sticky 3rd gear syncro

[ngobet]

Hi everyone,

I am building a gearbox and the 3rd gear syncro is really sticky.
What do you do normally in that kind of situation?

[Casting Timmy]

I put a rag over the pinionhead to protect my hand, or use a small prybar against the 1-2 slider reverse teeth to hold the pinionshaft still. Then with everything in neutral on the trans jig use an electric drill spin the mainshaft. I made an adaptor using an old coupler I cut the teeth off and welded in an old socket barely off straight.....been better to be perfect so you don't get a high speed wobble. It should loosen up and break in as you go.

Sometimes a new cone on the gear and a new synchro makes a high combo, you can also try putting a slightly worn synchro ring in instead. Some burnish the synchro cone on the gear with something to give it more grip, I tried it once and thought it made it too grippy.

[ngobet]

Thank you, that is useful, similar to what Berg said.
I was honestly wondering if I couldn't mount the gearbox and let the engine run in neutral. What do you think?

[Bruce2]

What brand of synchro is causing this problem?
I think VW said they ride at about 1.3mm above the gear when new and 0.6 is the point where you replace them. I've seen some new ones that were 1.6mm above the gear, but have never noticed a problem with it. Did you measure how high the synchros were?