Technical 39 Ford tranny grinds

I've got a T roadster with a 283 and a 39 Ford tranny. Most of the time it goes into low or reverse with no problem and no grinding.
However today it got real nasty and always wanted to grind going into low. The only way I can get into low without grinding a pound of gears is to shift into second and then real quick pull it down into low.
It can do this for a day or 2 and then be fine again.
Is this something to do with the throwout bearing or what else?
The clutch is mechanically activated and feels fine as it always has.
Thanks

 

1st and reverse are not syncronised and will grind if the car is moving. It sounds like your trans is OK if you don't keep grinding off a pound or two.

 

If you are stopped and it does it you might want to pull the top off and check it out. Drain the oil and look for brass. visually check synchronizer teeth......

 

Any non-synchro low trans requires the old "second first" trick.

 

1st and reverse are not syncro'd as previously stated. This could be interesting. I've rebuilt several of these so I'm tuned in for sure! Must have rpm's and speeds right if down shifting at speed. Sounds like clutch is not disengaging sometimes if it's when your stopped.

 

What weight of oil are you running. If it's super thin it might be more prone to do that. Basically sounds like you input shaft is still spinning a little even with the clutch in.

My bet is that the pilot bearing / bushing is starting to seize up a little.

 

Sounds like the clutch needs adjusting or the plate is sticking on the flywheel, causing input shaft to keep turning. When you put it back into second you are stopping the input shaft, and by quickly putting in to first before input shaft starts turning again.
I have had a clutch plate before that just wanted to stick on the flywheel not disengage but that was an aluminum flywheel.

 

This is where I'd start too. It's possible that the clutch disc has warped a little too. Check the clutch adjustment first before you tear it apart.

 

It is the clutch not releasing cleanly. It may need adjusting or may be contaminated with oil or grease.

Mart.

 

With practice you can learn the feel for the right RPM to make a down shift while still rolling but you could break a trans learning.

I always down shift into second while braking so the gears are not revolving inside after I come to a complete stop and shifting into 1st or reverse never causes any grinding. Part of the fun with a stick shift. IMHO Besides I like the sounds!