If I don't give enough clutch 3rd will grind engaging...

Thats when I'm shifting quickly...

Or is a syncro going bad?

 

I'm not sure about you loosing a syncro or not but do remember that the nv4500 is a truck transmission. This isn't a little honda you can go around snicking gears in. I think if you figure out how to shift without the clutch you'll be even better off. Teaches patience and the ability to feel the tranny. You won't need syncros.

 

You can shift w/o the clutch?

Man, I'm a n00b...

 

I do this all the time- and now that syncros are completely toast on my 3rd gear, I "double clutch" going into 3rd, and when downshifting, I don't use the clutch at all... I can match the RPMs better with the clutch out..

that's all the synchros do- match the RPM of the input shaft to that of the speed of the gear you're selecting... 3rd gear seems to wear out first- from what you're describing, yours is pretty worn, but it's not shot yet... go easy on it, or you'll lose 3rd synchro completely... then you get to find out what it's like to drive a big rig- especially older ones didn't have synchros, just big straight cut gears (makes the tranny stronger), you had to match rpm's on all shifts

since I figure you'll ask, double clutching works like this- when you're ready to upshift, let off the accelerator while pushing in the clutch- move into neutral... then when the engine revs down from you letting up on the accelerator, momentarily let out the clutch, this will slow the rpms on the input shaft to that of the engine- then push it back in, put it in the next gear, and let out the clutch while applying accelerator again...

if you get the timing right, you don't work the synchros at all- I can hit 3rd gear consistently even tho the synchro is completely shot... just takes practice...

downshifts are trickier, but you can double-clutch a downshift, too.. use the clutch to take it out of gear, then let it out & rev the engine to the RPM for the gear you're downshifting to, then push in the clutch again, and push into the lower gear... This is sometimes used in sports cars to reduce the load on the synchros while skipping gears on downshifts (like 5th to 2nd)

it's better to practice these techniques on a car with a cheap transmission.. (like my neon- 2nd gear synchro was gone when I bought it, can get another transmission for $75, not $800-1500 like the NV4500)

 

Yes, I shift without the clutch frequently too. And it did take me a little bit when I first got this truck to get used to slow shifts. But I have driven other heavy trucks before so it wasn't too hard.

Even when using the clutch, it makes for smoother downshifts to match engine speed before you release the clutch.