2nd gear synchro on its way out

[WA1DH]

I think my second synchro is starting to bite the dust. It started acting up the other week so I changed the tranny fluid (likely original). I replaced the ATF Ford put in there with some 15W40 Shell Rotella (synthetic) and the other gears shift smoother, but no such luck on second. When I go to pull it into second, sometimes it feels like the synchro isn't 'grabbing' (no 'click' feeling like the other gears) and I get a quick CRUNCH as it goes into gear. I assume the crunch is the gear teeth gnashing. I can usually avoid it by double-clutching into second at lower RPM (1500-1800ish) and accelerating in second rather than first, but if I have to get moving fast I don't have time to wait for the RPM to fall to rev match and it crunches into gear.

I know I'd have to pull the tranny to fix it (which I'm not doing until it needs a clutch), but should I be worried about the crunching into gear every now and then? Am I going to have second start popping out on me eventually? For what it's worth, I checked the old tranny fluid with a magnet, and no gear teeth - just some magnetic dust (metal shavings?).

[RITmusic2k]

Sounds like you're doing all the right things... As long as you DC as much as you can tolerate, you'll extend what life the synchro has left... and if we're talking about situations where you don't need to get going fast but you want to get going fast, I'd just wait the two seconds for everything to spin down. Two seconds ain't gonna make you late for work and the car behind you has no right to insist that you accelerate at a certain rate.

[LHOswald]

Sounds like you're doing all the right things... As long as you DC as much as you can tolerate, you'll extend what life the synchro has left... and if we're talking about situations where you don't need to get going fast but you want to get going fast, I'd just wait the two seconds for everything to spin down. Two seconds ain't gonna make you late for work and the car behind you has no right to insist that you accelerate at a certain rate.

QFT

the best thing i can tell you to do is just use 1st as a tool to get going, and get it into 2nd as soon as possible, and in the lowest RPM range as possible. this will make the synchro have to move the layshaft proportionally less, therefore reducing wear. if you combine that will DCing you should have virtually no wear and it should last you awhile.

I know I'd have to pull the tranny to fix it (which I'm not doing until it needs a clutch)

so just burn out the clutch quick so you can get a new clutch and get the tranny fixed

[WA1DH]

so just burn out the clutch quick so you can get a new clutch and get the tranny fixed

So you're coming over to help pull the tranny?


I tried being a little more gentle shifting tonight and it looks like the synchro still has some life left. If I gently slide it into 2nd and let it sit at the gate, the synchro works. If I tug it in it grinds. So maybe I can get away without double clutching for a while longer. Not that it's such a burden to DC if I have to.

[Rope-Pusher]

Just remember: The gears are in constant mesh, so you aren't grinding the gears, just 'Crunching" the synchros.

[theholycow]

Would skipping 2nd in hurry situations be useful? If you take 1st up near redline and then go straight to 3rd would that provide the acceleration you need?

Just remember: The gears are in constant mesh, so you aren't grinding the gears, just 'Crunching" the synchros.

Could he be crunching the dog teeth?

[Rope-Pusher]

Would skipping 2nd in hurry situations be useful? If you take 1st up near redline and then go straight to 3rd would that provide the acceleration you need?

Just remember: The gears are in constant mesh, so you aren't grinding the gears, just 'Crunching" the synchros.

Could he be crunching the dog teeth?

That would be cruelty to aminals! Yeah, they take a beating when you clash the synchros.

[LHOswald]

you dont live that far away. how far away is it from where you live to enfield?

[Rope-Pusher]

Hey, LHO!
Yanno, that really is an atypical representation of an Amish transmixer.
There is no synchro connecting the input shaft with the output shaft for a 1:1 ratio.
Based on the gear diameters, Reverse doesn't seem to have enough gear reduction.
5th doesn't seem to be a 1:1 ratio, let alone an overdrive ratio.
and those colors! Those gears clash sitting still!

[LHOswald]

Hey, LHO!
Yanno, that really is an atypical representation of an Amish transmixer.
There is no synchro connecting the input shaft with the output shaft for a 1:1 ratio.
your right, there should be a synchro in there
Based on the gear diameters, Reverse doesn't seem to have enough gear reduction.
looks about right to me
5th doesn't seem to be a 1:1 ratio, let alone an overdrive ratio.
5th output gear and the 5th layshaft gear seem to be about the same size. but your right, 5th usually is an overdrive ratio. must've just made it easier to draw?
and those colors! Those gears clash sitting still!
the colors are for automatic drivers. they suck them in and get them hooked on our MTs!

[Rope-Pusher]

Hey, LHO!
Yanno, that really is an atypical representation of an Amish transmixer.
There is no synchro connecting the input shaft with the output shaft for a 1:1 ratio.
your right, there should be a synchro in there
Based on the gear diameters, Reverse doesn't seem to have enough gear reduction.
looks about right to me
5th doesn't seem to be a 1:1 ratio, let alone an overdrive ratio.
5th output gear and the 5th layshaft gear seem to be about the same size. but your right, 5th usually is an overdrive ratio. must've just made it easier to draw?
and those colors! Those gears clash sitting still!
the colors are for automatic drivers. they suck them in and get them hooked on our MTs!

Reverse should have gear ratio similar to 1st, but with the idler in between.

[LHOswald]

but doesnt having 3 gears instead of 2 push the ratio up farther? even if they are smaller? im not sure how gear ratios work with more than 2 so IDK!

[RITmusic2k]

Everything between the input gear and the output gear can effectively be ignored. All it's doing is changing the direction of rotation. You could put three of those little gears between the input and output, and the ratio will still be the same

[IMBoring25]

An odd number of idlers, as stated, will change the direction of rotation of the driven gear.

Also, it is theoretically possible to have two gears locked to a common shaft. If that were used as an idler stage and the driven gear were driven off the second gear on the common shaft, the idler would produce a second stage of reduction or overdrive.

[RITmusic2k]

Also, it is theoretically possible to have two gears locked to a common shaft. If that were used as an idler stage and the driven gear were driven off the second gear on the common shaft, the idler would produce a second stage of reduction or overdrive.

If and only if those two idler gears were differently sized, of course.