on the first gear brake, and secondly I try to grab first before the car stops moving, and thirdly if already at a stop, I don't declutch and wait for the input gear to stop spinning; I just clutch, hesitate, and slam it in; Or I will clutch and put some pressure on the brake, but don't wait for the cluster to completely stop spinning. Just before it does, slam it in.You'll get the hang of it with practice.
I recommend not to use oil with 140 rating,I can't get that chit hot enough or thin enough, for fast shifting; 50/50 will work just fine.